KEY CHALLENGES IN MODELLING AN EPIDEMIC – WHAT HAVE WE LEARNED FROM THE COVID-19 EPIDEMIC SO FAR KLJUCNI IZZIVI PRI MODELIRANJU EPIDEMIJE – DOSEDANJE IZKUŠNJE PRI MODELIRANJU EPIDEMIJE COVID-19 Ivan ERŽEN1, Tina KAMENŠEK2, Miha FOŠNARIC2, Janez ŽIBERT2,3* 1 National Institute of Public Health, Trubarjeva 2, 1000 Ljubljana, Slovenia 2 University of Ljubljana, Faculty of Health Sciences, Zdravstvena pot 5, 1000 Ljubljana, Slovenia 3 University of Primorska, Andrej Marušic Institute, Muzejski trg 2, 6000 Koper, Slovenia Received: May 25, 2020 Editorial Accepted: Jun 1, 2020 ABSTRACT Abstract: Mathematical modelling can be useful for predicting how infectious diseases progress, enabling us to show the likely outcome of an epidemic and help inform public health interventions. Different modelling Keywords: techniques have been used to predict and simulate the spread of COVID-19, but they have not always been useful for epidemiologists and decision-makers. To improve the reliability of the modelling results, it is very COVID-19 modelling, important to critically evaluate the data used and to check whether or not due regard has been paid to the epidemiological different ways in which the disease spreads through the population. As building an epidemiological model that aspects, statistical is reliable enough and suits the current epidemiological situation within a country or region, certain criteria recommendations, must be met in the modelling process. It might be necessary to use a combination of two or more different model quality types of models in order to cover all aspects of epidemic modelling. If we want epidemiological models to be a useful tool in combating the epidemic, we need to engage experts from epidemiology, data science and statistics. IZVLECEK Izvlecek: Matematicno modeliranje je lahko koristno za napovedovanje razvoja nalezljivih bolezni, saj s prikazom možnih izidov epidemije pomaga oblikovati javnozdravstvene ukrepe. Za napovedovanje in simulacijo Kljucne besede: širjenja v casu epidemije COVID-19 so bile uporabljene razlicne tehnike modeliranja, vendar vse niso bile vedno koristne za epidemiologe in odlocevalce. Da bi bili rezultati modeliranja zanesljivejši, je zelo pomembno kriticno modeliranje COVID-19, ovrednotiti uporabljene podatke ter preveriti, ali so bili upoštevani razlicni nacini širjenja bolezni v populaciji epidemiološki pogled ali ne. Izdelava dobrega epidemiološkega modela, ki je dovolj zanesljiv in ustreza trenutnim epidemiološkim na modeliranje, razmeram v državi ali regiji, je zahtevna, zato je treba pri modeliranju slediti dolocenim kriterijem. Smiselno priporocene bi bilo tudi kombinirati dve razlicni vrsti modelov. Modeliranje bi bilo tako zanesljivejše, saj bi upoštevalo statisticne metode, razlicne predpostavke. Ce želimo, da bodo epidemiološki modeli koristno orodje v boju proti epidemiji, morajo kakovost modelov pri modeliranju sodelovati strokovnjaki z razlicnih podrocij, predvsem epidemiologije, podatkovne znanosti in statistike. *Corresponding author: Tel. + 386 1 300 11 76; E-mail: janez.zibert@zf.uni-lj.si © Nacionalni inštitut za javno zdravje, Slovenija. 1 INTRODUCTION The mathematical modelling of an infectious disease can provide an important insight into the stage of an epidemic and its evolution (1, 2). This can help decision-makers to estimate the impact of various intervention strategies. As the COVID-19 epidemic spread, modelling flourished, with experts from different professional backgrounds using a variety of modelling techniques to predict or simulate the epidemic. However, as we have seen, their predictions have not always been useful to epidemiologists and decision-makers in their efforts to combat the epidemic. Indeed, model outputs have frequently been misused to provide sensational news stories that have greatly frightened the public. Mathematical epidemiological models can be divided into phenomenological, compartmental and individual-based models (1-4). Phenomenological models are data-driven statistical models that use regression analysis, often fitting epidemiological data to exponential or sub-exponential growth observed in the early stages of an epidemic (1). The other two groups of models exploit the insights of the epidemiological dynamics, such as the baseline transmission characteristics of specific pathogens and social contexts. In compartmental models, the population is divided into distinct groups or compartments. For example, in the SIR model (4, 5), these compartments are “susceptible”, “infectious” and “recovered”. While compartmental models usually assume the homogeneous mixing of the population, individual-based models mimic the social network of the population in more detail, for example by incorporating the epidemiological properties of individuals or groups of individuals and their interactions into dynamical networks (6, 7). 2 EPIDEMIOLOGICAL ASPECTS OF MODELLING A particular challenge of epidemiological modelling is that there are many interventions in the context of an epidemic whose common purpose is to change the rate of spread of the infection. This has an impact on exposure of the population, which means that the course of the epidemic is usually different than that predicted by the models before the intervention. Data from the new epidemic situation should therefore be used. Proper communication and explanation of the new situation to the decision-makers, as well as to the general population, is of the utmost importance. In the case of COVID-19, the introduction of measures that aimed to slow down or even stop the spread of infection caused a great deal of uncertainty regarding prediction of the further development of the epidemic. Moreover, the course of the infection is not yet fully understood, meaning that it is not possible to assess the impact of an individual measure on the course of the epidemic. One of the major challenges in modelling epidemics is that the data relies on those who are, in some way, in contact with the healthcare system. The evaluation of the epidemiological situation and the estimation of further development is influenced by the number of people tested, hospitalised and undergoing treatment in intensive care units. If there is unequal access to healthcare for different groups of the population (which is usually the case), modelling predictions can be misleading. Again, it is very important to critically evaluate the data in order to understand the results yielded by an individual model in a specific region. If the development of an epidemic is to be predicted, an assessment of the number of infected people in the population needs to be carried out. In the case of COVID-19, this could only be done by extrapolating the number of infected people from the number of deaths and the number of patients in intensive care and in hospital. However, this approach is only appropriate if the occurrence of cases in the population is homogeneous. This is usually not the case. We have seen that many people who became seriously ill from COVID-19 came from closed communities such as hospitals, nursing homes and similar. These people do not represent the whole population, and models that rely on the numbers of affected people from those communities are not accurate for the whole population. Clusters of the disease, which is a characteristic of COVID-19 as well, greatly affects the number of patients. However, from the point of view of the potential spread of the disease in the population, clusters are less risky than in cases of the diffuse occurrence of infected people among the population, where the potential for spread is much greater. If the model predictions are to be interpreted properly, it is important to consider whether or not these different ways in which the disease spreads through the population are being taken into account (6, 7). 3 RECOMMENDATIONS FOR RELIABLE EPIDEMIOLOGICAL MODELS While, generally speaking, the basic epidemiological models are not too demanding to implement or adopt from the literature (1–7) or available software sources, for the above reasons it is a hard task to build an epidemiological model that is reliable enough and suits the current epidemiological situation within a country or region. When building such a model, the following issues should be considered: • Data should be derived from reliable, frequently updated sources. • Data should be delivered in a timely fashion and should be as “deep” as possible, i.e. not just an aggregation of data over a day or across a region, but rather anonymised individual-based data. • The modelling should take into account the different possibilities of spread among the population locally and among different groups of the population. • The model should assume the non-homogeneous mixing of population. • The dynamics of the disease should be included in the building process and should not rely solely on past data. • The model must consider assumptions that are in line with the epidemiological state of the disease and/ or are estimated from the studies or epidemiological findings of the disease, e.g. parameters such as incubation period, infectious time, time to recover, time in hospital, time in ICU, percentages of hospital care, percentages of ICU, etc. should be estimated from the epidemiological state of the disease and properly incorporated into the model. • The model must satisfy minimal statistical standards such as: • evaluation of the model on real data; • construction of the model using standard statistical methodology; • equipping of the output results with confidence intervals. • The model should be updated frequently to take account of new insights and new data, which results in more reliable predictions of the future occurrence of the disease. • The model should be in line with other epidemiological models with the same properties, or should include explanations of why this is not so. • The model should have publicly available source code and/or explanations of each step of the process. The model should also be ready to simulate different scenarios of the dynamics of the disease from the present situation to the (near) future. It might be also necessary to use a combination of two or more different types of model: phenomenological (1) and/ or compartmental models (4, 5) to obtain an overview and understanding of the epidemiological dynamics, and individual-based models (6, 7) to take into account the non-homogeneous mixing of the population, i.e., different ways of spreading the disease locally and among different groups of the population. If a reliable epidemiological model is to be built, it is therefore important to review and use the already developed and available methodology (1-4) and models (5­7) that address the above issues properly. 4 CONCLUSION Within the large community working on more or less sophisticated mathematical modelling of COVID-19, only some follow the recommended statistical methodology and are suited to the epidemiological situation in individual countries or regions. Some of the models are already being used by decision-makers to track the dynamics of the disease or to estimate the impact of intervention strategies. We strongly believe that epidemiological models that can be used to combat the epidemic need to engage experts from epidemiology, data science and statistics. CONFLICTS OF INTEREST The authors declare that no conflicts of interest exist. FUNDING There was no funding. ETHICAL APPROVAL This paper does not report on any study so ethical approval was not acquired. REFERENCES 1. Chowell G, Sattenspiel L, Bansal S, Viboud C. Mathematical models to characterize early epidemic growth: a review. Physics Life Rev. 2016;18:66-97. doi: 10.1016/j.plrev.2016.07.005. 2. Li MY. An introduction to mathematical modeling of infectious diseases. Cham: Springer, 2018. 3. Vynnycky E, White R. An introduction to infectious disease modelling. Oxford: University Press, 2010. 4. Keeling M, Rohani P. Modeling infectious diseases in humans and animals. Princeton: University Press, 2008. doi: 10.2307/j.ctvcm4gk0. 5. Dadlani A, Afolabi RO, Jung H, Sohraby K, Kim K. Deterministic models in epidemiology: from modeling to implementation. Tech-nical report. Gwangju: Institute of Science and Technology, Communications and Sensor Networks Laboratory, 2013. arXiv preprint arXiv. 2004.04675. 2020. 6. Enright J, Kao RR. Epidemics on dynamic networks. Epidemics. 2018;24:88-97. doi: 10.1016/j.epidem.2018.04.003. 7. Kang H, Liu K, Fu X. Dynamics of an epidemic model with quarantine on scale-free networks. Physics Lett A. 2017;381:3945-51. doi: 10.1016/j.physleta.2017.09.040. SLOVENIAN CROSS-CULTURAL ADAPTATION AND VALIDATION OF HEALTH-RELATED QUALITY OF LIFE MEASURES FOR CHRONIC OTITIS MEDIA (COMQ-12), VERTIGO (DHI, NVI) AND TINNITUS (THI) MEDKULTURNA PRILAGODITEV IN POTRDITEV SLOVENSKIH RAZLICIC VPRAŠALNIKOV ZA OCENO KRONICNEGA VNETJA SREDNJEGA UŠESA (COMQ-12), VRTOGLAVICE (DHI, NVI) IN TINITUSA (THI) Domen VOZEL1,2, Nejc STEINER1, Nina BOŽANIC URBANCIC1,2, Dejan MLADENOV3, Saba BATTELINO1,2* 1University Medical Centre Ljubljana, Department of Otorhinolaryngology and Cervicofacial Surgery, Zaloška 2, 1000 Ljubljana, Slovenia 2University of Ljubljana, Faculty of Medicine, Department of Otorhinolaringology, Vrazov trg 2, 1000 Ljubljana, Slovenia 3Železniški zdravstveni dom Ljubljana, Celovška cesta 4, 1000 Ljubljana, Slovenia Received: Jan 20, 2020 Original scientific article Accepted: Apr 2, 2020 ABSTRACT Purpose: To provide physicians and patients with the tools needed to evaluate patients’ problems and health-related quality of life by cross-culturally adapting and validating the Chronic Otitis Media Questionnaire 12 (COMQ-12), the Keywords: Dizziness Handicap Inventory (DHI), the Neuropsychological Vertigo Inventory (NVI) and the Tinnitus Handicap Inventory (THI). quality of life, surveys and Materials and methods: COMQ-12, DHI, NVI and THI were translated into the Slovenian language and completed by questionnaires, patients treated at our department for chronic otitis media, vertigo or tinnitus. The control group for each questionnaire tinnitus, vertigo, consisted of healthy volunteers. Internal consistency, test-retest reliability, discriminant validity, diagnostic accuracy otitis media, and cut-off value were determined for each questionnaire. dizziness Results: Test-retest reliability was excellent for DHI (ICC A=0.946) and NVI (p=0.315, ICC A=0.975), good to excellent for COMQ-12 (p=0.680, ICC A=0.858) and satisfactory for THI (p=0.120). Discriminant validity was confirmed for each questionnaire (p>0.05) using the Mann-Whitney U test (COMQ-12, DHI, THI) or the Welch t-test (NVI). COMQ-12 had acceptable (a=0.796) and DHI (a=0.910), NVI (a=0.950) and THI (a=0.924) perfect internal consistency. COMQ-12 and DHI had excellent, NVI acceptable and THI perfect diagnostic accuracy (AUC=0.987, AUC=0.999, AUC=0.781 and AUC=1.000 respectively). Cut-off values determined by Youden’s index were 7, 7, 9 and 56 for COMQ-12, THI, DHI and NVI, respectively. Conclusion: Slovenian COMQ-12, DHI, NVI and THI are a valid and accurate tool for the diagnosis and measurement of health-related quality of life in patients with chronic otitis media, vertigo and tinnitus. They could aid general practitioners, occupational health specialists, neurologists and otorhinolaryngologists. IZVLECEK Namen: Orodja za oceno težav bolnikov s kronicnimi vnetji srednjega ušesa, težav z ravnotežjem in tinitusom ter vpliv slednjih na kakovost življenja v slovenšcini ne obstajajo. S projektom smo jih želeli zagotoviti zdravnikom in bolnikom s temi težavami. Vrzel bi zapolnili z medkulturno prilagoditvijo in potrditvijo vprašalnika o kronicnem vnetju srednjega ušesa (COMQ-12), vrtoglavici (DHI), nevropsiholoških vplivih vrtoglavice (NVI) in o obremenjenosti zaradi tinitusa (THI). Kljucne besede: kakovost življenja, ankete in vprašalnik, Metode: Vprašalniki so bili prevedeni iz anglešcine v slovenšcino skladno s priporocili. COMQ-12 so izpolnili bolniki s tinitus, vrtoglavica, kronicnim vnetjem srednjega ušesa, DHI in NVI z vrtoglavico in THI s tinitusom. Kontrolno skupino za vsak vprašalnik vnetje srednjega so sestavljali zdravi prostovoljci. Vsakemu vprašalniku je bila dolocena stopnja notranje skladnosti, zanesljivost pri ušesa, nestabilnost ponovnem testiranju, diskriminantna validnost, diagnosticna natancnost in mejna vrednost. Rezultati: Zanesljivost pri ponovnem testiranju je bila odlicna za DHI (ICCA = 0,946) in NVI (p = 0,315, ICCA = 0,975), dobra do odlicna za COMQ-12 (p = 0,680, ICCA = 0,858) in zadovoljiva za THI (p = 0,120). Diskriminantna validnost je bila potrjena (p > 0,05) za vsak vprašalnik bodisi z uporabo testa Mann-Whitney U (COMQ-12, DHI, THI) bodisi z Welchovim t-testom (NVI). COMQ-12 je imel sprejemljivo (a = 796), DHI (a = 0,910), NVI (a = 0,950) in THI (a = 0,924) pa popolno notranjo skladnost. COMQ-12 in DHI sta imela odlicno (0,987 in 0,999), NVI sprejemljivo (0,781) in THI popolno (1,000) diagnosticno natancnost glede na vrednost površine pod krivuljo ROC. Mejne vrednosti so bile dolocene objektivno z Youdonovim indeksom (J) in so znašale 7 za COMQ-12 (J = 0,90) in THI (J = 1,00), 9 za DHI (J = 0,95) in 56 za NVI (J = 0,43). Zakljucek: Slovenske razlicice vprašalnikov COMQ-12, DHI, NVI in THI so medkulturno prilagojene, potrjene in uporabne kot pomembna merila za oceno z zdravjem povezane kakovosti življenja. Hkrati so tudi natancen diagnosticni pripomocek pri bolnikih s kronicnim vnetjem srednjega ušesa, vrtoglavico ali tinitusom, ki bo v pomoc zdravnikom specialistom družinske medicine, specialistom medicine dela, prometa in športa, nevrologom ter otorinolaringologom. *Corresponding author: Tel. + 386 1 522 83 07; E-mail: saba.battelino@kclj.si © National Institute of Public Health, Slovenia. 1 INTRODUCTION Patient-reported health-related quality-of-life (HRQoL) questionnaires are an indispensable tool for general practitioners, occupational health specialists and physicians of other medical specialisations when approaching a variety of medical conditions. They provide subjective information about the patient’s health status, and complement the objective findings of clinical examination or diagnostic procedures (1-3). They also play an important role in assessing treatment efficacy in many otorhinolaryngologic diseases (4). Chronic otitis media (COM), dizziness and tinnitus are common diseases and symptoms that can have a great impact on HRQoL. Different questionnaires are therefore available in various languages to assess it. Moreover, as there is a common overlap of COM, dizziness and tinnitus-associated complaints in a single patient, it is appropriate to provide multiple questionnaires to assess these complaints. COMQ-12, DHI, NVI and THI are useful questionnaires to determine physical, cognitive, socio­ economic and emotional neuropsychological influences of the disease on HRQoL (5-8). When modifying a questionnaire from an original to the desired target language, a thorough process of cross-cultural adaptation and validation is required, rather than a simple translation (9). It appears that this process may present a certain obstacle as, to the best of our knowledge, no such questionnaires for patients with COM, dizziness and tinnitus have yet been produced in the Slovenian language. There is therefore a desire to provide such questionnaires to physicians dealing with patients with COM, dizziness and tinnitus in Slovenia. For that reason, the purpose of our study was to cross-culturally adapt and validate Chronic Otitis Media Questionnaire 12 (COMQ-12), the Dizziness Handicap Inventory (DHI), the Neuropsychological Vertigo Inventory (NVI) and the Tinnitus Handicap Inventory (THI) into the Slovenian language for the first time. Furthermore, Slovenian versions of COMQ-12, DHI, NVI and THI would contribute to a further comparison of populations divided by culture or language. 1.1 Chronic Otitis Media COM can be defined as at least three months of persistent middle ear inflammation with an associated permanent tympanic membrane defect. While inconsistent definitions of COM make the analysis of epidemiological data difficult, assessments of the burden presented by otitis media have been made. It is a leading reason why patients visit a doctor and are prescribed medication, and it places the brunt of the burden on developing countries (10). In some countries, the cost of treating ear infections is higher than the minimum monthly wage (11). The population of developed industrialised countries, including Slovenia, is the least at risk (10). COM causes disabling hearing loss, impedes speech development and involvement in education, and makes it more difficult to find and retain employment in jobs that require high levels of qualification (12). Additionally, patients with COM are affected by ear discharge, ear discomfort, balance disorders, tinnitus and mental disorders, all of which lead to poorer quality of life and higher levels of absenteeism (13, 14). HRQoL patient- reported questionnaires are therefore an important adjunct to the management of patients with COM (5). 1.2 COMQ-12 At least five patient-reported HRQoL questionnaires are available to assess the quality of life of COM patients. COMQ-12, and ZCMEI-21 are upgrades of CES, COMOT-15, COM-5. COMQ-12 is shorter than ZCMEI-21 (14, 15). Chronic Otitis Media Questionnaire 12 (COMQ-12) contains 12 questions: seven related to the severity of symptoms, two to the impact of the disease on lifestyle, two to the impact on healthcare and one general question. Each answer is given a score of 0-5 points (14). A total score is also determined for persons without COM. Additionally, if the total score is =5, surgical treatment should be reconsidered (16). The original English version has so far been translated into Turkish (5), Portuguese (17), Indian (18), Serbian (19) and Dutch (20, 21), etc. 1.3 Vertigo Vertigo is defined as the perception of rotation or movement of an individual or objects in space. Patients often confuse it with symptoms of dizziness or visual or balance disturbance (7). In addition to the normal functioning of the vestibular apparatus, normal balance requires good vision and proprioception and good functioning of the central nervous system, which is where the integration of signals from these systems takes place. Damage to any of these structures can cause vertigo. Dizziness, impaired balance, vision, emotions, memory and self-perception may be associated with vertigo depending on the location of the dysfunction of the vestibular system. Understandably, patients often experience vertigo, dizziness and unsteadiness at the same time (rarely each of these symptoms individually). About 50% of people experience vertigo, 40% unsteadiness and 35% dizziness in one year (22). Vertigo and dizziness are also risk factors for falls, especially in the elderly (23). These problems lead to loss of an employment in 20% and reduction of work efficiency and social life impairment in 50% of cases (24). Vertigo and dizziness can therefore severely reduce quality of life and represent a major public health problem. For that reason, it is crucial to evaluate a patient’s problems by means of patient-reported HRQoL questionnaires. 1.4 DHI The DHI is a reference questionnaire (25) most commonly used to evaluate vertigo-associated problems (7). It has been developed to evaluate problems with balance, since the results of vestibulometry (e.g. caloric test) are often inconsistent with the clinical findings (26, 27). The DHI consists of 25 questions, 7 of which are related to physical, 9 to emotional and 9 to the functional influences of vertigo. The patient answers each question with “yes” (4 points), “sometimes” (2 points) or “no” (0 points). A higher total score means that vertigo has a more severe impact on the patient’s quality of life. Four questions directly evaluate issues specific to the problems associated with benign paroxysmal positional vertigo (27). DHI has been translated into Swedish (28), Chinese (29), Dutch (30), Turkish (31), Italian (32), German (33), Spanish (34), Greek (6), etc. 1.5 NVI The NVI was developed in response to the absence of questionnaires that evaluate vertigo-related cognitive problems. It tests attention, memory, emotion, vision, motor skills, and spatial and time perception. It is therefore designed to assess patient-reported, vertigo-associated neuropsychological problems. The NVI has so far been made available in English and French (35). The French version consists of 28 and the English of 32 questions, containing 4 distractors (7, 35). The answer to each question is scored using the Likert scale (7). The English version without distractors was used to cross-culturally adapt and validate the Slovenian NVI. 1.6 Tinnitus Tinnitus is the perception of sound without a known external stimulus (36). In 8-17% of people, it occurs as temporary simple ringing after exposure to noise and it is rarely permanent (37). Its incidence increases with age and is present in 15% of people over the age of 65 (36, 37). In most cases, people do not seek medical attention because of tinnitus, as it does not significantly impact their daily life. However, it does have a significant impact on quality of life in some (36), and leads to hyperacusis, impaired cognitive ability, anhedonia, anxiety, depression and insomnia. Suicidality resulting from severe tinnitus has also been reported (37). Tinnitus can therefore interfere with daily activities (38) and affects the quality of life of certain personality types more significantly (38). The degree of tinnitus impairment also depends on tinnitus awareness throughout the day, the loudness and variability of the tinnitus, education, and additional physical symptoms (39). Although tinnitus can be determined audiometrically, patient-reported HRQoL questionnaires present an indispensable tool for evaluating tinnitus (40, 41). 1.7 THI The THI is useful for evaluating tinnitus and its impact on HRQoL. It comprises 25 questions and is expected to complement the DHI in clinical practice. Twelve questions evaluate functional, eight emotional and five catastrophic responses to tinnitus. The patient answers each question with “yes” (4 points), “sometimes” (2 points) or “no” (0 points), where the maximum score is 100. Scoring 78–100 points means that the tinnitus is catastrophic, 58–76 severe, 38-56 moderate, 18-36 mild and <18 light (42). The THI has been translated into Hungarian (43), Danish (44), Polish (45), Korean (46), Brazilian Portuguese (47), Turkish (48), Italian (49), Chinese (50, 51), French (52, 53), Hebrew (54), Russian (8), etc. 2 MATERIALS AND METHODS 2.1 Translation and Cross-Cultural Adaptation of Questionnaires To enable replicability, the cross-cultural adaptation and validation processes are described according to the guidelines for translating and adapting hearing-related questionnaires for different languages and cultures by Hall et al. (9). We conducted an initial review of the literature and were unable to locate any Slovenian versions of the COMQ-12, DHI, NVI or THI questionnaires. Permission to use the questionnaires was obtained from the authors of the original questionnaires. These authors were available for any additional questions regarding concepts or ambiguities behind the items. Literacy, population characteristics and the requirement for administrative help were evaluated for the target population. Template documents for recording the translation and adaptation process were created and the definition of concepts for each questionnaire item developed. Two independent dual-language translators (native Slovenian speakers with a very good knowledge of English) were briefed on the questionnaires and their clinical concepts. They independently translated questionnaires into Slovenian (i.e. forward translation). The two translations were harmonised by two field experts to create a single translation. Two independent dual-language translators (native English speakers with a very good knowledge of Slovenian) then independently translated the questionnaires back to the English language (i.e. back-translation). The two translations were reconciled by two field experts to create a single translation, which was then reviewed by the board of experts (one otosurgeon, one audiologist, two general otorhinolaryngology consultants, two otorhinolaryngology residents, one non-medical translation consultant). This was followed by pilot testing with the target audience (20 patients for each questionnaire) to ensure that the questions were understood and culturally appropriate. The results of the pilot testing were reviewed and the translation finalised. The same board of experts formatted and proofread the finalised translation. The questionnaires were then given to patients with COM, dizziness or tinnitus and to healthy volunteers. These subjects were later included in the statistical analysis. 2.2 Subjects Patients treated at our department for COM, vertigo or tinnitus completed the COMQ-12, DHI, NVI or THI after an otorhinolaryngological check-up and confirmation of the diagnosis. The control groups for each questionnaire consisted of healthy volunteers, i.e. medical staff and their acquaintances or relatives. Every subject gave informed consent. 2.3 Statistical Analysis After the cross-cultural adaptation of all the questionnaires, the validation was performed using various statistical methods; these are thoroughly described in order to enable replicability. Data were analysed using Microsoft Excel for Mac (version 16 and later) and SPSS (Statistical Package for the Social Sciences, version 23, IBM Corp., Armonk, NY, USA). Internal consistency, test-retest reliability, discriminant validity, diagnostic accuracy and cut-off value were determined for each questionnaire. Internal consistency was determined with Cronbach’s alpha and diagnostic accuracy and cut-off values using ROC curve analysis and Youden’s index (55). Test-retest reliabilities and discriminant validities were determined by means of various statistical tests and depending on the analysed data. 3 RESULTS The Slovenian translations of the COMQ-12, DHI, NVI and THI are available from the authors upon request and from the institution’s official website. 3.1 COMQ-12 COMQ-12 was completed by 20 (52.6%) male and 18 (47.7%) female patients (P) with an average age of COMQ-12 52.02±16.61 years (Mdn=55 years, Ra=18–87 years) and average score of 23.34±10.47 (Mdn=22, Ra=4-51). The control group that completed COMQ-12 consisted of 10 (16.4%) male and 51 (83.6%) female volunteers with an average age of 37±10.53 years (Mdn=35 years, Ra=41 years). They completed COMQ-12 twice within a two-day interval, hence test (CT) and retest (CRT). The COMQ-12COMQ-12 average score was 1.410±3.111 (Mdn=0, Ra=20) for CT COMQ-12 and 1.246±2.248 (Mdn=0, Ra=9) for CRT COMQ-12. 3.2 DHI and NVI The DHI and NVI were each completed twice within a three- day interval by identical groups comprising 26 (43.3%) male and 34 (56.7%) female patients with an average age of 61.4±13.8 years (Mdn=63.5 years, Ra=56 years). The average score was 49.67±22.843 (Mdn=52, Ra=86) for first completion of the DHI (PTDHI) and 47.00±22.81 (Mdn=49, Ra=84) for the second completion (PRTDHI). The average score was 65.07±18.78 (Mdn=65, Ra=80) for first completion of the NVI (PTNVI) and 64.52±18.88 (Mdn=65, Ra=80) for the second completion (PRTNVI). The DHI and NVI were completed by identical control groups comprising 28 (46.7%) male and 32 (53.5%) female volunteers with an average age of 46.6±16.2 years (Mdn=45 years, Ra=51 years). The average score was 1.17±2.395 (Mdn=0, Ra=10) for the DHI control group (CDHI) and 47.68±18.88 (Mdn=65, Ra=80) for the NVI control group (CNVI). 3.3 THI The THI was completed by 19 (31.7%) male and 41 (68.3%) female patients (PTHI) with an average age of 53.80±13.7 years (Mdn=57 years, Ra=59 years) and an average score of 52.12±23.50 (Mdn=51, Ra=88). The control group completed the THI twice over an interval of a few days. The THI was first completed by 19 (31.7%) male and 41 (68.3%) female volunteers with an average age of 37±10.53 years (Mdn=35 years, Ra=41 years) as a test group (CTTHI). The retest group (CRTTHI) consisted of three male (23.1%) and ten female (76.9%) volunteers recruited from the CTTHI with an average age of 47.4±13.5 years (Mdn=49 years, Ra=52 years) and average score of 0±0 (Mdn=0, Ra=0). 3.4 Statistical Analysis Test-retest reliability, discriminant validity, internal consistency, ROC curve analysis and cut-off value for each questionnaire are depicted in Table 1 and Figures 1, 2 and 3. Table 1. Test-retest reliability, discriminant validity, internal consistency, cut-off value and Youden’s index for the COMQ-12, DHI, NVI and THI. Test-retest reliability Discriminant a AROC Cut-off J validity value COMQ-12 p=0.680*, ICCA=0.858 (0.774–0.912)** p<0.0005 † 0.796 0.987 7 0.90 DHI ICCA=0.946 p<0.0005 † 0.910 0.999 9 0.95 (0.902–0.969)** NVI p=0.315‡, ICCA=0.975 (0.959–0.985)** p<0.0005 ‡‡ 0.950 0.781 56 0.43 THI p=0.120* p<0.0005 † 0.924 1.000 7 1.00 Legend: a, Cronbach’s alpha; AROC, area under ROC curve; J, Youden’s index; p, p-value; *, Wilcoxon signed-rank test; **, type A intraclass correlation coefficient estimates and their 95% confident intervals using an absolute agreement definition, based on single measures and two-way mixed effects (ICCA); †, Mann-Whitney U test using an exact sampling distribution for U (Dineen & Blakesley, 1973); ‡, paired samples t-test; ‡‡, Welch’s t-test. Commentary: statistical significance is p<0.05. As the minimum NVI score is 28, the cut-off value is higher compared to the other questionnaires. Figure 2. DHI ROC curve. Figure 1. COMQ-12 ROC curve. Figure 3. NVI ROC curve. 4 DISCUSSION Each questionnaire had satisfactory test-retest reliability as determined by the intraclass correlation coefficient, the paired samples t-test or the Wilcoxon signed-rank test. Furthermore, the Slovenian COMQ-12 had good-to­excellent test-retest reliability, which was better than has been reported recently (18, 56). The Slovenian DHI had excellent test-retest reliability based on the intraclass correlation coefficient. This is consistent with other studies (32, 56). Since the NVI has only recently been developed, to the best of our knowledge no studies have yet been published regarding its test-retest reliability (35, 57). Instead, the Slovenian NVI possesses excellent test-retest reliability and contributes significantly to the current literature. As in other studies, the discriminant validity was confirmed for the Slovenian COMQ-12, DHI and THI using the Mann-Whitney U test and for the Slovenian NVI using Welch t-test by determining p>0.05 (5, 7, 53). According to Cronbach’s alpha, the Slovenian DHI, NVI and THI had perfect internal consistency, even higher compared to other studies (7, 8, 32). The Slovenian COMQ­12 had acceptable internal consistency. To evaluate diagnostic accuracy and the cut-off value, the area under the ROC curve (AROC) and Youden’s index were determined for each questionnaire. The Slovenian Figure 4. THI ROC curve. COMQ-12 and DHI had excellent, NVI acceptable and THI perfect diagnostic accuracies according to AROC (58). There is no similar data published for DHI, NVI and THI in other languages regarding diagnostic accuracy and cut-off values by determining AROC and Youden’s index. 5 CONCLUSION The COMQ-12, DHI, NVI and THI questionnaires were cross-culturally adapted and validated in the Slovenian language for the first time. The questionnaires can be used in diagnosis or for evaluating the treatment outcome. It is therefore an efficient and essential tool for the comprehensive management of patients with chronic otitis media, dizziness and tinnitus. They are useful for general practitioners, occupational health specialists, neurologists and otorhinolaryngologists. In the future, the COMQ-12, DHI, NVI and THI questionnaires could also assist a physician in their choice of the most appropriate treatment modality, via their implementation to disease-management guidelines. However, further research is needed to substantiate the usefulness of these questionnaires for different types of chronic otitis media, vertigo and tinnitus. The relationships between the questionnaires and other diagnostic tests should also be considered. The Slovenian COMQ-12, DHI, NVI and THI could be used in research into new treatment efficacies and into the impact of treatment on a patient’s health-related quality of life. As we live in a digital era, the future lies in electronic questionnaires, which are easier to access and complete and aid the data analysis process. ACKNOWLEDGEMENTS John Phillips, Gary P. Jacobson, Emilia Lacroix and Craig W. Newman for permission to translate the original COMQ­12, DHI, NVI and THI, respectively. CONFLICTS OF INTEREST The authors declare that no conflicts of interest exist. FUNDING There is no financial interest or risk. ETHICAL APPROVALS Received from the Republic of Slovenia National Medical Ethics Committee (Nos 0120-146/2019/5, 0120-032/2016-2 and 21/6/15) REFERENCES 1. Zelko E, Švab I, Pavlic Rotar D. Quality of life and patient satisfaction with family practice care in a Roma population with chronic conditions in northeast Slovenia. Zdr Varst. 2015;54(1):18-26. doi: 10.1515/sjph­ 2015-0003. 2. Štern B, Hojs Fabjan T, Rener-Sitar K, Zaletel-Kragelj L. Validation of the Slovenian version of Multiple Sclerosis Quality of Life (MSQOL-54) instrument. Zdr Varst. 2017;56(4):260-7. doi: 10.1515/sjph-2017-0035. 3. Grosek J, Košir JA, Novak J, Omejc M, Tomažic A, Norcic G. Validation of the Slovenian version of the Low Anterior Resection Syndrome score for rectal cancer patients after surgery. Zdr Varst. 2019;58(4):148-54. doi: 10.2478/sjph-2019-0019. 4. Urbancic J, Soklic Košak T, Jenko K, Božanic Urbancic N, Hudoklin P, Delakorda M, et al. Cross-cultural adaptation and validation of Nasal Obstruction Symptom Evaluation questionnaire in Slovenian language. Zdr Varst. 2016;56(1):18-23. doi: 10.1515/sjph-2017-0003. 5. Doruk C, Çelik M, Kara H, Polat B, Güldiken Y, Orhan KS. Turkish translation and validation of Chronic Otitis Media Questionnaire-12. Turk Arch Otorhinolaryngol. 2019;57(1):24-9. doi: 10.5152/ tao.2019.3693. 6. Nikitas C, Kikidis D, Katsinis S, Kyrodimos E, Bibas A. Translation and validation of the Dizziness Handicap Inventory in Greek language. Int J Audiol. 2017;56(12):936941. doi: 10.1080/14992027.2017.1370559. 7. Lacroix E, Deggouj N, Salvaggio S, Wiener V, Debue M, Edwards MG. The development of a new questionnaire for cognitive complaints in vertigo: the Neuropsychological Vertigo Inventory (NVI). Eur Arch Otorhinolaryngol. 2016;273(12):4241-9. doi: 10.1007/s00405-016­4135-x. 8. Oron Y, Sergeeva NV, Kazlak M, Barbalat I, Spevak S, Lopatin AS, et al. A Russian adaptation of the Tinnitus Handicap Inventory. Int J Audiol. 2015;54(7):485-9. doi: 10.3109/14992027.2014.996823. Zdr Varst. 2020;59(3):120-127 9. Hall DA, Domingo SZ, Hamdache LZ, Manchaiah V, Thammaiah S, Evans C, et al. A good practice guide for translating and adapting hearing-related questionnaires for different languages and cultures. Int J Audiol. 2018;57(3):161-75. doi: 10.1080/14992027.2017.1393565. 10. Monasta L, Ronfani L, Marchetti F, Montico M, Vecchi Brumatti L, Bavcar A, et al. Burden of disease caused by otitis media: systematic review and global estimates. PLoS One. 2012;7(4):e36226. doi: 10.1371/ journal.pone.0036226. 11. Adoga A, Nimkur T, Silas O. Chronic suppurative otitis media: socio­economic implications in a tertiary hospital in Northern Nigeria. Pan Afr Med J. 2010;4(3). doi: 10.11604/pamj.26/01/2010 .4.3.158. 12. Maile EJ, Youngs R. Quality of life measures in otitis media. J Laryngol Otol. 2013;127(5):442-7. doi: 10.1017/S0022215113000509. 13. Bakir S, Kinis V, Bez Y, Gun R, Yorgancilar E, Ozbay M, et al. Mental health and quality of life in patients with chronic otitis media. Eur Arch Otorhinolaryngol. 2013;270(2):521-6. doi: 10.1007/s00405-012­ 2031-6. 14. Phillips JS, Haggard M, Yung M. A new health-telated quality of life measure for active chronic otitis media (COMQ-12): development and initial validation. Otol Neurotol. 2014;35(3):454-8. doi: 10.1097/ MAO.0000000000000205. 15. Bächinger D, Röösli C, Ditzen B, Huber AM. Development and validation of the Zurich chronic middle ear inventory (ZCMEI-21): an electronic questionnaire for assessing quality of life in patients with chronic otitis media. Eur Arch Otorhinolaryngol. 2016;273(10):3073-81. doi: 10.1007/s00405-016-3915-7. 16. Phillips JS, Yung MW. COMQ-12 scores in adult patients without chronic middle ear disease. Clin Otolaryngol. 2014;39(6):362-7. doi: 10.1111/ coa.12306. 17. Fonseca ACO, Ramos P, Balsalobre FA, Freitas E, Phillips JS, Yung MW, et al. Validation of a Portuguese version of the health-related quality of life measure for active chronic otitis media (COMQ-12). Braz J Otorhinolaryngol. 2018;84(6):708-12. doi: 10.1016/j.bjorl.2017.08.007. 18. Prabhu P, Chandrashekar A, Jose A, Ganeshan A, Kiruthika L. Development and administration of chronic suppurative otitis media questionnaire-12 (COMQ-12) and Chronic Otitis Media Outcome Test-15 (COMOT-15) in Kannada. Int Arch Otorhinolaryngol. 2018;22(02):108­ 12. doi: 10.1055/s-0037-1603644. 19. Bukurov B, Arsovic N, Grujicic SS, Haggard M, Spencer H, Marinkovic JE. Psychometric characteristics of the Chronic Otitis Media Questionnaire 12 (COMQ-12): stability of factor structure and replicability shown by the Serbian version. Health Qual Life Outcomes. 2017;15(207). doi: 10.1186/s12955-017-0782-x. 20. Oorts E, Phillips JS, Van de Heyning P, Yung M, Van Rompaey V. Dutch health-related quality of life measure for chronic otitis media. B-ENT. 2015;11(4):291-5. 21. van Dinther J, Droessaert V, Camp S, Vanspauwen R, Maryn Y, Zarowski A, et al. Validity and test-retest reliability of the Dutch version of the Chronic Otitis Media Questionnaire 12 (COMQ-12). J Int Adv Otol. 2015;11(3):248-52. doi: 10.5152/Iao.2015.1701. 22. Bisdorff A, Bosser G, Gueguen R, Perrin P. The epidemiology of vertigo, dizziness, and unsteadiness and its links to co-morbidities. Front Neurol. 2013;4:29. doi: 10.3389/fneur.2013.00029. 23. Ciorba A, Bianchini C, Scanelli G, Pala M, Zurlo A, Aimoni C. The impact of dizziness on quality-of-life in the elderly. Eur Arch Otorhinolaryngol. 2017;274(3):1245-50. doi: 10.1007/s00405-016-4222-z. 24. Bronstein AM, Golding JF, Gresty MA, Mandalŕ M, Nuti D, Shetye A, et al. The social impact of dizziness in London and Siena. J Neurol. 2010;257(2):183-90. doi: 10.1007/s00415-009-5287-z. 25. Duracinsky M, Mosnier I, Bouccara D, Sterkers O, Chassany O, Working Group of the Société Française d’Oto-Rhino-Laryngologie (ORL). Literature review of questionnaires assessing vertigo and dizziness, and their impact on patients’ quality of life. Value Health. 2007;10(4):273-84. doi: 10.1111/j.1524-4733.2007.00182.x. 26. Yip CW, Strupp M. The Dizziness Handicap Inventory does not correlate with vestibular function tests: a prospective study. J Neurol. 2018;265(5):1210-8. doi: 10.1007/s00415-018-8834-7. 27. Jacobson GP, Newman CW. The development of the Dizziness Handicap Inventory. Arch Otolaryngol Head Neck Surg. 1990;116(4):424-7. doi: 10.1001/archotol.1990.01870040046011. 28. Jarlsäter S, Mattsson E. Test of reliability of the Dizziness Handicap Inventory and the Activities-specific Balance Confidence scale for use in Sweden. Adv Physiother. 2003;5(3):137-44. doi: 10.1080/14038190310004385. 29. Chen W, Shu L, Wang Q, Pan H, Wu J, Fang J, et al. Validation of 5-item and 2-item questionnaires in Chinese version of Dizziness Handicap Inventory for screening objective benign paroxysmal positional vertigo. Neurol Sci. 2016;37(8):1241-6. doi: 10.1007/s10072-016-2573­ 2. 30. Vereeck L, Truijen S, Wuyts F, Van de Heyning PH. Test-retest reliability of the Dutch version of the Dizziness Handicap Inventory. B-ENT. 2006;2(2):75-80. 31. Karapolat H, Eyigor S, Kirazli Y, Celebisoy N, Bilgen C, Kirazli T. Reliability, validity and sensitivity to change of Turkish Dizziness Handicap Inventory (DHI) in patients with unilateral peripheral vestibular disease. J Int Adv Otol. 2009;5:237-45. 32. Colnaghi S, Rezzani C, Gnesi M, Manfrin M, Quaglieri S, Nuti D, et al. Validation of the Italian version of the Dizziness Handicap Inventory, the Situational Vertigo Questionnaire, and the Activity-specific Balance Confidence scale for peripheral and central vestibular symptoms. Front Neurol. 2017;8:528. doi: 10.3389/fneur.2017.00528. 33. Kurre A, van Gool CJAW, Bastiaenen CHG, Gloor-Juzi T, Straumann D, de Bruin ED. Translation, cross-cultural adaptation and reliability of the German version of the Dizziness Handicap Inventory. Otol Neurotol. 2009;30(3):359-67. doi: 10.1097/MAO.0b013e3181977e09. 34. Pérez N, Garmendia I, Martín E, García-Tapia R. Cultural adaptation of 2 questionnaires for health measurement in patients with vertigo. Acta Otorrinolaringol Esp. 2000;51(7):572-80. 35. The Neuropsychological Vertigo Inventory (NVI). Accessed September 23th, 2019 at: http://www.nvi-questionnaire.com/en/. 36. Degeest S, Corthals P, Dhooge I, Keppler H. The impact of tinnitus characteristics and associated variables on tinnitus-related handicap. J Laryngol Otol. 2016;130(1):25-31. doi: 10.1017/S0022215115002716. 37. Moring J, Bowen A, Thomas J, Bira L. The emotional and functional impact of the type of tinnitus sensation. J Clin Psychol Med Settings. 2016;23(3):310-8. doi: 10.1007/s10880-015-9444-5. 38. Bartels H, Pedersen S, Laan B van der, Staal M, Albers F, Middel B. The impact of type D personality on health-related quality of life in tinnitus patients is mainly mediated by anxiety and depression. Otol Neurotol. 2010;31(1):11-8. doi: 10.1097/MAO.0b013e3181bc3dd1. 39. Hoekstra CEL, Wesdorp FM, van Zanten GA. Socio-demographic, health, and tinnitus related variables affecting tinnitus severity. Ear Hear. 2014;35(5):544-54. doi: 10.1097/AUD.0000000000000045. 40. Skarzynski PH, Rajchel JJ, Gos E, Dziendziel B, Kutyba J, Bienkowska K, et al. A revised grading system for the Tinnitus Handicap Inventory based on a large clinical population. Int J Audiol. 2020;59(1):61-7. doi: 10.1080/14992027.2019.1664778. 41. Ristovska L, Jachova Z, Stojcheska V. Psychoacoustic characteristics of tinnitus in relation to audiometric profile. Arch Acoust. 2019;44(3):419– 28. doi: 10.24425/aoa.2019.129258. 42. Newman CW, Jacobson GP, Spitzer JB. Development of the Tinnitus Handicap Inventory. Arch Otolaryngol Head Neck Surg. 1996;122(2):143­ 8. doi: 10.1001/archotol.1996.01890140029007. 43. Bencsik B, Tamás L, Trimmel K, Stauder A. Hungarian adaptation of the Tinnitus Handicap Inventory: reliability and validity. Eur Arch Otorhinolaryngol. 2015;272(9):2243-8. doi: 10.1007/s00405-014-3138­ 8. 44. Zachariae R, Mirz F, Johansen LV, Andersen SE, Bjerring P, Pedersen CB. Reliability and validity of a Danish adaptation of the Tinnitus Handicap Inventory. Scand Audiol. 2000;29(1):37-43. doi: 10.1080/010503900424589. 45. Wrzosek M, Szymiec E, Klemens W, Kotylo P, Schlee W, Modrzynska M, et al. Polish translation and validation of the Tinnitus Handicap Inventory and the Tinnitus Functional Index. Front Psychol. 2016;7:1871. doi: 10.3389/fpsyg.2016.01871. 46. Jun HJ, Yoo IW, Hwang SJ, Hwang SY. Validation of a Korean version of the tinnitus handicap questionnaire. Clin Exp Otorhinolaryngol. 2015;8(3):198-201. doi: 10.3342/ceo.2015.8.3.198. 47. Schmidt LP, Teixeira VN, Dall’Igna C, Dallagnol D, Smith MM. Brazilian Portuguese language version of the “Tinnitus Handicap Inventory”: validity and reproducibility. Braz J Otorhinolaryngol. 2006;72(6):808­ 10. doi: 10.1016/S1808-8694(15)31048-X. 48. Aksoy S, Firat Y, Alpar R. The Tinnitus Handicap Inventory: a study of validity and reliability. Int Tinnitus J. 2007;13(2):94-8. 49. Monzani D, Genovese E, Marrara A, Gherpelli C, Pingani L, Forghieri M, et al. Validity of the Italian adaptation of the Tinnitus Handicap Inventory; focus on quality of life and psychological distress in tinnitus-sufferers. Acta Otorhinolaryngol Ital. 2008;28(3):126-34. 50. Kam ACS, Cheung APP, Chan PYB, Leung EKS, Wong TKC, van Hasselt CA, et al. Psychometric properties of the Chinese (Cantonese) Tinnitus Handicap Inventory. Clin Otolaryngol. 2009;34(4):309-15. doi: 10.1111/j.1749-4486.2009.01946.x. 51. Meng Z, Zheng Y, Liu S, Wang K, Kong X, Tao Y, et al. Reliability and validity of the Chinese (Mandarin) Tinnitus Handicap Inventory. Clin Exp Otorhinolaryngol. 2012;5(1):10-6. doi: 10.3342/ceo.2012.5.1.10. 52. Ghulyan-Bédikian V, Paolino M, Giorgetti-D’Esclercs F, Paolino F. Psychometric properties of a French adaptation of the Tinnitus Handicap Inventory. Encephale. 2010;36(5):390-6. doi: 10.1016/j. encep.2009.12.007. 53. Bolduc D, Désilets F, Tardif M, Leroux T. Validation of a French (Québec) version of the Tinnitus Handicap Inventory. Int J Audiol. 2014;53(12):903-9. doi: 10.3109/14992027.2014.935495. 54. Oron Y, Shushan S, Kreitler S, Roth Y. A Hebrew adaptation of the Tinnitus Handicap Inventory. Int J Audiol. 2011;50(6):426-30. doi: 10.3109/14992027.2011.561503 55. Ruopp MD, Perkins NJ, Whitcomb BW, Schisterman EF. Youden Index and optimal cut-point estimated from observations affected by a lower limit of detection. Biom J. 2008;50(3):419-30. doi: 10.1002/ bimj.200710415. 56. Koo TK, Li MY. A guideline of selecting and reporting intraclass correlation coefficients for reliability research. J Chiropr Med. 2016;15(2):155-63. doi: 10.1016/j.jcm.2016.02.012. 57. Liu YF, Locklear TD, Sharon JD, Lacroix E, Nguyen SA, Rizk HG. Quantification of Cognitive Dysfunction in Dizzy Patients Using the Neuropsychological Vertigo Inventory. Otol Neurotol. 2019;40(7):e723– 31. doi: 10.1097/MAO.0000000000002311. 58. Mandrekar JN. Receiver operating characteristic curve in diagnostic test assessment. J Thorac Oncol. 2010;5(9):1315-6. doi: 10.1097/ JTO.0b013e3181ec173d. OPTIMISATION OF HEART FAILURE MANAGEMENT IN NURSING HOMES USING POINT-OF-CARE ULTRASONOGRAPHY: HARMONIOUS TRIAL RATIONALE AND DESIGN UPORABA OBPOSTELJNE ULTRASONOGRAFIJE ZA IZBOLJŠANJE VODENJA SRCNEGA POPUŠCANJA V DOMOVIH STAREJŠIH OBCANOV: METODOLOGIJA ŠTUDIJE HARMONIOUS Vesna HOMAR1,2*, Igor ŠVAB1,3, Mitja LAINŠCAK3,4 1University of Ljubljana, Faculty of Medicine, Department of Family Medicine, Poljanski nasip 58, 1000 Ljubljana, Slovenia 2Zdravstveni dom Vrhnika, Cesta 6. maja 11, Vrhnika, Slovenija 3University of Ljubljana, Faculty of Medicine, Vrazov trg 2, 1000 Ljubljana, Slovenia 4General Hospital Murska Sobota, Division of Cardiology, Ulica dr. Vrbnjaka 6, 9000 Murska Sobota, Slovenia Received: Dec 22, 2019 Original scientific article Accepted: May 7, 2020 ABSTRACT Introduction: Heart failure is common in the nursing home population and presents many diagnostic and therapeutic challenges. Point-of-care ultrasonography is a bedside method that can be used to assess volume status more Keywords: reliably than clinical examination. This trial was conceived to test whether point-of-care ultrasonography-guided management improves heart failure outcomes among nursing home residents. nursing homes, heart failure, point-of-care Methods: Nursing home residents with heart failure will be enrolled in a multi-centre, prospective, randomised ultrasonography, controlled trial. Residents will first be screened for heart failure. Patients with heart failure will be randomised volume assessment in 1:1 fashion into two groups. Nursing home physicians will adjust diuretic therapy according to volume status for six months. Point-of-care ultrasonography will be used in the test group and clinical examination in the control group. The primary endpoint will be heart failure deterioration, defined as a composite of any of the following four events: the need for an intravenous diuretic application, the need for an emergency service intervention, the need for unplanned hospitalisation for non-injury causes, or death from whatever cause. Expected results: The expected prevalence of heart failure among nursing home residents is above 10%. Point-of­care ultrasonography-guided heart failure management will reduce the number of deteriorations of heart failure in the nursing home population. Conclusion: This study will explore the usefulness of point-of-care ultrasonography for heart failure management in the nursing home population. IZVLECEK Uvod: Zdravljenje srcnega popušcanja v domovih starejših obcanov ima številne diagnosticne in terapevtske izzive. Obposteljna ultrasonografija je nova metoda, ki omogoca natancnejšo oceno volumske obremenitve kot Kljucne besede: klinicni pregled. Namen te raziskave je preizkusiti, ali lahko z uporabo obposteljne ultrasonografije izboljšamo izide stanovalcev domov starejših obcanov s srcnim popušcanjem. domovi starejših obcanov, srcno Metode: Izvedli bomo multicentricni, prospektivni kontrolirani preizkus, ki bo vkljucil stanovalce domov starejših popušcanje, obcanov s srcnim popušcanjem. Sprva bomo presejali stanovalce domov starejših obcanov glede srcnega popušcanja. obposteljna Paciente s srcnim popušcanjem bomo randomizirali 1 : 1 v dve skupini. Zdravniki v domovih starejših obcanov ultrasonografija, ocena bodo 6 mesecev prilagajali diureticno terapijo glede na volumsko obremenitev – v testni skupini bodo volumsko volumske obremenitve obremenitev ocenjevali z obposteljnim ultrazvokom, v kontrolni skupini le klinicno. Primarni opazovani izid bo poslabšanje srcnega popušcanja, doloceno kot pojav kateregakoli od naštetih dogodkov: potrebe po intravenskem antibiotiku ali potrebe po aktivaciji dežurne službe ali potrebe po neplanirani nepoškodbeni hospitalizaciji ali smrti zaradi kateregakoli razloga. Pricakovani rezultati: Pricakovana prevalenca srcnega popušcanja med stanovalci domov starejših obcanov je vec kot 10-odstotna. Vodenje stanovalcev s srcnim popušcanjem z obposteljno ultrasonografijo bo zmanjšalo število poslabšanj srcnega popušcanja. Zakljucek: Ta raziskava bo raziskala uporabnost obposteljne ultrasonografije pri vodenju bolnikov s srcnim popušcanjem v domovih starejših obcanov. *Corresponding author: Tel. + 386 41 369 765; E-mail: vesna.homar@gmail.com © National Institute of Public Health, Slovenia. 1 INTRODUCTION The nursing home population is specific and challenging from several healthcare perspectives. Most nursing home residents are elderly and have more than one chronic medical condition. Heart failure (HF) is one of the most prevalent chronic conditions. When symptomatic, it affects the health-related quality of life of elderly people (1, 2). Prevalence in those aged 75–84 and >85 years is 9.7 and 17.4% respectively (3, 4) and the prevalence in nursing homes ranges from 15% to 45% (5). HF is associated with a high rate of hospitalisations that are related to increased mortality (5–7). To cope with the burden of clinical events, definite and timely diagnosis of HF is the key, but several studies have shown that HF is undiagnosed in up to 90% or misdiagnosed in up to 76% of nursing home residents (8, 9). The 2016 European Cardiology Society guidelines provide universal recommendations for the diagnosis and treatment of HF for all age groups (10). However, owing to the limited accessibility of diagnostic and therapeutic procedures, the needs of the nursing home population for secondary healthcare procedures often remain unmet (11, 12). The guidelines for both HF diagnosis and management are frequently not followed in the nursing home population, leading to sub-optimal or even inappropriate HF treatment, frequent instances of deterioration and poor quality of life (13). Both the diagnostics and management of heart failure in the nursing home population therefore remain important challenges for primary care physicians. Over the last decade, point-of-care ultrasonography (POCUS) has developed into an indispensable tool for bedside patient management, enabling the physician to acquire visual information easily, safely and quickly (14). In the HF management guidelines, POCUS is recommended to assess volume overload, i.e. assessing lung congestion, pleural effusion and inferior vena cava diameter (10, 15). To date, POCUS has been mostly studied for dichotomous decision-making in acute HF (16, 17), while the usefulness of POCUS in chronic HF management has not been widely investigated (18). Recent studies show that an estimate of sub-clinical lung congestion using POCUS is an important predictive factor for HF outcome in ambulatory patients (19). This enables the primary care physician to promptly adjust diuretic therapy in order to prevent a HF deterioration. This trial was conceived to test whether point-of-care ultrasonography-guided management improved HF outcomes among nursing home residents. The following issues were specifically addressed: 1. What is the prevalence of HF in nursing homes? 2. Does POCUS-guided HF management reduce the number of HF deteriorations in the nursing home population? 3. Should POCUS be integrated into the algorithm of HF management for the nursing home population? 2 METHODS 2.1 Study Design A multi-centre, prospective, randomised controlled trial will be conducted. 2.2 Setting Selected nursing home facilities provide long-term care for over 1,000 residents in several locations. Nursing home care is provided by a multidisciplinary team. Nursing home physicians are family medicine specialists who are responsible for all medical care, including the initiation of different diagnostic and therapeutic interventions, and palliative care. 2.3 Study Population The population will consist of nursing home residents. The demographic characteristics of this population are expected to reflect the general population in this age group with an average age of over 80 years and predominantly female. 2.4 Inclusion and Exclusion Criteria Inclusion criteria will be: a) nursing home residents and b) consent to participate in the study by the participant or by their legal representative. Exclusion criteria will be a) life expectancy of fewer than six months for a reason other than heart failure, b) residents on short-term or day care and c) residents unable to complete HF diagnostics for any reason. This population will be screened for HF using 2016 ESC guidelines for HF diagnosis, regardless of any pre-existing HF diagnosis (10). All nursing home residents with heart failure will be included in the intervention part of the study. 2.5 Selection of Participants The residents or their legal representatives will receive a letter describing the purpose and content of the study, an informed consent form, and a data administration consent form consistent with the EU General Data Protection Regulation (2016/679). If needed, residents will be able to obtain a further explanation of the study from the research coordinator at the nursing home. 2.6 Training of Nursing Home Physicians Nursing home physicians are presumed to be skilled in the management of heart failure. However, they will be encouraged to review the recent European guidelines on heart failure management (10) and will be able to consult a cardiologist at any time. Family medicine specialists are presumed to have no prior knowledge of bedside ultrasonography. They will undergo a four-hour supervised training session on the handling of the POCUS device and on the use of POCUS for volume assessment. The physicians will be trained in the assessment of B-lines in eight standard positions in a supine patient (Figure 2) and in the visualisation of the inferior vena cava, assessing its size and collapsibility (Table 2). During training, they will perform at least five supervised POCUS volume assessments. Later on, they will independently perform ten POCUS volume assessments, with the images being recorded. The recorded images will be evaluated and skill will be further developed under supervision if needed. An experienced POCUS provider will confirm the skill level achieved three weeks after the initial training. 2.7 Study Protocol The study protocol will consist of screening and intervention parts. It will follow the scheme presented in Figure 1. Figure 1. Study protocol scheme. 2.7.1 Screening of HF Screening for HF will follow the 2016 European Cardiology Society diagnostic algorithm for the diagnosis of HF of non-acute onset (10). All screening stages will take place in nursing home facilities. The diagnostic procedure to determine HF will include: 1) the assessment of HF probability by assessing clinical history, clinical signs and ECG, 2) the NT-proBNP measurement and 3) the echocardiography with clinical judgement. 2.7.2 Assessment of HF With the help of two junior researchers, the nursing home physicians will review residents’ history and perform a clinical examination to identify clinical signs of heart failure. They will have full access to residents’ medical records and will be able to assess multimorbidity. Trained nursing home staff will record ECG and collect blood samples for measurement of the NT-proBNP marker. NT-proBNP will be measured using a Roche Cobas h 232 point-of-care system on site. The ECG will be interpreted by a nursing home physician. A qualified cardiologist will perform the echocardiography exam using a GE Vivid 7 ultrasound system. While performing echocardiography, the cardiologist will be blinded for NT-proBNP value and will perform echocardiography on an additional 10% of NT-proBNP negative patients as a control measure. A pre­ defined ultrasonography protocol will be followed and images and clips recorded. 2.7.3 Diagnosis and Initial Treatment of Heart Failure After performing echocardiography, the cardiologist will have access to all patient data to diagnose or exclude HF. The current classification of HF will be used: heart failure with preserved (HFpEF), mid-range (HFmrEF) and reduced ejection fraction (HFrEF). For the diagnosis of HFmrEF and HFpEF, the following requirements will have to be met: presence of symptoms and/or signs of heart failure, left ventricular ejection fraction (LVEF) of =50% or 40–49%, NTproBNP =125 pg/mL, and objective evidence of other cardiac functional and structural alterations underlying heart failure. At the inclusion point, the cardiologist performing echocardiography will recommend a therapeutic management plan for HF patients. The cardiologist and the nursing home physicians will jointly optimise medication therapy, with due consideration given to current medication guidelines and the individual patient’s characteristics. From this point on, the patient will be managed by the nursing home physician. 2.7.4 Randomisation Patients diagnosed with HF will be randomised using block randomisation (block n=10) into intervention and control groups. The randomisation list will be performed by an independent statistics adviser. For the randomisation process, patients’ identification numbers will be used in place of a name. This is to avoid randomisation bias. The research coordinator will perform randomisation by applying the sealed envelope technique (20). 10.2478/sjph-2020-0017 2.7.5 Intervention Nursing home physicians will manage HF patients for six months by assessing volume status and aiming to prevent any significant HF deterioration. The volume assessment will be performed using POCUS and clinical signs in the intervention group, and only clinically in the control group. Patients in the control group will receive standard care in line with current HF guidelines and good clinical practice by the nursing home physician. The intervention group will receive the same clinical standards plus POCUS for volume evaluation. The follow-up of both the test and control groups will last for six months. The patients will be evaluated at regular time intervals, as presented in Table 1. Unplanned evaluations will be performed whenever HF deterioration is suspected and one week after diuretic therapy change. In the intervention group, nursing home physicians will use Samsung SonoAce R3 point-of-care devices. POCUS volume assessment will consist of the visualisation of B-lines on eight standard positions: the mid-clavicular line in the second and fourth intercostal spaces bilaterally, and the mid-axillary line in the second and fourth intercostal spaces bilaterally (Figure 2) (21). Inferior vena cava diameter and collapsibility will also be evaluated, as presented in Table 2. Table 1. Follow-up plan. Zdr Varst. 2020;59(3):128-136 Figure 2. Eight standard positions for visualisation of B-lines in lung POCUS. The inferior vena cava diameter and collapsibility will be assessed 2 cm below the junction with the right atrium (22, 23). It will be categorised as small, medium or large. The inferior vena cava will be considered collapsible if the inspiratory collapse is more than 50% of its diameter. Test-retest reliability At inclusion At inclusion At inclusion At inclusion At inclusion Intervention group Physical examination POCUS Evaluation of HF deteriorations + + + + + + + + + + + + --+ Control group Physical examination POCUS Evaluation of HF deteriorations + + + + -+ + -+ + -+ --+ Table 2. Inferior vena cava diameter and collapsibility evaluation (adapted and modified from Kircher, et al. (22) and Papadimos, et al. (23)). Category Estimated inferior vena Collapsibility Estimated central venous pressure cava diameter Small <1.5 cm >50% 0–5 mm Hg Medium 1.5–2.5 cm >50% 6–10 mm Hg <50% 11–15 mm Hg Large >2.5 cm <50% >16 mm Hg 2.7.6 Diuretic Modifications Nursing home physicians will monitor patients with HF for signs of volume overload. Volume overload will be assumed if any new HF-related symptoms appear (breathlessness, orthopnoea, paroxysmal nocturnal dyspnoea, reduced exercise tolerance, fatigue, tiredness, increased time to recover after exercise) that are consistent with any clinical signs of HF (pulmonary crepitation, ankle swelling, elevated jugular venous pressure, hepatojugular reflux, gallop rhythm, laterally displaced apex, weight change >2 kg/week). Additionally in the POCUS group, volume overload will be assumed if at least three B-lines are present in at least five out of eight regions of the thorax or if the inferior vena cava is found to be large (>2.5 cm) or medium-sized, but non-collapsible. Volume depletion will be assumed if B-lines are absent and the inferior vena cava is small and not collapsible, together with clinical signs of volume depletion. If the nursing home physicians assess volume overload, they will double the daily dose of diuretic and re-evaluate the patient in one week. If they find the patient volume depleted one week after the increase of the dose of diuretic, they will halve the daily dose of diuretic back to the initial dose. 2.7.7 Workload Evaluation The use of POCUS will also be assessed from the perspective of potential additional workload for nursing home physicians. The workload will be monitored with regard to the number of non-administrative contacts, therapy modifications and referrals. Furthermore, technical and other requirements for POCUS in NH will be documented. 2.8 Endpoints 2.8.1 Primary Endpoint The primary endpoint will be HF deterioration, defined as a composite of any of the following four events: the need for an intravenous diuretic application, the need for an emergency service intervention, the need for unplanned hospitalisation for non-injury causes, or death from whatever cause. 2.8.2 Secondary Endpoints Secondary endpoints will be: 1. A change in quality of life (self-evaluated) 2. A change in functional state caused by HF using the New York Heart Association (NYHA) score 3. The need for an intravenous diuretic application 4. The need for an emergency service intervention 5. The need for unplanned hospitalisation for non-injury causes 6. The number of days in hospital related to HF deterioration 7. The number of days alive and out of hospital 8. Death from whatever cause. 2.8.3 Other Outcomes The workload of nursing home physicians will be measured by counting the number of all and HF-related a) non- administrative contacts, b) therapy modifications and c) unplanned non-injury referrals. 2.9 Statistical Analysis 2.9.1 Sample Size Calculation The calculation of sample size was based on an estimated prevalence of HF in nursing home residents of p=0.25 and on an estimated incidence of heart failure composite events in six months of 50% (6, 17). In the intervention part of the research, we aim to decrease the number of patients with HF deterioration from 50% to 20% in six months. With a study power of 80% and an estimated statistical error of 5%, at least 90 residents with heart failure need to be included in the randomised controlled trial. With an expected prevalence of heart failure of p=0.25, at least 360 residents should be recruited for HF screening. The rate of response/participation in clinical studies in this population is expected to be about 30% (25). It will therefore probably be necessary to approach approx. 1,000 nursing home residents in order to yield 360 residents for HF screening. 2.9.2 Data Analysis The data will be analysed using the SPSS statistical software package. We will show frequencies, averages and the standard deviation of variables, or value ranges and median where applicable. Differences between groups will be tested using appropriate statistical methods, such as the T-test or analysis of variance (ANOVA) for continuous variables, and the Chi-square test and multivariable logistic regression analyses for discrete variables. As statistical significance, a p value of <0.05 will be used. 3 MEASUREMENTS The data required to answer the research questions is presented in Table 3. Table 3. Study data collection list (HF – heart failure; NYHA – New York Heart Association classification; HFrEF – heart failure with reduced ejection fraction; HFmrEF – heart failure with mid-range ejection fraction; HFpEF – heart failure with preserved ejection fraction). Category Data variable Measurement description Data source Demographic data Age In full years Medical record Gender Male or female Medical record Baseline clinical Multimorbidity Yes if more than 2 chronic diseases Medical record characteristics Charlson Comorbidity Index Using MDCalc software Medical record Previously diagnosed heart failure Yes if any evidence Medical record Current therapy Number of all prescribed medicines Medical record Start-point health barometer Self-evaluated Interview Start-point NYHA On scale I-IV Interview and clinical examination History of coronary artery disease Yes if any evidence Medical record Clinical history History of arterial hypertension Yes if any evidence Medical record Exposition to cardiotoxic Yes if any evidence Medical record drugs/radiation Use of diuretics Yes if any evidence Medical record Orthopnoea / paroxysmal Yes if declared or any evidence Interview or medical record nocturnal dyspnoea Signs of heart failure Rales Yes if bilateral Clinical examination Bilateral ankle oedema Yes if bilateral Clinical examination Heart murmur Yes if heard Clinical examination Jugular venous dilatation Yes if observed in sitting position Clinical examination Laterally displaced / Yes if felt Clinical examination broadened apical beat Diagnostics of heart failure Outcomes ECG NT-proBNP Echocardiography Events related to HF deterioration Days to deterioration of heart failure Change in health barometer Change in NYHA class Days in hospital due to heart failure Days alive and out of hospital Any abnormality Positive if =125 pg/mL Categorisation in HFrEF, HFmrEF, HFpEF The need for the iv diuretic, the emergency service intervention, hospitalisations for non-injury cause or death For any event related to HF deterioration Self-evaluated On scale I-IV For HF deterioration only Excluding hospital days for whatever cause Study Study Study Study Study Study Study Study Study Workload Days alive Non-administrative contacts Therapy modifications Unplanned referrals Time to death for whatever cause All and HF related All and HF related All and HF related Study Study Study Study 3.1 Demographic Data and Baseline Clinical Characteristics Demographic data (age and gender) and baseline clinical characteristics (list of therapy, list of previous medical conditions) will be gathered for all participants by nursing home physicians and researchers. This data will be used to assess multimorbidity, applying the Charlson Comorbidity Index (26) and using free online MDCalc software. Self-evaluation of health using a numerical and visual analogue scale from 0 to 100 will be performed for patients diagnosed with HF, functional state under the New York Heart Association classification (27). 3.2 HF Screening and Diagnostics Symptoms and signs of HF will be obtained for all participants. ECG and NT-proBNP measurement will be recorded. Echocardiography will be performed on all patients with NT-proBNP =125 ng/ml. HF will be classified according to left ventricle ejection fraction (LVEF). 3.3 Intervention Outcomes Events related to HF deterioration will be monitored as a composite event and separately: the need for an IV diuretic, emergency service intervention, hospitalisation for non-injury cause, or death. Days in hospital for HF and days alive and out of hospital will be recorded. The change in the functional state of residents will be determined by the change in the NYHA score and the self-evaluation of health score at the end of the study. Measures related to the workload of nursing home physicians will be monitored: the frequency of non-administrative contacts, therapy modifications and unplanned non-injury referrals. 4 DISCUSSION This study will provide an insight into the use of POCUS for HF management in nursing homes. This is the first study to investigate the use of the point-of-care approach in a nursing home setting and for non-acute disease management. Nursing home patients with HF must have their need for diuretics continuously evaluated. They are unpredictable in their hydration habits (28) as they often do not drink enough while still ingesting diuretics. It is just as likely that they do not follow individual daily fluid restrictions. They are susceptible to a deterioration in renal function due to diuretic overuse, which can lead to an electrolyte imbalance and acute renal failure. On the other hand, they are sensitive to fluid overload, which can rapidly cause pulmonary congestion and symptomatic HF deterioration. The use of diuretics should therefore be reassessed frequently and monitored closely. Clinical examination alone is often not sensitive enough to detect subtle changes in the volume status of HF patients. In tandem with a clinical examination, POCUS is a useful and reliable tool for volume status evaluation. It is non-invasive, and is also applicable to patients with limited access to other diagnostic options. The technique of volume assessment using POCUS can be reliably mastered in a short time by different profiles of health workers (18). Using POCUS, volume status is evaluated by assessing inferior vena cava size and by performing lung ultrasonography. The inferior vena cava size reflects fluid intake, and the lung ultrasonography findings change rapidly to diuretic therapy (17, 19). This information enables the prompt dose adjustment of diuretics in response to volume status (18). This study will be based on actual prevalence of HF. Several studies of HF prevalence in the nursing home population have shown that prevalence is higher than expected in the comparable age group and that HF is often undiagnosed or misdiagnosed (8, 25, 29). There are several factors that make this more likely, but the accessibility and feasibility of diagnostic procedure of HF are the most common (13). To overcome this, and to ensure equity for all participants, the whole diagnostic procedure of HF in this study will be performed on-site in nursing homes. The follow-up of HF patients enrolled in the study will continue for six months. Based on studies investigating hospital readmissions of HF patients due to deterioration, there is an approximately 50% chance of HF deterioration in this time period and for this age group (6, 17). However, due to the lack of data for the nursing home population, this assumption is based on patients hospitalised for HF. If the incidence of events related to deterioration is lower than assumed, the observed period could be too short or the sample too small. This could be a limitation of the study. Another limitation could be insufficiencies in the POCUS teaching module, as the investigators’ POCUS skills will allow them to perform only volume evaluation based on B-lines and VCI size and collapsibility. They will not be able to evaluate any other aspect of HF deterioration or identify any other conditions with similar clinical presentation. In the case of clinically significant deteriorations, nursing home physicians will need to follow standard protocols of care. Other limitations of the study could be a delay in the screening phase of the study, poor performance of POCUS due to increased physician workload, and variability in the diuretic modification in response to volume change. The originality of this study is in its assessment of the applicability of POCUS for chronic disease follow-up in primary care. The findings might justify a novel approach to HF management in the nursing home population. 10.2478/sjph-2020-0017 5 CONCLUSION The HARMONIOUS trial is designed to test the importance of POCUS performed by nursing home physicians in HF management. The timely and exact assessment of volume status using POCUS might enable optimal diuretic therapy adjustment, resulting in fewer HF-related events. If so, POCUS could be integrated into the algorithm for HF management in the nursing home population. CONFLICTS OF INTEREST The authors declare that no conflicts of interest exist. FUNDING The study will be financed by Department of Family Medicine, Faculty of Medicine, University of Ljubljana, Slovenia, and by the Institute for the Development of Family Medicine, Ljubljana, Slovenia. ETHICAL APPROVAL AND REGISTRATION The authors of this paper hereby declare that the study complies with the Declaration of Helsinki and that it has been approved by the Slovenian National Medical Ethics Committee (KME 41/06/17). The study is registered in the German clinical trial registry (DRKS00012911). REFERENCES 1. Mosterd A, Hoes AW. Clinical epidemiology of heart failure. Heart. 2007;93(9):1137-46. doi: 10.1136/hrt.2003.025270. 2. Bleumink GS, Knetsch AM, Sturkenboom MC, Straus SM, Hofman A, Deckers JW, et al. Quantifying the heart failure epidemic: prevalence, incidence rate, lifetime risk and prognosis of heart failure: the Rotterdam study. Eur Heart J. 2004;25(18):1614-9. doi: 10.1016/j. ehj.2004.06.038. 3. Redfield MM, Jacobsen SJ, Burnett JC, Mahoney DW, Bailey KR, Rodeheffer RJ. Burden of systolic and diastolic ventricular dysfunction in the community: appreciating the scope of the heart failure epidemic. JAMA. 2003;289(2):194-202. doi: 10.1001/jama.289.2.194. 4. Ceia F, Fonseca C, Mota T, Morais H, Matias F, Sousa A de, et al. Prevalence of chronic heart failure in Southwestern Europe: the EPICA study. Eur J Heart Fail. 2002;4(4):531-9. doi: 10.1016/s1388­9842(02)00034-x. 5. Daamen MAMJ, Schols JMGA, Jaarsma T, Hamers JPH. Prevalence of heart failure in nursing homes: a systematic literature review. Scand J Caring Sci. 2010;24(1):202-8. doi: 10.1111/j.1471-6712.2009.00708.x. 6. Omersa D, Farkas J, Erzen I, Lainscak M. National trends in heart failure hospitalization rates in Slovenia 2004–2012. Eur J Heart Fail. 2016;18(11):1321-8. doi: 10.1002/ejhf.617. 7. Christ M, Störk S, Dörr M, Heppner HJ, Müller C, Wachter R, et al. Heart failure epidemiology 2000–2013: insights from the German Federal Health Monitoring System. Eur J Heart Fail. 2016;18(8):1009­ 18. doi: 10.1002/ejhf.567. Zdr Varst. 2020;59(3):128-136 8. Barents M, van der Horst ICC, Voors AA, Hillege JL, Muskiet FAJ, De Jongste MJL. Prevalence and misdiagnosis of chronic heart failure in nursing home residents: the role of B-type natriuretic peptides. Neth Heart J. 2008;16(4):123-8. doi: 10.1007/BF03086130. 9. Hancock HC, Close H, Mason JM, Murphy JJ, Fuat A, Singh R, et al. High prevalence of undetected heart failure in long-term care residents: findings from the Heart Failure in Care Homes (HFinCH) study. Eur J Heart Fail. 2013;15(2):158-65. doi: 10.1093/eurjhf/hfs165. 10. Ponikowski P, Voors AA, Anker SD, Bueno H, Cleland JGF, Coats AJS, et al. 2016 ESC Guidelines for the diagnosis and treatment of acute and chronic heart failure: The Task Force for the diagnosis and treatment of acute and chronic heart failure of the European Society of Cardiology (ESC). Developed with the special contribution of the Heart Failure Association (HFA) of the ESC. Eur J Heart Fail. 2016;18(8):891-975. doi: 10.1002/ejhf.592. 11. Hlebec V, Srakar A, Majcen B. Determinants of unmet needs among Slovenian old population. Zdr Varst. 2016;55(1):78–85. doi: 10.1515/ sjph-2016-0011. 12. Hlebec V. Evaluation of access to long-term care services for old people ageing in place in Slovenia. Zdr Varst. 2018;57(3):116-23. doi: 10.2478/sjph-2018-0015. 13. Heckman GA, Shamji AK, Ladha R, Stapleton J, Boscart V, Boxer RS, et al. Heart failure management in nursing homes: a scoping literature review. Can J Cardiol. 2018;34(7):871-80. doi: 10.1016/j. cjca.2018.04.006. 14. Moore CL. Point-of-Care Ultrasonography. N Engl J Med. 2011;364(8):749-57. doi: 10.1056/NEJMra0909487. 15. International Liaison Committee on Lung Ultrasound (ILC-LUS) for the International Consensus Conference on Lung Ultrasound (ICC-LUS), Volpicelli G, Elbarbary M, Blaivas M, Lichtenstein DA, Mathis G, et al. International evidence-based recommendations for point-of-care lung ultrasound. Intensive Care Med. 2012;38(4):577-91. doi: 10.1007/ s00134-012-2513-4. 16. Prosen G, Klemen P, Strnad M, Grmec Š. Combination of lung ultrasound (a comet-tail sign) and N-terminal pro-brain natriuretic peptide in differentiating acute heart failure from chronic obstructive pulmonary disease and asthma as cause of acute dyspnea in prehospital emergency setting. Crit Care. 2011;15(2):R114. doi: 10.1186/cc10140. 17. Platz E, Lewis EF, Uno H, Peck J, Pivetta E, Merz AA, et al. Detection and prognostic value of pulmonary congestion by lung ultrasound in ambulatory heart failure patients. Eur Heart J. 2016;37(15):1244-51. doi: 10.1093/eurheartj/ehv745. 18. Gundersen GH, Norekval TM, Haug HH, Skjetne K, Kleinau JO, Graven T, et al. Adding point of care ultrasound to assess volume status in heart failure patients in a nurse-led outpatient clinic. A randomised study. Heart. 2016;102(1):29-34. doi: 10.1136/heartjnl-2015-307798. 19. Platz E, Merz AA, Jhund PS, Vazir A, Campbell R, McMurray JJ. Dynamic changes and prognostic value of pulmonary congestion by lung ultrasound in acute and chronic heart failure: a systematic review. Eur J Heart Fail. 2017;19(9):1154-63. doi: 10.1002/ejhf.839. 20. Torgerson DJ, Roberts C. Randomisation methods: concealment. BMJ. 1999;319(7206):375-6. doi: 10.1136/bmj.319.7206.375. 21. Gargani L, Volpicelli G. How I do it: lung ultrasound. Cardiovasc Ultrasound. 2014;12:25. doi: 10.1186/1476-7120-12-25. 22. Kircher BJ, Himelman RB, Schiller NB. Noninvasive estimation of right atrial pressure from the inspiratory collapse of the inferior vena cava. Am J Cardiol. 1990;66(4):493-6. doi: 10.1016/0002-9149(90)90711-9. 23. Kelly N, Esteve R, Papadimos T, Sharpe R, Keeney S, deQuevedo II R, et al. Clinician-performed ultrasound in hemodynamic and cardiac assessment: a synopsis of current indications and limitations. Eur J Trauma Emerg Surg. 2015;41(5):469-80. doi: 10.1007/s00068-014-0492­ 6. 24. Omersa D, Lainscak M, Eržen I, Farkas J. Mortality and readmissions in heart failure: an analysis of 36,824 elderly patients from the Slovenian national hospitalization database. Wien Klin Wochenschr. 2016;128(Suppl 7):512-8. doi: 10.1007/s00508-016-1098-2. 25. Daamen MAMJ, Hamers JPH, Gorgels APM, Brunner-La Rocca H-P, Tan FES, van Dieijen-Visser MP, et al. Heart failure in nursing home residents; a cross-sectional study to determine the prevalence and clinical characteristics. BMC Geriatr. 2015;15:167. doi: 10.1186/s12877­015-0166-1. 26. Charlson ME, Pompei P, Ales KL, MacKenzie CR. A new method of classifying prognostic comorbidity in longitudinal studies: development and validation. J Chronic Dis. 1987;40(5):373-83. doi: 10.1016/0021-9681(87)90171-8. 27. Dolgin M, editor. Committee NYHAC. Nomenclature and criteria for diagnosis of diseases of the heart and great vessels. 9th ed. Boston : Little, Brown, 1994. Available Aug 13 2019 at: https://trove.nla.gov. au/version/13288061. 28. Cook G, Hodgson P, Hope C, Thompson J, Shaw L. Hydration practices in residential and nursing care homes for older people. J Clin Nurs. 2019;28(7-8):1205-15. doi: 10.1111/jocn.14727. 29. Bolmsjö BB, Mölstad S, Östgren CJ, Midlöv P. Prevalence and treatment of heart failure in Swedish nursing homes. BMC Geriatr. 2013;13:118. doi: 10.1186/1471-2318-13-118. QUALITY OF LIFE ASSESSMENT IN PATIENTS WITH MALOCCLUSION UNDERGOING ORTHODONTIC AND ORTHOGNATHIC TREATMENT OCENA KAKOVOSTI ŽIVLJENJA PRI PACIENTIH Z MALOKLUZIJO, PRI KATERIH SE IZVAJA ORTODONTSKO IN ORTOGNATSKO ZDRAVLJENJE Ljiljana VUCIC1, Branislav GLIŠIC1, Uroš VUCIC1, Jelena DRULOVIC2, Tatjana PEKMEZOVIC3* Received: Jul 5, 2019 Accepted: May 5, 2020 ABSTRACT Keywords: malocclusions, quality of life, orthodontic therapy, orthognathic therapy IZVLECEK Kljucne besede: malokluzije, kakovost življenja, ortodontsko zdravljenje, ortognatsko zdravljenje 1University of Belgrade, School of Dental Medicine, Department of Orthodontics, Dr Subotica 8, 11000 Belgrade, Serbia 2Clinic of Neurology, Clinical Center of Serbia, Faculty of Medicine, University of Belgrade, Dr Subotica 6, 11000 Belgrade, Serbia 3University of Belgrade, Faculty of Medicine, Institute of Epidemiology, Visegradska 26A, 11000 Belgrade, Serbia Original scientific article Introduction: The objective of this study was to assess pre-treatment quality of life and the relevant clinical variables in adult patients with malocclusion in order to improve orthodontic treatment strategies. Methods: The study was conducted in 240 consecutive adult patients with malocclusions divided into two groups: patients for whom an orthodontic treatment plan was considered, and patients for whom an orthognathic treatment plan was selected. Patients were examined between December 2015 and February 2017, at the School of Dental Medicine, University of Belgrade. Malocclusion severity was recorded using the Peer Assessment Rating index pre­treatment score. Skeletal malocclusion parameters were measured using lateral cephalometric radiographs. Quality of life was assessed by means of a generic questionnaire (Medical Outcomes Study Short Form-36 (SF-36)), and the disease-specific Orthognathic Quality of Life Questionnaire (OQLQ). Results: There were significant differences in the mean values of the OQLQ domain scores between orthodontic and orthognathic patients. Patients for whom orthodontic treatment was planned had statistically significantly lower scores in comparison to those for whom orthognathic treatment was planned. This was the case in all OQLQ domains except for “Awareness of facial deformity”. Statistically significant correlations (p<0.05) were presented between OQLQ scores and following demographic and clinical variables: gender, age, malocclusion severity, maxillary and mandibular sagittal, maxillary vertical, and lower incisor positions, intermaxillary angle, and the Beck Depression Inventory and Beck Anxiety Inventory levels. The independent predictors for the planning of orthodontic and orthognathic treatment in patients with malocclusion were two OQLQ domains, “Facial aesthetics” and “Awareness of facial deformity”, as well as total OQLQ score, after adjustment for demographic characteristics, skeletal parameters, anxiety and depression. Conclusions: Our findings suggest that patients for whom orthodontic treatment was planned demonstrated better quality of life according to the OQLQ scores in comparison to those for whom orthognathic therapy was planned. Uvod: Cilj te študije je bil oceniti kakovost življenja pred zdravljenjem in zadevne klinicne spremenljivke pri odraslih pacientih z malokluzijo, da bi lahko izboljšali strategije zdravljenja. Metode: V študijo smo vkljucili 240 zaporednih odraslih pacientov z malokluzijo, ki smo jih razdelili na dve skupini: v prvi so bili pacienti, pri katerih je bil predviden nacrt ortodontskega zdravljenja, pri drugi pa je bil izbran nacrt ortognatskega zdravljenja. Bolnike smo pregledovali med decembrom 2015 in februarjem 2017 na Stomatološki fakulteti Univerze v Beogradu. Resnost malokluzije smo evidentirali z rezultatom pred zdravljenjem po indeksu PAR (Peer Assessment Rating). Parametre skeletne malokluzije smo izmerili na lateralnih cefalometricnih radiogramih. Kakovost življenja smo ocenili s splošnim vprašalnikom v kratki obliki s 36 izjavami glede medicinskih izidov (SF-36), in za bolezen specificnim vprašalnikom o ortognatski kakovosti življenja (OQLQ). Rezultati: Pri povprecnih vrednostih rezultatov vprašalnika OQLQ je med ortodontskimi in ortognatskimi pacienti prišlo do pomembnih razlik. Pacienti, predvideni za ortodonsko zdravljenje, so imeli v primerjavi s pacienti, predvidenimi za ortognatsko zdravljenje, statisticno pomembno nižje rezultate pri vseh elementih vprašalnika OQLQ, razen pri zavedanju obrazne deformacije. Pokazale so se statisticno pomembne korelacije (p < 0,05) med rezultati OQLQ ter naslednjimi demografskimi in klinicnimi spremenljivkami: spol, starost, resnost malokluzije, sagitalni položaj maksile in mandibule, vertikalni položaj maksile, položaj spodnjih sekalcev, intermaksilarni kot, rezultati po Beckovi lestvici depresivnosti in Beckovi lestvici tesnobe. Neodvisni prediktorji za nacrtovanje ortodontskega in ortognatskega zdravljenja pri pacientih z malokluzijo so bili dva elementa vprašalnika OQLQ – obrazna estetika in zavedanje obrazne deformacije, ter skupni rezultat OQLQ, in sicer po prilagoditvi glede na demografske znacilnosti, skeletne parametre, tesnobo in depresijo. Sklep: Naše ugotovitve kažejo, da je bila kakovost življenja pri pacientih, predvidenih za ortodontsko zdravljenje, glede na rezultate OQLQ boljša kot pri pacientih, predvidenih za ortognatsko zdravljenje. *Corresponding author: Tel. + 381 11 360 70 62; E-mail: pekmezovic@sezampro.rs © National Institute of Public Health, Slovenia. 1 INTRODUCTION Malocclusion is a multifactorial dentofacial disorder which occurs in the majority of persons in population (1). Although it is not considered a disease, malocclusion can significantly affect orofacial aesthetics, oral functions and oral health (2). Disturbed aesthetics and function in this region can lead to psychological and social problems and, particularly in the domain of psychosocial adaptation, may potentially have an adverse effect on quality of life (3). Despite Angle’s widely accepted qualitative classification of malocclusion (4), quantitative occlusal indices such as the Index of Orthodontic Treatment Need (IOTN) (5) and the Peer Assessment Rating Index (PAR index) (6) were created in order to provide easy, uniform and reproducible malocclusion recordings. Those qualitative and quantitative objective measures are important for malocclusion diagnostic procedures, therapeutic decisions and malocclusion epidemiology. However, when considering the necessity of orthodontic treatment and patient treatment outcome satisfaction, Patient-Centred Measures (PCM) are also recommended (7). Additionally, Health-Related Quality of Life (HRQoL) and Oral Health-Related Quality of Life (OHRQoL) measures can give great insight into the impact of health, disease, care and treatment (8). Specific instruments sensitive enough to detect changes in the quality of life in persons with malocclusion have therefore been created; these include the Orthognathic Quality of Life Questionnaire (OQLQ) (9, 10) and the Malocclusion Impact Questionnaire (MIQ) (11-13). Studies related to malocclusion and quality of life have played a significant role in scientific literature in recent years (14-17). It has been consistently demonstrated that malocclusions have harmful effects on OHRQOL, predominantly in the domains of emotional and social well-being. Additionally, the routine clinical application of quality of life measures in orthodontics is still limited. However, findings from studies on quality of life may have a potentially significant role in improving the quality of orthodontic care (3, 18). Since the quality of life concept is multidimensional and dynamic, many factors influence malocclusion-related quality of life, such as: the demographic, cultural and social characteristics of the observed population, the timing and frequency of measurement, and the appropriate choice of measuring instruments (19). Finally, additional factors that also influence malocclusion-related quality of life are anxiety, depression and self-esteem (20-22). The objective of this study was to assess pre-treatment quality of life and the relevant clinical variables in adult patients with malocclusion in order to potentially improve orthodontic treatment strategies. 2 METHODS 2.1 Study Design This is a cross-sectional study comprising all consecutive patients from the Department of Orthodontics, School of Dental Medicine, University of Belgrade, from December 2015 to February 2017. 2.2. Observed Population In this study, the group consisted of 240 participants, all young adults who presented consecutively at the Department of Orthodontics, School of Dental Medicine, University of Belgrade and expressed a personal desire to have their malocclusion corrected. The inclusion criteria were the presence of malocclusion, a personal desire for orthodontic treatment, age 17+ years and signed informed consent form. Patients who had already had orthodontic treatment, and patients with craniofacial deformities (e.g. cleft lip, cleft palate and syndromes) were excluded. Before enrolment, all the subjects provided signed informed consent. The study was approved by the Ethics Committee of the School of Dental Medicine, University of Belgrade (No 1/2016). Standard orthodontic diagnostic procedures were performed and diagnosis established for all participants. The diagnostic procedure included: interview, medical and dental history, clinical evaluations of oral health, jaw and occlusal function, facial and dental appearance, and an analysis of diagnostic records. 2.3. Study Instrument Malocclusion severity was measured using the pre­treatment Peer Assessment Rating index (PAR index). This index was created for assessing the outcome of orthodontic treatment, and has also been used for assessing and recording malocclusion severity (6). More severe malocclusion was given a higher single PAR pre­treatment score. In this study, the PAR index was assessed by one senior dentist (specialist in orthodontics) trained in PAR index measurement. The components of PAR index have to be weighted. In this study, the British weighting values were used. Skeletal malocclusion components were assessed by tracing and measuring angular and linear skeletal relations using lateral cephalometric radiographs. The manual measuring method was performed by a senior dentist/ specialist in orthodontics. In order to analyse the jaw anteroposterior relationship, the jaw vertical relationship, the rotation of the jaw bases, incisor position, type of facial growth and the dimension of the jaw bases, angles and linear parameters (anterior face height N-Me, posterior face height S-Go, anterior cranial base length Se-N, upper and lower jaw base length, mandibular corpus length and mandibular ramus length) were measured and recorded. The cephalometric measurements were interpreted and the values of all skeletal measures defined in accordance with the average values of the corresponding parameters (23) (Table 1). Prior to discussing treatment options, participants completed five self-reporting Serbian versions of the following questionnaires: Medical Outcomes Study Short Form-36 (SF-36) (24), Orthognathic Quality Of Life (OQLQ) (9, 10, 25), Beck Depression Inventory (BDI) (26), Beck Anxiety Inventory (BAI) (27), and Rosenberg Self-Esteem Scale (RSES) (28). Demographic and clinical data was collected by the investigator. 2.4 Observed Outcome After diagnostic procedures and detailed discussion with patients had been performed, all participants were divided in two groups in accordance with the treatment options: patients for whom an orthodontic treatment plan was considered, and patients for whom an orthognathic treatment plan was selected. 2.5 Explanatory Factors The variables that were analysed as potential explanatory factors responsible for the variability of observed outcomes were the different domains of the OQLQ (“Social aspects of deformity”, “Facial aesthetics”, “Oral function”, “Awareness of facial deformity”) and the total OQLQ. Table 1. List of malocclusion skeletal parameters analysed in the study of quality of life assessment in patients with malocclusion undergoing orthodontic and orthognathic treatment in Serbia. Parameters* Author* < = Average value > ANB Stainer skeletal class III skeletal class I skeletal class II (2-4)° SNA Stainer maxillary retrognathism average sagittal position maxillary prognathism 82° SNB Stainer mandibular retrognathism average sagittal position mandibular prognathism 80° SN/SpP Stainer maxillary ante inclination maxillary normal inclination maxillary retro inclination 12° SN/MP Stainer mandibular forward rotation mandibular neutral rotation mandibular backward rotation 32° SpP/MP Schwarc skeletal deep bite normal bite skeletal open bite 20° Bjork Bjork horizontal face growth neutral face growth vertical face growth 396° Jarebach Jarebach vertical face growth neutral face growth horizontal face growth (62–65)% I/SpP Schwarz .incisors labial inclination .incisors normal inclination .incisors oral inclination (65–75)° i/MP Schwarc .incisors lab. inclination .incisors normal inclination .incisor oral inclination (87–93)° C max Schwarc short maxillary corpus average maxillary corpus long maxillary corpus (7/10 NSe ) C mand Schwarc short mandibular corpus average mandibular corpus long mandibular corpus (21/20 NSe ) C ram Schwarc short mandibular ramus average mandibular ramus long mandibular ramus (5/7 Cmnd) *Source: Ozerovic, 1985 (23); ANB – sagittal angle between upper and lower jaw; SNA – sagittal angle between base of skull and upper jaw; SNB – sagittal angle between base of skull and lower jaw; SN/SpP – vertical angle between base of skull and upper jaw; SN/MP – vertical angle between base of skull and lower jaw; SpP/MP – vertical angle between upper and lower jaw; Bjork – type of face growth according to skeletal angles; Jarebach – type of face growth according to vertical face proportions; I/SpP – sagittal inclination of upper incisors; i/MP – sagittal inclination of lower incisors; C max – length of maxillary base; C mand – length of mandibular base; C ram – length of mandibular ramus 2.6 Confounding Factors Confounding factors are variables that influence both the dependent variable and independent variable, causing a false association. In our investigation, demographic characteristics, skeletal parameters, anxiety and depression were considered as potential confounding factors. 2.7 Methods of Analysis For the comparison of categorical variables, the .2 test was used. An analysis of variance (ANOVA) was performed for continuous variables. Correlation analysis examined the relationship between two variables, and Pearson’s correlation test (for continuous variables) and Spearman’s test (for categorical variables) were used, depending on the data distribution. The predictive value of the baseline scores of the different domains of OQLQ (independent variables) for different treatment options (dependent variable: treatment – orthodontic or orthognathic), adjusted by demographic characteristics, skeletal parameters, anxiety and depression, were assessed by using logistic regression analyses. In order to assess the reliability of the generic (SF-36) and specific (OQLQ) questionnaires, we performed additional logistic regression analyses in the same manner. We used odds ratio (OR) with corresponding 95% confidence intervals (CI) as a measure of effect, and a p-value of 0.05 was considered as statistically significant. 3 RESULTS Out of 240 patients who met the inclusion criteria, 104 (43.3%) were male and 136 (56.7%) female, with an average age of 21 years (range 17–39). The mean pre-treatment PAR index, as a measure of malocclusion severity, was 32.2 ±11.68 (range 5–57). The majority of participants (132, 55%) had PAR index pre­treatment values of between 30 and 49. Table 2 shows the mean values of malocclusion severity measured using the PAR index in the groups with different treatment options. Table 2. Clinical variables in the study of quality of life assessment in patients with malocclusion undergoing orthodontic and orthognathic treatment in Serbia. Variables n Mean±SD / Median±SD Range Age 236 21.0±4.4 17–39 PAR index pre-treatment score All 240 32.2±11.7 5–57 Orthodontic treatment 82 22.3±9.1 5–50 Orthognathic treatment 92 39.4±9.3 12–57 Refused orthognathic treatment 66 34.5±8.7 17–55 Cephalometric parameters . ANB 230 1°±4.60 -11.0–13.0 . SpP/MP 230 25.52°±7.28 3.0–43.0 . SNA 230 80.45°±4.45 68.0–98.0 . SNB 230 79.61°±5.95 62.0–100.0 . SN/SpP 230 9.05°±3.40 0.0–20.0 . SN/MP 230 34.48°±7.67 11.5–56.0 . I/SpP 231 65.09°±8.53 39.0–90.0 . i/MP 231 95.6°±6.01 67.0–98.9 Bjork 229 394.0°±7.97 371.0–417.0 Jarebach 229 64.7%±6.08 45.0–85.0 Maxillary. Corpus Length. Discrepancy 230 0.0mm±3.52 -12.0–14.0 Mandibular Corpus. Length. Discrepancy 230 2.9mm±5.97 -35.0–18.6 Mandibular Ram. Length. Discrepancy. 230 5.8mm±5.75 -15.0–25.5 ANB – sagittal angle between upper and lower jaw; SNA – sagittal angle between base of skull and upper jaw; SNB – sagittal angle between base of skull and lower jaw; SN/SpP – vertical angle between base of skull and upper jaw; SN/MP – vertical angle between base of skull and lower jaw; SpP/MP – vertical angle between upper and lower jaw; Bjork – type of face growth according to skeletal angles; Jarebach – type of face growth according to vertical face proportions; I/SpP – sagittal inclination of upper incisors; i/MP – sagittal inclination of lower incisors; The mean values of all cephalometric variables are in total, orthodontic treatment was planned for 82 presented in Table 2 and the frequencies of various participants (34.2%) and orthognathic treatment for 158 malocclusion skeletal variables in Table 3. Of the group participants (65.8%). Table 3. Distribution of patients according to the pre-treatment values of various clinical and cephalometric parameters in the study of quality of life assessment in patients with malocclusion undergoing orthodontic and orthognathic treatment in Serbia. n % PAR (0–9) 7 2.9% n=240 (10–29) 90 37.5% (30–49) 132 55.0% (>50) 11 4.6% . ANB n=230 class III skeletal malocclusion class I skeletal malocclusion class II skeletal malocclusion 126 51 53 54.8% 22.2% 23.0% . pP/MP n=230 low intermaxillary angle average intermaxillary angle high intermaxillary angle 42 68 120 17.5% 29.6% 52.2% . SNA n=230 maxillary retrognathism maxillary orthognathism maxillary prognathism 124 23 83 53.9% 10.0% 36.1% . SNB n=230 mandibular retrognathism mandibular orthognathism mandibular prognathism 114 19 97 49.5% 8.3% 42.2% . SN/SpP n=230 maxillary anteinclination maxillary normal inclination maxillary retroinclination 176 26 28 76.5% 11.3% 12.2% . SN/MP n=230 mandibular forward rotation mandibular neutral rotation mandibular backward rotation 81 16 133 35.2% 7.0% 57.8% . I/SpP n=230 upper incisors labial inclination upper incisors normal inclination upper incisors oral inclination 129 77 25 55.8% 33.4% 10.8% . i/MP n=230 lower incisors labial inclination lower incisors normal inclination lower incisors oral inclination 89 34 108 38.5% 14.7% 46.8% Maxillary corpus length short normal long 87 78 64 37.9% 34.3% 27.8% Mandibular corpus length short normal long 47 40 142 20.5% 17.8% 61.7% Mandibular ramus length short normal long 26 20 184 11.3% 8.7% 80.0% Facial growth vertical facial growth neutral facial growth horizontal facial growth 88 39 102 38.5% 17.0% 44.5% PAR – Peer Assessment Rating Index; ANB – sagittal angle between upper and lower jaw; SNA – sagittal angle between base of skull and upper jaw; SNB – sagittal angle between base of skull and lower jaw; SN/SpP – vertical angle between base of skull and upper jaw; SN/ MP – vertical angle between base of skull and lower jaw; SpP/MP – vertical angle between upper and lower jaw; Bjork – type of face growth according to skeletal angles; Jarebach – type of face growth according to vertical face proportions; I/SpP – sagittal inclination of upper incisors; i/MP – sagittal inclination of lower incisors; An analysis of SF-36 scores showed that the Composite Score of Physical Functioning (85. 9±16.5) was higher than the Composite Score of Mental Functioning (75.7±21.8). The two composite scores, physical and mental functioning, are derived from a weighted combination of the scale scores. Physical Health Composite includes Physical Functioning, Role Physical, Bodily Pain and General Health scale scores. Mental Health Composite comprises Vitality, Social Functioning, Role Emotional, and Mental Health scale scores. The worst score was for the domain of Vitality (66.5±21.1), and the highest score and the best quality of life was noticed in the domain of Physical Functioning (94.8±15.5) (Figure 1). Quality of life was subsequently assessed using OQLQ, which showed the highest mean score in the domain of the “Social aspects of deformity”, and the lowest score in the domain of “Awareness of deformity” (Figure 2). Domain, composite and total scores of SF-36 questionnaire. Domain and total scores of OQLQ questionnaire. BDI scores showed that of the 240 participants, eight (3.3%) had moderate symptoms of depression and only two (0.8%) had severe depression. The mean BDI score in our group was 5.0±6.9 (range 0–63). The BAI scores showed that 75% participants did not have symptoms of anxiety. Moderate and severe anxiety was detected in the same proportion of patients (12.5%). The mean value of the BAI score in the cohort was 6.2±7.7 (range 0–41). The level of self-esteem as measured by the Rosenberg scale showed a mean value of 28.3±6.3 (range 0–39). Table 4 presents the results of the correlation analyses between the OQLQ domain score and the different demographic and clinical variables. Statistically significant positive correlations were demonstrated between all OQLQ domains scores and total score and gender and malocclusion severity. Additionally, a statistically significant positive correlation (p<0.01) was detected between all OQLQ domains and total scores and BDI and BAI, and OQLQ. Table 4. Correlation analyses between OQLQ scores and clinical variables in the study of quality of life assessment in patients with malocclusion undergoing orthodontic and orthognathic treatment in Serbia. OQLQ Gender Sagittal Sagittal Maxillary B angle Lower Thera- PAR Age BDI BAI domains maxillary mandibular rotation incisor peutic score score score position position inclination option Social aspects . 0.135 -0.142 -0.142 -0.144 -0.168 0.028 0.174 r 0.235 -0.083 0.401 0.305 of deformity p 0.037 0.105 0.032 0.029 0.011 0.668 0.007 p 0.001 0.204 0.001 0.001 Facial . 0.232 -0.14 -0.116 -0.069 -0.084 0.029 0.251 r 0.142 -0.026 0.371 0.288 aesthetics p 0.001 10.033 0.078 0.301 0.205 0.028 0.001 P 0.028 0.688 0.001 0.001 Oral . 0.189 -0.009 -0.080 -0.059 -0.039 0.138 0.218 r 0.142 0.158 0.238 0.207 function p 0.003 0.898 0.226 0.377 0.554 0.037 0.001 p 0.028 0.015 0.001 0.001 Awareness of . 0.236 -0.226 -0.083 -0.104 -0.127 -0.123 0.100 r -0.006 -0.063 0.376 0.391 facial deformity p 0.001 0.001 0.211 0.115 0.055 0.062 0.122 p 0.925 0.335 0.001 0.001 Total . 0.236 -0.146 -0.129 -0.124 -0.142 0.023 0.125 r 0.179 -0.22 0.434 0.363 p 0.001 0.027 0.050 0.061 0.031 0.723 0.001 P 0.005 0.739 0.001 0.001 According to the findings presented in Table 5, a statistically significant difference between the different treatment options was detected for the total OQLQ score and all its domains, except for the “Awareness of facial deformity” domain. Patients for whom orthodontic treatment was planned had statistically significantly lower scores in comparison to those for whom orthognathic treatment was planned. This was the case in all OQLQ domains except for “Awareness of facial deformity”. There was no statistically significant difference in mean OQLQ domains and total score between the orthognathic group and those who had been refused orthognathic treatment (data not shown). Table 5. OQLQ scores according to the various treatment options in the study of quality of life assessment in patients with malocclusion undergoing orthodontic and orthognathic treatment in Serbia. Social aspects 6.5±7.7 10.6±9.8 0.001 of deformity Facial 6.6±5.1 9.7±6.1 <0.001 aesthetics Oral function 4.7±4.7 6.2±4.9 0.003 Awareness of 6.1±4.8 6.7±4.8 0.360 facial deformity Total 23.9±18.0 33.9±21.3 <0.001 According to the results presented in Table 6, the independent predictors for the planning of orthodontic and orthognathic treatment in patients with malocclusion were two OQLQ domains, “Facial aesthetics” and “Awareness of facial deformity”, as well as total OQLQ score, after adjustment for demographic characteristics, skeletal parameters, anxiety and depression. The same analyses were performed for the SF-36 domains. None was found to be predictive (data not shown). Table 6. Predictive value of OQLQ domains for two different treatment options in the study of quality of life assessment in patients with malocclusion undergoing orthodontic and orthognathic treatment in Serbia. OQLQ domains OR* 95%CI p Social aspects 1.07 1.00–1.14 0.051 of deformity Facial 1.15 1.03–1.28 0.013 aesthetics Oral function 1.08 0.97–1.21 0.160 Awareness of 1.14 1.03–1.32 0.046 facial deformity Total OQLQ 1.04 1.00–1.07 0.020 *Adjusted for demographic characteristics, skeletal parameters, anxiety and depression 4 DISCUSSION This study demonstrates the existence of significant differences in the mean values of all OQLQ domain scores between orthodontic and orthognathic patients, except in the domain of “Awareness for facial deformity”. Patients for whom orthodontic treatment was planned had statistically significantly lower baseline OQLQ scores in comparison to those for whom orthognathic treatment was planned, suggesting that they enjoyed a better quality of life. On the other hand, there was no significant difference in mean OQLQ domain scores and total score between the orthognathic group of patients and those who had been refused orthognathic treatment. Additionally, independent predictors for the planning of orthodontic and orthognathic treatment in patients with malocclusion were two OQLQ domains, “Facial aesthetics” and “Awareness of facial deformity”, as well as total OQLQ score. The mean values for all OQLQ domains in the total cohort of our patients with malocclusion were lower than in previously published studies (10, 29-31). The data varies because of differences in study protocols and settings. Our findings are otherwise similar to those obtained in Cunningham’s study (10), but different to those in the study conducted by Bock et al. (30). While German patients’ complaints focused heavily on “Functional impairment” (30), those of Serbian patients focused on “Facial aesthetics”. Tajima et al. showed OQLQ domain scores for three different groups in a Japanese population (orthodontic group, orthognathic group, control group with normal occlusion). All those people focused their complaints on facial aesthetics in first place and on the social aspects of deformity in second place (29). These authors also showed similar results to ours in relation to the comparison between surgically treated and non-treated patients, namely a significant difference in OQLQ domain scores between these two groups (29). Results comparing quality of life before orthodontic and orthognathic treatment in patients with malocclusion are inconsistent (31-33). In the two recent studies referred to above (32, 33), quality of life was better or the same in the orthodontic treatment first group in comparison with the surgery first group. More recently, however, the contrary has been shown: in a group of 32 patients, those patients planned for surgery first had a lower total OQLQ score and social domain score than those planned for orthodontics first (31). In order to assess the reliability of the generic (SF-36) and specific (OQLQ) instruments in detecting differences in quality of life and when planning different therapeutic strategies for patients with malocclusion, we performed two independent logistic regression analyses. None of the SF-36 domains were found to be predictive. On the other hand, we demonstrated that OQLQ was more reliable and sensitive for the detection of differences in quality of life between different treatment options. Furthermore, it has to be mentioned that statistically significant correlations between SF-36 and PAR pre-treatment scores were not found, suggesting that malocclusion presence and severity did not influence general health-related QoL in our cohort. However, the correlation of OQLQ and PAR pre-treatment scores indicated that participants with more severe malocclusion had worse specific QoL, which accords with the notions presented by Sun et al. (34). In our survey, there was no statistically significant correlation with malocclusion severity, except with the domain of “Awareness of facial deformity”. Similar results are shown in the study by Struggle et al. (35). A statistically significant correlation between sagittal type of malocclusion and OQLQ scores was not found in our patients. Regarding intermaxillary angle, patients with low angle malocclusion presented with the most significantly impaired specific QoL, especially in “Social aspects of deformity”. Finally, in our cohort malocclusion severity had greater impact on malocclusion-specific QoL than the skeletal type of malocclusion, which is similar to the results obtained by Rusnan et al. in the Finnish population (36). We have also demonstrated that the domain of “Awareness of facial deformity” correlated significantly with maxillary retrognathism. Likewise, the domain of “Facial aesthetics” score correlated with both maxillary and mandibular retrognathism, suggesting that middle face concavity or a possible bird-like profile might be less acceptable in our population. Some limitations of the present study need to be kept in mind when interpreting the results. First, the choice of the questionnaire could be discussed. The Oral Health Impact Profile (OHIP) instrument is a widely used generic questionnaire for oral health quality of life (37). However, this questionnaire has unfortunately not yet been validated for Serbian cultural settlements. Another limitation is related to the design of the study, which was cross-sectional. A longitudinal study capable of following the evolution of quality of life after treatment would have been preferable. Quality of life has therefore recently been assessed using OQLQ in two groups of patients with dentofacial deformities after the orthodontic-first and orthognathic-first approach in 32 patients. It was shown that the mean OQLQ score and the individual domain scores showed significant improvements at six weeks and six months post-operatively (31). The strength of our study might be in the rather high number of study participants treated and followed-up at the national referral centre. We should emphasise that the number of adult patients seeking orthodontic care today is on the rise and that clinicians frequently face difficulties in achieving adequate therapeutic strategies, since in the majority of these cases both surgical and non-surgical treatment plans can be considered. In cases of significant skeletal malocclusion, the chance that orthodontic treatment alone (i.e. without surgery) will produce beneficial effects is small. However, especially in borderline cases, it would be crucial to define whether the difference in quality of life after intervention between surgical and non-surgical treatment is expected to be significant. Moreover, future studies that deal with quality of life changes after surgical or non-surgical treatment first could potentially provide data on predictive factors of treatment outcome. Finally, such quality of life data might be of interest to public oral health systems, as well as to health insurance companies and national health services, as one of the outcome measures. In conclusion, our patients for whom orthodontic treatment was planned demonstrated better quality of life according to their OQLQ scores than those planned for whom an orthognathic strategy was planned. The independent predictors for the planning of orthodontic and orthognathic treatment in patients with malocclusion were two OQLQ domains, “Facial aesthetics” and “Awareness of facial deformity”. All patients with malocclusion should be involved in the shared decision-making process related to the choice of treatment, after a detailed diagnostic procedure followed by a quality of life assessment using specific instruments. This could have a significant impact on the treatment strategy, at least in certain cases. CONFLICT OF INTEREST The authors declare that no conflicts of interest exist. FUNDING This study was supported by the Ministry of Education, Science and Technological Development of the Republic of Serbia (Grant nos 175031 and 175087). ETHICAL APPROVAL Received from the Ethical Committee of the Faculty of Dental Medicine of the University of Belgrade. REFERENCES 1. Alhammadi MS, Halboub E, Fayed MS, Labib A, El-Saaidi C. Global distribution of malocclusion traits: a systematic review. Dental Press J Orthod. 2018;23:40.e1-.e10. doi: 10.1590/2177-6709.23.6.40.e1-10.onl 2. Shaw W, Addy M, Ray C. Dental and social effects of malocclusion and effectiveness of orthodontic treatment: a review. Community Dent Oral Epidemiol. 1980;8:36-45. 3. Cunningham SJ, Hunt NP. Quality of life and its importance in orthodontics. J Orthod. 2001;28(2):152-8. doi: 10.1093/ortho/28.2.152. 4. Angle EH. Classification of malocclusion. Dental Cosmos. 1899;41:248­ 64. 5. 5.Brook PH, Shaw WC. The development of an index of orthodontic treatment priority. Eur J Orthod. 1989;11:309-20. 6. Richmond S, Shaw WC, O’Brien KD, Buchanan IB, Jones R, Stephens CD, et al. The development of the PAR Index (Peer Assessment Rating): reliability and validity. Eur J Orthod. 1992;14:125-39. 7. Chauca FB. Moving toward patient-centered orthodontics: patient-reported outcome measures. Am J Orthod Dentofacial Orthop. 2018;153:324. doi: 10.1016/j.ajodo.2017.11.021. 8. Tsakos G. Combining normative and psychosocial perceptions for assessing orthodontic treatment needs. J Dent Educ. 2008;72:876-85. 9. Cunningham SJ, Garratt AM, Hunt NP. Development of a condition- specific quality of life measure for patients with dentofacial deformity: I: reliability of the instrument. Community Dent Oral Epidemiol. 2000;28:195-201. 10. Cunningham SJ, Garratt AM, Hunt NP. Development of a condition- specific quality of life measure for patients with dentofacial deformity: II: validity and responsiveness testing. Community Dent Oral Epidemiol. 2002;30:81-90. 11. Benson PE, Cunningham SJ, Shah N, Gilchrist F, Baker SR, Hodges SJ, et al. Development of the Malocclusion Impact Questionnaire (MIQ) to measure the oral health-related quality of life of young people with malocclusion: part 2 – cross-sectional validation. J Orthod. 2016;43:14­ 23. doi: 10.1080/14653125.2015.1114223. 12. Patel N, Hodges SJ, Hall M, Benson PE, Marshman Z, Cunningham SJ. Development of the Malocclusion Impact Questionnaire (MIQ) to measure the oral health-related quality of life of young people with malocclusion: part 1 – qualitative inquiry. J Orthod. 2016;43:7-13. doi: 10.1080/14653125.2015.1114712. 13. Benson PE, Gilchrist F. The Malocclusion Impact Questionnaire (MIQ): Cross-sectional validation in a group of young people seeking orthodontic treatment in New Zealand. Dent J (Basel). 2019;7:e24. doi: 10.3390/dj7010024.2019;7(1). 14. Dimberg L, Arnrup K, Bondemark L. The impact of malocclusion on the quality of life among children and adolescents: a systematic review of quantitative studies. Eur J Orthod. 2015;37:238-47. doi: 10.1093/ ejo/cju046. 15. Javidi H, Vettore M, Benson PE. Does orthodontic treatment before the age of 18 years improve oral health-related quality of life?: a systematic review and meta-analysis. Am J Orthod Dentofacial Orthop. 2017;151:644-55. doi: 10.1016/j.ajodo.2016.12.011. 16. Al-Asfour A, Waheedi M, Koshy S. Survey of patient experiences of orthognathic surgery: health-related quality of life and satisfaction. Int J Oral Maxillofac Surg. 2018;47:726-31. doi: 10.1016/j.ijom.2017.12.010. 17. Zaror C, Pardo Y, Espinoza-Espinoza G, Pont A, Munoz-Millan P, Martinez-Zapata MJ, et al. Assessing oral health-related quality of life in children and adolescents: a systematic review and standardized comparison of available instruments. Clin Oral Investig. 2019;23:65­ 79. doi: 10.1007/s00784-018-2406-1. 18. Cunningham SJ, O’Brien C. Quality of life and orthodontics. Seminars in Orthodontics. 2007;13:96-103. doi: 10.1053/j.sodo.2007.03.005. 19. Felce D, Perry J. Quality of life: its definition and measurement. Res Dev Disabil. 1995;16:51-74. 20. Alanko OME, Svedström-Oristo A-L, Tuomisto MT. Patients’ perceptions of orthognathic treatment, well-being, and psychological or psychiatric status: a systematic review. Acta Odontol Scand. 2010;68:249-60. doi: 10.3109/00016357.2010.494618. 21. Penacoba C, González MJ, Santos N, Romero M. Psychosocial predictors of affect in adult patients undergoing orthodontic treatment. Eur J Orthod. 2013;36:93-8. doi: 10.1093/ejo/cjt007. 22. Cofre E, Rodríguez K. Impact of dentofacial esthetics in self-esteem: a review of the literature. Int J Med Surg Sci. 2018;5:22-7. doi: 10.32457/ ijmss.2018.007. 23. Ozerovic B. Rendgenokraniometrija i rendgenokefalometrija. Beograd: Stomatološki fakultet, 1985. 24. Ware JE, Sherbourne CD. The MOS 36-Item Short-Form Health Survey (SF-36): I: conceptual framework and item selection. Med Care. 1992;30:473-83. 25. Vucic L, Glisic B, Kisic-Tepavcevic D, Vucic U, Drulovic J, Pekmezovic T. Cross-cultural adaptation and validation of the disease specific questionnaire OQLQ in Serbian patients with malocclusions. Zdr Varst. 2016;55:166-73. doi: 10.1515/sjph-2016-0021. 26. Beck AT, Ward C, Mendelson M, Mock J, Erbaugh J. Beck depression inventory (BDI). Arch Gen Psychiatry. 1961;4:561-71. 27. Beck AT, Epstein N, Brown G, Steer RA. An inventory for measuring clinical anxiety: psychometric properties. J Consult Clin Psychol. 1988;56:893-7. 28. Rosenberg M. Society and the adolescent self-image. Princeton: University Press, 1965. 29. Tajima M, Kohzuki M, Azuma S, Saeki S, Meguro M, Sugawara J. Difference in quality of life according to the severity of malocclusion in Japanese orthodontic patients. Tohoku J Exp Med. 2007;212:71-80. 30. Bock JJ, Odemar F, Fuhrmann RA. Assessment of quality of life in patients undergoing orthognathic surgery. J Orofac Orthop. 2009;70:407-19. doi: 10.1007/s00056-009-9903-4. 31. Saghafi H, Benington P, Ayoub A. Impact of orthognathic surgery on quality of life: a comparison between orthodontics-first and surgery-first approaches. Br J Oral Maxillofac Surg. 2020;58:341-7. doi: 10.1016/j.bjoms.2020.01.005 32. Pelo S, Gasparini G, Garagiola U, et al. Surgery-first orthognathic approach vs traditional orthognathic approach: oral health-related quality of life assessed with 2 questionnaires. Am J Orthod Dentofacial Orthop. 2017;152:250-4. doi: 10.1016/j.ajodo.2016.12.022. 33. Brucoli M, Zeppegno P, Benech R, et al. Psychodynamic features associated with orthognathic surgery: a comparison between conventional orthognathic treatment and “surgery-first” approach. J Oral Maxillofac Surg. 2019;77:157-63. doi: 10.1016/j.joms.2018.06.005. 34. Sun L, Wong HM, McGrath CPJ. Association between the severity of malocclusion, assessed by occlusal indices, and oral health related quality of life: a systematic review and meta-analysis. Oral Health Prev Dent. 2018;16:211-23. doi: 10.3290/j.ohpd.a40761. 35. Stagles C, Popat H, Rogers S. Factors influencing patient-reported quality of life in pretreatment orthognathic surgery patients. Angle Orthod. 2016;86:331-6. doi: 10.2319/030415-132.1. 36. Rusanen J, Lahti S, Tolvanen M, Pirttiniemi P. Quality of life in patients with severe malocclusion before treatment. Eur J Orthod. 2010;32:43­ 8. doi: 10.1093/ejo/cjp065. 37. Slade GD, Spencer AJ. Development and evaluation of the oral health impact profile. Community Dent Health. 1994;11:3-11. FEAR OF RELATIONSHIP LOSS: ATTACHMENT STYLE AS A VULNERABILITY FACTOR IN JOB BURNOUT STRAH PRED IZGUBO ODNOSA: STIL NAVEZANOSTI KOT DEJAVNIK RANLJIVOSTI ZA IZGOREVANJE NA DELOVNEM MESTU Andreja PŠENICNY1*, Mitja PERAT1 1Institute for Human Resource Development, Psychotherapy, Gasilska 19, 1000 Ljubljana, Slovenia Received: Feb 11, 2020 Accepted: May 19, 2020 ABSTRACT Keywords: burnout, wornout, performance-based self-esteem, workaholism, attachment styles IZVLECEK Kljucne besede: izgorelost, delovna izcrpanost, storilnostno samovrednotenje, deloholizem, stili navezanosti Original scientific article Objective: To investigate the correlation between attachment styles and various burnout risk groups (“relaxed”, “wornout”, “challenged” and “burnout”) and whether attachment styles suitably discriminate between individual burnout risk groups. Method: The study involved 2,320 participants (1,668 women and 652 men), who completed an adrenal burnout syndrome questionnaire, a performance-based self esteem scale, a work addiction risk test and a relationship questionnaire. Results: A one-way analysis of variance confirmed attachment style differences between burnout risk groups. The challenged and burnout groups differed from the relaxed and wornout groups by having a significantly lower secure attachment style score and a higher insecure (avoidant and preoccupied) attachment style score. The canonical discriminant analysis showed that the predictors (secure, preoccupied and avoidant attachment styles) can be used to appropriately classify 85.4% of respondents in the predicted burnout risk groups. Conclusion: The study confirmed the hypothesis that two insecure attachment styles (i.e. avoidant and preoccupied) predominate in the challenged and burnout groups, and that a secure attachment style predominates in the relaxed and wornout groups. Burnout syndrome can thus be conceived as the result of excessive and compulsive efforts to retain a relationship that is perceived as insecure or to reduce (excessive) fear of losing this relationship. Namen: Ugotavljali smo, kako se stili navezanosti povezujejo z razlicnimi skupinami tveganja za izgorelost (neogroženi, delovno izcrpani, kandidati, izgoreli) in ali stili navezanosti ustrezno diskriminirajo med skupinami ogroženosti za izgorelost. Metoda: V raziskavi je sodelovalo 2320 udeležencev (1668 žensk, 652 moških), ki so izpolnili vprašalnik sindroma adrenalne izgorelosti, vprašalnik storilnostno pogojenega samovrednotenja, vprašalnik deloholizma ter vprašalnik stila navezanosti. Rezultati: Z enosmerno analizo variance smo potrdili razlike v stilih navezanosti med skupinami ogroženosti za izgorelost. Kandidati za izgorelost in izgoreli so se od neogroženih in delovno izcrpanih po stilu izgorelosti razlikovali, tako da so dosegli pomembno nižjo oceno varnega stila navezanosti in hkrati višjo oceno nevarnih stilov navezanosti (izogibajocega in preokupiranega). S kanonicno diskriminantno analizo smo ugotovili, da se glede na prediktorje (varen, preokupiran in izogibajoc stil navezanosti) 85,4 odstotka udeležencev ustrezno razvršca v predpostavljene skupine ogroženosti za izgorelost. Sklep: Raziskava je potrdila domnevo, da pri kandidatih in izgorelih prevladujeta dva nevarna stila navezanosti (izogibajoci in preokupirani), medtem ko pri neogroženih in delovno izcrpanih prevladuje varni stil navezanosti. Izgorevanje in izgorelost lahko torej razumemo kot posledico pretiranega, kompulzivnega prizadevanja, da bi ohranili odnos, ki ga doživljajo kot nevarnega, in tako ublažili svoj (pretirani) strah pred izgubo tega odnosa. *Corresponding author: Tel. + 386 31 711 421; E-mail: apsenicny@burnout.si © National Institute of Public Health, Slovenia. 1 INTRODUCTION 1.1 Burnout and Wornout Burnout can be conceived of as a process resulting from unsuccessful (workaholic) efforts to maintain a stable self-image through achievements, which are a component part of one’s self-esteem. Burnout is a decompensation, which is the final result of the process of self-exhaustion through overcompensated activity (1). “Wornout” is an expression denoting a feeling of cognitive and physical exhaustion, and emotional reactions to this condition without the associated signs of anxiety and fear (2), or exhaustion that does not result from attempts to create or maintain self-esteem (3). In terms of burnout risk, a distinction can be made between the following four groups: “relaxed”, “challenged”, “wornout” and “burnout”. Hallsten et al. (3) distinguished between these groups based on the following two criteria: a high or low level of burnout and high or low performance-based self-esteem. Pšenicny and Perat (4) in turn use three criteria: a high or low level of burnout, high or low performance-based self-esteem, and workaholism. Table 1. Burnout risk groups. Low Relaxed Challenged High Wornout Burnout Compulsive motivation that ultimately leads to exhaustion and burnout originates from a deficit in self-esteem that is labile and dependent on achievements and external validation (performance-based self-esteem). The fear of losing self-esteem can be so strong that it leads to excessive working (and emotional) over-investment. This over-investment is also an indicator of poorer self-regulation when it exceeds all limits and hard work is replaced by its compulsive form (i.e. workaholism), which ultimately poses a threat to physical and mental health. These two traits, which may also indicate a personality disorder in most individuals at risk of burnout, can therefore be considered a risk factor for the development of burnout syndrome. These risk-posing traits are only weakly expressed in relaxed and wornout individuals (4). 1.2 Attachment Styles and Fear of Relationship Loss In his attachment theory, Bowlby (5, 6) explains that feelings of (in)security are the consequence of (un) successful interactions between a child and his/her primary caregiver (most often the mother). These repeating patterns of behaviour in interaction with the caregiver transform into mental representations. These specific mental representations are referred to as attachment styles, which constitute one’s basic mental model for understanding the social world. Moreover, an attachment style is an implicit and automated method of organising stimuli. However, it is subject to perceptual and cognitive errors. Bartholomew and Horowitz (7) empirically validated four attachment styles and categorised them into a secure attachment style (representations of both the self and the other are predominantly positive) and three insecure attachment styles: a preoccupied attachment style (a negative representation of self and a positive representation of the other), a fearful-avoidant attachment style (the representations of self and of the other are relatively negative) and a fearful-dismissing attachment style (the representation of self is positive and the representation of the other is negative). Adult attachment styles and mental representations both influence the formation of the models of self, of other and of relationships with others - that is, they also influence the (subconscious) expectations about relationships with others and our understanding of the social environment. Individuals with an implicit insecure attachment style in general experience relationships as less secure and stable (8, 9). According to the sociometer theory (10), threats to one’s relational value, such as social rejection, exclusion and criticism, are the most acute modern-day stressors because they undermine the feeling of social value, esteem and status (11). Research confirms the correlation between social stressors and job burnout (12), between burnout and hypersensitivity to rejection and criticism (4), and between an insecure attachment style and hypersensitivity to rejection and abandonment as a predictor of burnout (13). 1.3 Attachment Style, Regulation of Stress Response and Work Environment Early experiences of secure or insecure emotional attachment play a crucial role in the development of an individual’s personality. Among other things, they are key to an individual’s ability to regulate emotions and cope with stressful situations, and have a significant effect on how an individual responds to the threat of losing an important attachment object (14). The experience of insecure attachments results in a higher level of neuroticism or a generally weaker ability to regulate stress responses (15), and in various forms of personality traits that increase personal vulnerability, such as perfectionism, emotional lability, etc. (16) and workaholism (1, 17). Compared to those with an insecure attachment style, employees with a secure attachment style express higher general satisfaction, enjoy their work more, and are less worried about relationships at work. They experience less stress and cope with it more successfully, create a better work-life balance, and know how to seek help. Insecurely attached individuals are more afraid of rejection and poor performance, tend to be more over-involved, and feel less important and valued at work. Some avoid social contact (18-21). Several studies have confirmed a correlation between attachment styles and stress and burnout at work. Their authors report a negative correlation between a secure attachment style and burnout symptoms, and positive correlations between burnout and insecure attachment styles (i.e. preoccupied and avoidant) (15, 22-24). These correlations are understandable because people become attached to their work and the workplace, as well as to the people they encounter in this important living environment. The same notions and emotional responses, including expectations and fears, as exist in any other attachment relationship therefore come to the fore within this social context. Hence, for most people work and the work environment are important sources of security or insecurity. People who grew up experiencing insecure attachment, however, have at-risk personality traits that, in certain conditions, drive them into a process of exhaustion and may increase their work-related or other engagements endlessly (1, 4). 2 RESEARCH PROBLEM We explored whether the relaxed and wornout groups differ from the challenged and burnout groups in terms of attachment style. 2.1 Hypotheses This study’s basic premise was that insecure attachment affects the development of traits that pose a risk of burnout (i.e. performance-based self-esteem and workaholism). Individuals with a higher level of at-risk traits were therefore also expected to have more pronounced insecure attachment styles. The following working hypotheses can be specified based on these premises: H1a: The average score on various attachment styles (secure, preoccupied, avoidant and dismissing) differs significantly by burnout risk group (independent variable: relaxed, challenged, wornout and burnout). H1b: A significant correlation is expected between various attachment styles (secure, preoccupied, avoidant and dismissing) and burnout risk groups (relaxed, challenged, wornout and burnout). H2: The set of attachment styles (secure, preoccupied, avoidant and dismissing) produces a suitable distinction between the burnout risk groups. 3 METHOD 3.1 Participants and Instruments 3.1.1 Participants The convenience sample included participants that completed the questionnaires posted on the website of the Institute for Human Resource Development between January 2018 to April 2019. A total of 2,320 individuals (1,668 women and 652 men) completed the questionnaires. Fourteen per cent of them were unemployed (including students and seniors), 69% were in employment, 7% were self-employed and 10% held managerial positions. The youngest respondent was 18 years old and the oldest was 69 (M=38.50, SD=11.33). 3.1.2 Instruments The Adrenal Burnout Syndrome Questionnaire or ABSQ (25) comprises four scales: body symptoms (45 items), emotional symptoms (94 items), behavioural symptoms (61 items) and cognitive symptoms (46 items). Cronbach’s a=0.962. The outcomes are the variable “average adrenal burnout syndrome rate” or ABSRa (with scores from 0 to 3), hereinafter referred to as “burnout,” and the categorical variable “burnout classes” or ABSCl (0=no symptoms; 1=mild; 2=medium; 3=strong burnout). The latter was further converted into the dichotomous variable “burnout categories” or ABSCat (low level=no symptoms; high level=1, 2, 3). The participants were then further divided into four burnout risk groups, whereby the variable “risk” (ABSRi) was obtained. The classification procedure is described below under “H1 testing.” The Performance-Based Self-Esteem Scale or PBSE Scale (3) comprises four statements and measures performance- based self-esteem. The responses were rated on a five- point Likert scale (1=Fully disagree, 2=Somewhat disagree, 3=Neither agree nor disagree, 4=Somewhat agree, 5=Fully agree). The questionnaire’s reliability measured using Cronbach’s alpha was 0.872. The outcome is the variable “average test score” or, as we called it, “performance­based self-esteem” or PBS (with scores from 1 to 5). This variable was further converted into the dichotomous variable “performance-based self-esteem categories” or PBSCat (low level=1-2.45; high level =2.46-5). The criterion used was the average score reported by the authors of this scale. The Work Addiction Risk Test or WART (26) comprises 25 items and measures the tendency for compulsive hard work or workaholism. Cronbach’s a=0.966. The responses 10.2478/sjph-2020-0019 were rated on a four-point Likert scale (1=Never true, 2=Sometimes true, 3=Often true, 4=Always true). The outcome of the test is the variable “workaholism” or WORKHL (with scores ranging from 25 to 100). The average score reported by Robinson is 47, which was used as the criterion for converting this variable into the dichotomous variable “workaholism categories” or WORKCat (low level: 25-47; high level=48-100). Based on the results of these three questionnaires, the respondents were divided into four burnout risk groups: relaxed, challenged, wornout and burnout. Three classification criteria were used: a low or high level of burnout (ABSCat), low or high performance-based self-esteem (PBS Cat), and a low or high level of workaholism (WORKCat), as the last two variables are the main predictors of burnout (1). The variable “risk” (ABSRi) was thus obtained, with four groups of respondents at various risk of burnout: the relaxed group (a low level of performance-based self-esteem, workaholism and burnout), challenged (a high level of performance-based self-esteem and/or workaholism and/or a low level of burnout), the wornout group (a low level of performance-based self-esteem and workaholism, and a high level of burnout), and the burnout group (a high level of performance-based self-esteem and/or workaholism and burnout). The Relationship Questionnaire or RQ (7) comprises four short paragraphs describing a prototypical attachment pattern as it applies in close adult peer relationships (Bartholomew & Horowitz, 1991). Participants first select (forced choice) one of the four attachment styles (secure, preoccupied, avoidant and dismissing) and then rate each one on a seven-point Likert scale. These scores form the profile of an individual’s attachment style. The outcome is the categorical variable “attachment style” (STYLE) and four continuous variables: “secure attachment style” (SEC­AS), “preoccupied attachment style” (PRE-AS), “avoidant attachment style” (AVO-AS), and “dismissing attachment style” (DIS-AS; scores for all these ranging from 1 to 7). Zdr Varst. 2020;59(3):146-154 The last four variables were combined into an aggregate variable “attachment styles” (ASTYLES). 3.2 Procedure The PBSE scale and WART test were translated into Slovenian by Andreja Pšenicny and Mitja Perat with the author’s permission, after which they were back-translated by an English specialist. Participants completed the questionnaires posted on the website of the Institute for Human Resource Development between January 2018 and April 2019. Their personal data was protected in accordance with the Slovenian Personal Data Protection Act. 4 RESULTS 4.1 Descriptive Sample Statistics Table 2. Descriptive statistics for the testing results (mean scores and standard deviations). Burnout (ABSRa) 0.65 0.72 Performance-based self-esteem (PBS) 34.21 14.09 Workaholism (WORKHL) 56.59 17.98 Secure style (SEC-AS) 4.12 2.19 Preoccupied style (PRE-AS) 3.29 2.05 Avoidant style (AVO-AS) 3.63 2.24 Dismissing style (DIS-AS) 3.59 2.01 Attachment styles by category (forced choice): the secure attachment style was selected by 31.1% of participants, the preoccupied style by 19.3%, the avoidant by 27.5% and the dismissing by 22%. The differences were statistically significant (.2 (3)=79.02, p<0.01) The differences in the test scores between the low- and high-level categories (see the Methods section for the variables used) are shown in Table 3. Table 3. Frequencies, descriptive statistics and differences in test scores by category “low level” and “high level” for burnout, performance-based self-esteem and workaholism. N MSD t t-test df p ABSCat Low 1,130 0.06 0.11 -66.19 1778.04 0.00** High 1,190 1.22 0.58 PBSCat Low 431 1.69 0.41 -60.15 120.50 0.00** High 2,694 3.74 0.66 WORKCat Low 335 37.84 7.28 -41.21 133.521 0.00** High 1,225 67.85 12.77 **Statistically significant difference p<0.01 Notes: ABSCat=adrenal burnout syndrome categories; PBSCat=performance-based self-esteem categories; WORKCat=workaholism categories Based on the results shown in Table 3, participants were divided into four burnout risk groups. Table 4 shows the descriptive statistics for the selected parameters by individual ABSRi category. Table 4. Descriptive statistics (mean scores and standard deviations) for performance-based self-esteem, workaholism and burnout by burnout risk group (ABSRi), and the results of the one-way analysis of variance. F MM df(3.3389) p Performance-based self-esteem Relaxed Challenged Wornout Burnout 19.16 41.55 20.49 43.82 5.60 10.50 4.47 9.11 1,489.78 0.00** Workaholism Relaxed Challenged Wornout Burnout 39.24 63.37 44.50 67.47 8.91 17.46 7.22 13.75 712.45 0.00** Burnout Relaxed Challenged Wornout Burnout .03 .03 .81 1.29 .08 .02 .29 .60 1,686.04 0.00** **Statistically significant difference p<0.01 Table 5 shows the final classification of participants into ABSRi categories. Table 5. Participant classification into burnout risk groups (ABSRi variable). Low PBSCat Relaxed Wornout and WORKCa 832 (35.9%) 328 (14.1%) High PBSCat Challenged Burnout and WORKCat 258 (11.1%) 902 (38.9%) Notes: ABSCat=adrenal burnout syndrome categories; PBSCat=performance-based self-esteem categories; WORKCat=workaholism categories 4.2 H1 Testing Proceeding from the assumption that an insecure attachment style is associated with burnout risk, the challenged and burnout group ought to have a higher score for insecure attachment styles (preoccupied, avoidant and dismissing) and a lower secure attachment style score than the relaxed and wornout groups. To check this, we carried out a repeated measures analysis of variance. Because Mauchly’s test showed that sphericity (.2(2)=189.60, p<0.01) was violated, we corrected the degrees of freedom using Greenhouse–Geisser sphericity estimates. Comparison of attachment style mean scores (secure, preoccupied, avoidant and dismissing) between burnout risk groups (relaxed, challenged, wornout and burnout). Table 6. Summary of one-way repeated measures analysis of variance: attachment style mean score (ASTYLES variable) by group (relaxed, challenged, wornout and burnout; (ABSRi variable). Variability source SS df MS F p Between individuals Cross section 464.632 3 154.877 56.215 0.00** Error 6,380.744 2,316 2.755 Within individuals ASTYLES 1,482.684 2.627 564.354 108.028 0.00** ASTYLES*ABSRi 3321.341 7.882 421.400 80.664 0.00** Error 31,787.110 6,084.654 5.224 **Statistically significant difference p<0.01 The results confirmed our hypothesis for two insecure attachment styles (i.e. preoccupied and avoidant) and the secure attachment style. The challenged and burnout group showed a significantly lower secure attachment style score and a significantly higher score for two insecure attachment styles (i.e. preoccupied and avoidant) than the relaxed and wornout (Figure 1, Table 6). A post-hoc comparison of difference also shows no statistically significant differences between the relaxed and wornout groups in any attachment style. The dismissing attachment style is significantly lower among the relaxed group than among the burnout group (p<0.05), whereas no significant differences in this style can be observed between the other groups. The first part of the hypothesis that burnout risk groups also differ by the degree of expression of secure and insecure attachment styles can be confirmed for the secure and two insecure attachment styles (i.e. preoccupied and avoidant), whereas it can only partly be confirmed for the dismissing style. If it is primarily insecurely attached individuals who burn out, one would expect a considerably higher percentage of those that chose an insecure attachment style among the challenged and burnout group than among the relaxed and wornout groups. As anticipated, more than a half of the relaxed and wornout individuals reported a secure attachment style, whereas only one-fifth reported the same among the challenged, and only every thirtieth among the burnout group. The avoidant attachment style predominated in these two groups (Table 7). The differences were statistically significant (.2(9)=1,208.619, p<0.01). Based on this, the second part of the hypothesis can also be confirmed. Table 7. Comparison of the percentage of participants with secure and insecure attachment styles (ASTYLES variable) between burnout risk groups (ABSRi variable). Attachment styles (ASTYLES) Secure Preoccupied Avoidant Dismissing Burnout risk groups Relaxed N 446 56 34 296 % 53.6% 6.7% 4.1% 35.6% Challenged N 53 49 102 54 % 20.5% 19.0% 39.5% 20.9% Wornout N 193 48 15 72 % 58.8% 14.6% 4.6% 22.0% Burnout N 30 295 488 89 % 3.3% 32.7% 54.1% 9.9% Note: No cells (0.0%) have an expected number below 5. The minimum expected number is 49.82 4.3 H2 Testing In the final stage, we also explored whether the set of attachment styles studied also enabled appropriate classification of participants into the burnout risk groups defined based on three criteria (i.e. performance-based self-esteem, workaholism and burnout). A canonical discriminant analysis with a gradual inclusion of variables was used. The variable “dismissing attachment style” (DIS-AS) was excluded from the analysis. Table 8. Testing the equality of centroids by burnout class (ABSCl). 1 / 3 0.12 4,921.07 12 0.00** 2 / 3 0.80 507.64 6 0.00** 3 0.95 11.53 2 0.00** **Statistically significant difference p<0.01 All three functions are statistically significant (Table 8). The first function is moderately positively correlated with the preoccupied and avoidant attachment styles. The second function is very strongly positively correlated with secure attachment, and the third function is very strongly positively correlated with the remaining predictors, with the preoccupied style being inversely proportionate to this function (Table 9). Based on these three predictors, originally 85.4% of participants were classified into appropriate burnout risk groups (Table 10). The third hypothesis can thus be confirmed. 5 DISCUSSION Like many previous studies, this study also confirmed that individuals who developed insecure attachment styles due to specific circumstances during their childhood burn out more often and more strongly than those that were securely Table 9. Relative influence of predictors on the functions’ values (standardised coefficients) and the correlation between the “ASTYLES” variables and functions (structural matrix). Standardised coefficients Structural matrix Functions Functions 12 3 12 3 Secure style -0.42 -0.92 0.15 -0.38 0.92* -0.05 Preoccupied style 0.88 0.35 -0.61 0.34 0.31 -0.85* Avoidant style 0.94 0.40 0.47 0.57 0.12 0.78* Dismissing style -0.03 0.06 0.27 -0.00 -0.01 0.41* *Maximum absolute correlations between each variable and individual discriminant function Table 10. Percentages of appropriately classified members of individual burnout risk groups. Predicted group members Relaxed Challenged Wornout Burnout Original group Relaxed 86.3% 4.1% 9.6% 0.0 members Challenged 0.0 91.1% 8.9% 0.0 Wornout 0.0 10.7% 89.3% 0.0 Burnout 0.0 15.9% 2.7% 81.5% attached to their parents or caregivers. The new finding presented in this study is that a distinction can also be made between the wornout and burnout individuals based on their attachment styles. What the burnout and wornout groups have in common is a general feeling of overtiredness and exhaustion, but unlike the burnout group, the wornout do not show any significant psychopathological characteristics and symptoms (3, 4) argue that performance-based self-esteem is the psychopathological characteristic that distinguishes the wornout from the burnout. Pšenicny and Perat (4) also added workaholism as the third criterion. The same criteria are used to distinguish between the relaxed and the challenged. Due to these risky personality traits, we consider the “challenged” to be potential candidates for burnout. The study confirmed the hypothesis that a secure attachment style predominated among wornout and relaxed individuals and that insecure attachment styles were more common among the burnout and challenged. In addition, attachment styles proved to be an important predictor for classifying participants into these four categories (over 85% of participants were appropriately classified). Even in more strenuous and stressful circumstances, more securely attached individuals will experience only (normal) signs of exhaustion (wornout). Unlike burnout, this does not lead to decompensation because these individuals will not neglect their needs due to excessive fear of losing an important relationship. In our opinion, securely attached individuals will respond reciprocally: they will take criticism, rejections and threats into consideration, and increase their investment only to a reasonable extent because they are able to emotionally cope with potential loss. In individuals with preoccupied and avoidant attachment styles, the fear of losing an important relationship, including interpersonal relationships at work and employment itself, may be such a strong stressor that it can function as compulsive motivation and trigger over-investment (workaholism) or a search for constant validation through performance (performance-based self-esteem) with a single goal in mind: to retain this relationship. Adverse psychological as well as objective work circumstances and inappropriate interpersonal relationships in the workplace can be a real trigger for this fear for all employees, except that it is disproportionately strong in those who carry an insecure attachment style and triggers defensive over-engagement. Burning out and burnout can thus be conceived as the result of excessive and compulsive efforts to retain a relationship that is perceived as insecure, or to reduce (excessive) fear of losing this relationship. Because the burnout group shows characteristics indicating the presence of psychopathological factors, and hence differs from the wornout group in this regard, this finding should be taken into account in selecting measures for preventing and treating these conditions. In addition to measures aimed at improving work conditions and acquiring more suitable skills and knowledge (which can successfully reduce wornout), individuals who are burning out also require professional help. Long-term (development-oriented) psychotherapy has a beneficial effect on changing a person’s attachment style by simultaneously and inversely proportionately increasing the secure attachment style and reducing insecure attachment (27). Various forms of training, coaching and counselling, as well as shorter forms of therapy (e.g. cognitive behavioural therapy) may also be helpful for managing the symptoms and constructing short-term coping strategies for better functioning in difficult work situations. This information is also important for employers in managing burnout. Specifically, burnout risk can be reduced in individuals identified as challenged (burnout candidates) by taking into account their specific vulnerabilities and taking appropriate action, increase their feelings of secure employment and decrease burnout triggers. 5.1 Limitations This study’s limitations lie in the unrepresentative nature of the sample and the instruments used. The convenience sample included in the study does not necessarily reflect the percentage of burnout, wornout and challenged individuals within a population. The Relationship Questionnaire used has its own limitations, particularly in terms of the validity of its content. Therefore, it cannot be used reliably in clinical practice. 6 CONCLUSION The study confirmed the hypothesis that two insecure attachment styles (i.e. avoidant and preoccupied) predominate in the challenged and burnout groups, and that a secure attachment style predominates in the relaxed and wornout groups. Burnout syndrome can thus be conceived as the result of excessive and compulsive efforts to retain a relationship that is perceived as insecure or to reduce (excessive) fear of losing this relationship. CONFLICTS OF INTEREST The authors have no conflicts of interest to declare. FUNDING The study was financed by the Institute for Human Resource Development, Ljubljana. ETHICAL APPROVAL Data confidentiality: Data was collected anonymously through the website. Informed consent and volunteering: Participants were informed in writing of the purpose of the survey and that they agreed to the use of their survey data by completing the questionnaires. The research carried no risk of the violation of ethical principles. REFERENCES 1. Pšenicny, A. Reciprocni model izgorelosti: povezava med interpersonalnimi in intrapersonalnimi dejavniki nastanka sindroma izgorelosti: doctoral dissertation. Ljubljana: University of Ljubljana, 2009. 2. Cox T, Kuk G, Leiter M. Burnout, health, work stress, and organizational healthiness. In: Schaufeli WB, editor. Professional burnout: recent developments in theory and research. Philadelphia, PA: Taylor & Francis, 1993:177-93. 3. Hallsten L, Josephson M, Torgén M. Performance-based self-esteem: a driving force in burnout process and its assessment. Arbete och Hälsa. 2005;4:117-39. 4. Pšenicny A, Perat M. Can burnout result from personality disorders? Anthrophos. 2016;1-2:27-49. 5. Bowlby J. Attachment and loss. Volume II. Separation: anger and anxiety. New York: Basic Books, 1973. 6. Bowlby J. A secure base: parent-child attachment and healthy human development. New York: Basic Books, 1988. 7. Bartholomew K, Horowitz L. Attachment styles among young adults: a test of a four-category model. J Pers Soc Psychol. 1991;61:226-44. doi: 10.1037/0022-3514.61.2.226. 8. Byrne Z, Albert L, Manning S, Desir R. Relational models and engagement: an attachment theory perspective. J Manag Psychol. 2017;32:30-44. doi: 10.1108/JMP-01-2016-0006. 9. Fraley R, Waller N, Brennan, K. An item response theory analysis of self-report measures of adult attachment. J Pers Soc Psychol. 2000;78:350-65. doi: 10.1037/0022-3514.61.2.226. 10. Leary M, Tambor E, Terdal S, Downs D. Self-esteem as an interpersonal monitor: the sociometer hypothesis. J Pers Soc Psychol. 1995;68:518­ 30. doi: 10.1037/0022-3514.68.3.518. 11. Dickerson S, Keneny M. Acute stressors and cortisol responses: a theoretical integration and synthesis of laboratory research. Psychol Bull. 2004;130:355-91. doi: 10.1037/0033-2909.130.3.355. 12. Dormann C, Zapf D. Customer-related social stressors and burnout. J Occup Health Psychol. 2004;9:61-82. doi: 10.1037/1076-8998.9.1.61. 13. Ronen S, Baldwin M. Hypersensitivity to social rejection and perceived stress as mediators between attachment anxiety and future burnout: a prospective analysis. Appl Psychol. 2010;59:380-403. doi: 10.1111/ j.1464-0597.2009.00404. 14. Shore J, Shore A. Modern attachment theory: the central role of affect regulation in development and treatment. Clin Soc Work J. 2007;36:9­ 20. doi: 10.1007/s10615-007-0111-7. 15. Pines AM. Adult attachment styles and their relationship to burnout: a preliminary, cross-cultural investigation. Work & Stress. 2004;18:66­ 80. doi. 10.1080/02678370310001645025. Zdr Varst. 2020;59(3):146-154 16. Lorente L, Salanova M, Martinez I, Schaufeli W. Extension of the job demands-resources model in the prediction of burnout and engagement among teachers over time. Psicothema. 2008:345-60. 17. Guglielmi D, Simbula S, Schaufeli W, Depolo M. Self-efficacy and workaholism as initiators of the job demands-resources model. Career Dev Int. 2012;17:375-89. doi: 10.1108/13620431211255842. 18. Hazan C, Shaver P. Love and work: an attachment-theoretical perspective. J Pers Soc Psychol. 1990;59:270-80. doi: 10.1037/0022­3514.59.2.270. 19. Harms P. Adult attachment styles in the workplace. Hum Resource Manage Rev. 2011;21:285-96. doi: 10.1016/j.hrmr.2010.10.006. 20. Richards D, Schat A. Attachment at (not to) work: applying attachment theory to explain individual behavior in organizations. J Appl Psychol. 2011;96:169-82. doi: 10.1037/a0020372. 21. Meredith P, Poulsen A, Khan A, Handerson J, Castrisos V. The relationship between adult attachment styles and work-related self-perceptions for Australian paediatric occupational therapists. Br J Occup Ther. 2011;74:160-7. doi: 10.4276%2F030802211X13021048723138. 22. Allison LW. Associations among attachment style, burnout, and compassion fatigue in health and human service workers: a systematic review. J Hum Behav Soc Environ. 2015:571-90. doi: 10.1080/10911359.2014.988321 23. Pickar S. How attachment style correlates to symptoms of burnout for direct care staff in a company that serves people with developmental and/or intellectual disabilities: master’s thesis. Saint Paul, MN: Hamline University, 2015. 24. Vîrga D, Schaufeli W, Taris T, van Beek I, Sulea C. Attachment styles and employee performance: the mediating role of burnout. J Psychol. 2019;153:383-401. doi: 10.1080/00223980.2018.1542375. 25. Pšenicny A. Razvoj vprašalnika sindroma adrenalne izgorelosti (SAI) in preverjanje izhodišca Reciprocnega modela izgorelosti. Psihološka Obzorja. 2007:47-82. 26. Robinson BE. (2014). Chained to the desk: a guidebook for workaholics, their partners and children and the clinicians who treat them. New York: University Press, 2014. 27. Buchheim A, Horz-Sagstetter S, Doering S, Rentrop M, Schuster P, Buchheim P, et al. Change of unresolved attachment in borderline personality disorder: RCT study of transference-focused psychotherapy. Psychother Psychosom. 2017;86:314-6. doi:10.1159/000460257. VALIDATION OF THE CROATIAN VERSION OF THE SENSE OF COHERENCE 29-ITEM SCALE IN CROATIAN NURSES OVREDNOTENJE HRVAŠKE VERZIJE DOLGEGA VPRAŠALNIKA O OBCUTKU KOHERENTNOSTI (SOC-29) PRI MEDICINSKIH SESTRAH Martina SMREKAR1,2, Lijana ZALETEL-KRAGELJ3, Olivera PETRAK1, Alenka FRANKO3,4* 1University of Applied Health Sciences Zagreb, Mlinarska cesta 38, 10000 Zagreb, Croatia 2University of Ljubljana, Faculty of Medicine, Zaloska 4, 1000 Ljubljana, Slovenia 3University of Ljubljana, Faculty of Medicine, Chair of Public Health, Zaloska 4, 1000 Ljubljana, Slovenia 4University Medical Centre Ljubljana, Clinical Institute of Occupational Medicine, Poljanski nasip 58, 1000 Ljubljana, Slovenia Received: Dec 19, 2019 Accepted: May 26, 2020 ABSTRACT Keywords: Sense of Coherence, SOC-29 instrument, validity, reliability, occupational medicine, nurses IZVLECEK Kljucne besede: obcutek koherentnosti, SOC-29, veljavnost, zanesljivost, medicina dela, medicinske sestre Original scientific article Introduction: The aim of the study was to validate the Croatian version of the Sense of Coherence 29-item instrument (SOC-29) within a nursing population. Methods: The cross-sectional study was conducted between December 2017 and June 2018 at the University Hospital Centre Sisters of Mercy (UHCSM) in Zagreb, Croatia. A total of 711 nurses participated in this study. Internal consistency reliability was evaluated using Cronbach’s alpha coefficient (a), while the structure of the questionnaire was verified by exploratory factor analysis (EFA) (method of extraction: principal component analysis (PCA)) and confirmatory factor analysis (CFA). Results: The instrument demonstrated high internal consistency (a=0.885). PCA analysis has identified five factors that together account for 48% of the variance. However, the observed factors could not be interpreted. In the CFA, none of the models fitted well, although the fit of the three-factor model (CMIN/DF=4.786, CFI=0.767, RMSEA=0.073) was slightly better in comparison with the one-factor model (CMIN/DF=6.072, CFI=0.685, RMSEA=0.084). As the three-factor model in PCA has been shown to be uninterpretable, and all three factors were mutually positive and significantly correlated (correlation coefficients: 0.365-0.521), this indicated a single factor in the background. All items also showed saturation with the first factor (accounting for 25.7% of the variance). Conclusions: The Croatian version of the SOC-29 instrument successfully fulfilled the necessary psychometric criteria for being used on the population of Croatian nurses. The study proposes that potential users use the single-factor structure. Uvod: Želeli smo ovrednotiti, ali je hrvaška verzija dolgega vprašalnika o obcutku koherentnosti (SOC-29) uporabna v raziskavah na podrocju promocije zdravja med hrvaškimi medicinskimi sestrami, zato smo si zadali za cilj oceniti izbrane psihometricne lastnosti instrumenta v tej doloceni poklicni skupini tako z vidika zanesljivosti kot tudi z vidika veljavnosti. Metode: Presecna raziskava, v kateri je sodelovalo 711 medicinskih sester, je bila izvedena v obdobju od decembra 2017 do junija 2018 v Univerzitetnem klinicnem centru Sestre milosrdnice v Zagrebu na Hrvaškem. Na podrocju zanesljivosti se je ocenjevala notranja skladnost. Uporabili smo Cronbachov alfa koeficient (a). Na podrocju veljavnosti se je ocenjevala struktura vprašalnika. Preverjala se je najprej s preiskovalno faktorsko analizo (EFA) (z metodo analize glavnih komponent (PCA) kot metodo ekstrakcije dejavnikov) in nato še s potrditveno faktorsko analizo (CFA). Rezultati: Na podrocju zanesljivosti je analiza pokazala visoko notranjo skladnost instrumenta (a = 0,885). Na podrocju veljavnosti je analiza PCA pokazala pet dejavnikov, s katerimi se je skupaj dalo pojasniti 48,0 % variance, vendar opazovanih dejavnikov ni bilo mogoce razložiti. Tudi ko smo PCA omejili na tri dejavnike, teh ni bilo mogoce razložiti. V CFA noben od modelov ni najbolje ustrezal, ceprav je bila ustreznost trifaktorskega modela (CMIN/DF = 4,786, CFI = 0,767, RMSEA = 0,073) nekoliko boljša v primerjavi z enofaktorskim modelom (CMIN/DF = 6,072, CFI = 0,685, RMSEA = 0,084). Ker se trifaktorskega modela v PCA ni dalo interpretirati, prav tako pa so bili vsi trije dejavniki medsebojno pozitivni in so bistveno korelirani (korelacijski koeficienti: 0,365-0,521), je to kazalo en sam dejavnik v ozadju. Vse postavke so pokazale tudi nasicenost s prvim dejavnikom, s katerim se je dalo pojasniti 25,7 % variance. Zakljucek: Hrvaška razlicica instrumenta SOC-29 je uspešno izpolnila potrebna psihometricna merila za uporabo v populaciji hrvaških medicinskih sester, njenim potencialnim uporabnikom pa je predlagana uporaba enofaktorske strukture, ki jo je zagovarjal tudi avtor instrumenta, prav tako pa so prednost enofaktorski strukturi dali tudi številni drugi avtorji. *Corresponding author: Tel. + 386 31 842 308; E-mail: alenka.franko@siol.net © National Institute of Public Health, Slovenia. 1 INTRODUCTION The Sense of Coherence (SOC) is a key concept of salutogenic model proposed in 1979 by the American-Israeli medical sociologist Aaron Antonovsky (1). It was seen as a coping resource that helped individuals to identify and use their external and internal resources for solving problems and managing life events (1). In order to measure the SOC, Antonovsky developed a special instrument: the Orientation to Life questionnaire, also named the SOC scale. The original version of the instrument consisted of 29 questions (SOC-29), while a shorter version contained 13 questions (SOC-13) (2). Current research by Mittelmark et al. indicates that the SOC-29 and SOC-13 have been used in at least 49 different languages in at least 48 different countries around the world (2). Both instruments were also assessed for their reliability and validity in different population groups, from the general population to various groups of patients (2-9). The results of validation studies proved both instruments to be reliable and cross-culturally appropriate tools (2-4). In these studies, a one-factor structure was often tested against a three-factor structure. Some authors have concluded that the SOC scale is more appropriate as a one-dimensional scale (3, 7), while others have suggested a multidimensional concept (2). Research has proved that nurses constitute a vulnerable population group that faces significantly more stress compared to other professions (10), which may have a negative impact on their health (3-9, 11-14). Research findings on SOC in the nursing profession have so far shown that SOC is a protective factor against stressors in the work environment (15). A strong SOC is also a good predictor of nurses’ ability to function healthily in the workplace, protecting them against burnout (16). Burnout is also a feature of the nursing profession in Croatia (11, 17). According to Mijakoski et al. (17), Croatian nurses reported high levels of depersonalisation and of organisational and emotional work demands. The study highlighted the need for specific organisational interventions to be implemented in hospital settings. An exploration of SOC among Croatian nurses is therefore urgently required. In 2005 the SOC-29 was translated into Croatian (SOC-29­CRO) and psychometrically tested on the sample of 822 individuals from the general population (18). It has not, however, so far been used to assess the Croatian nursing population. Moreover, to our knowledge the literature currently contains only a handful of studies that attempt to validate the SOC-29 among nurses (19, 20). The study aimed to validate the SOC-29-CRO for use as part of health promotion research among Croatian nurses. Its objective study was to assess selected psychometric characteristics of the instrument within this particular occupational group. 2 METHODS 2.1 Study Design and Study Population This cross-sectional study was carried out as part of a larger research project on the impact of SOC on work ablity of nurses at University Hospital Centre Sisters of Mercy (UHCSM) in Zagreb, Croatia between December 2017 and June 2018. The total population of 1,465 nurses of different profiles (registered nurses, Bachelors of nursing, Masters of Science in nursing) employed in different departments of the UHCSM were considered for inclusion in the study regardless of their education level. However, due to various absences (sick leave, annual leave, study leave), questionnaires could only be delivered to 1,300 nurses. 2.2 Description of the SOC-29 Study Instrument SOC-29 is an instrument with 29 items, each of them being scored on a seven-point scale (1) (Table 1). Thirteen items are formulated negatively and have to be reversed in scoring. The measure given by SOC-29 is a summary score, obtained by adding the values of individual responses to all 29 items, ranging from 29-203 points, with higher scores indicating a stronger SOC (2, 3). Written permission to use SOC-29-CRO was obtained from the translators, as well from the copyright holders of the original SOC-29 instrument. 2.3 Instrument Administration After obtaining the approval of the Ethics Committee, a meeting was held at which the participants were informed of the objectives of the research and the overall procedure. After the meeting, all study instruments were distributed in sealed envelopes to all hospital departments. Participants were given the possibility of taking the questionnaire home, filling it in and returning it to the workplace. All questionnaires were returned anonymously in sealed envelopes to protect nurses’ privacy. 2.4 Psychometric Validation In order to assess the instrument’s reliability, internal consistency was assessed by calculating Cronbach’s alpha coefficient (a). The instrument was considered to be internally consistent if a=0.80 (21). In order to assess the instrument’s validity, the factor structure of the instrument was assessed by using exploratory factor analysis (EFA) as well as confirmatory factor analysis (CFA). In EFA, the data screening, assumption testing and sampling adequacy were performed first using the Kaiser-Meyer-Olkin (KMO) statistic with appropriate values >0.5 and Bartlett’s sphericity test with appropriate values p=0.05 (22). The Kolmogorov-Smirnov (K-S) test was also performed for testing the normality of distributions. The principal component analysis (PCA) was then used as the extraction method. In CFA, the robust maximum likelihood Table 1. Sense of Coherence 29-item instrument: items, their placement within three dimensions, and scoring (1). Item no Question* Dimension Scoring Item_1 When you talk to people, do you have the feeling that they don’t understand you? C R Item_2 Think of the people with whom you come into contact daily, aside from the C O ones to whom you feel closest. How well do you know most of them? Item_3 Has it happened in the past that you were surprised by the C R behaviour of people whom you thought you knew well? Item_4 In the past ten years your life has been: (full of changes without your C O knowing what will happen next – completely consistent and clear) Item_5 Do you have the feeling that you are in an unfamiliar situation and don’t know what to do? C O Item_6 When you face a difficult problem, the choice of a solution is: (always CO confusing and hard to find – always completely clear) Item_7 Your life in the future will probably be: (full of changes without knowing C O what will happen next – completely consistent and clear) Item_8 Do you have very mixed-up feelings and ideas? CO Item_9 Does it happen that you have feelings inside you would rather not feel? C O Item_10 Does it happen that you have the feeling that you don’t know exactly what’s about to happen? CO Item_11 When something happened, have you generally found that: (you overestimated C O or underestimated its importance – you saw things in the right proportion) Item_12 In the past, when you had to do something which depended upon cooperation with others, Ma O did you have the feeling that it: (surely wouldn’t get done – surely would get done) Item_13 Has it happened that people whom you counted on disappointed you? Ma R Item_14 Do you have the feeling that you’re being treated unfairly? Ma O Item_15 What best describes how you see life: (one can always find a solution to Ma R painful things in life – there is no solution to painful things in life) Item_16 When something unpleasant happened in the past your tendency was: (“to Ma O eat yourself up about it” – to say “OK that’s that, I have to live) Item_17 When you do something that gives you a good feeling: (it’s certain that you’ll go Ma R on feeling good – it’s certain that something will happen to spoil the feeling) Item_18 Do you think that there will always be people whom you’ll be able to count on in the future? Ma R Item_19 Many people – even those with a strong character – sometimes feel like sad sacks Ma R (losers) in certain situations. How often have you felt this way in the past? Item_20 When you think of the difficulties you are likely to face in important aspects of Ma R your life, do you have the feeling that: (you will always succeed in overcoming the difficulties – you won’t succeed in overcoming the difficulties) Item_21 How often do you have feelings that you’re not sure you can keep under control? Ma O Item_22 Do you have the feeling that you don’t really care about what goes on around you? Me R Item_23 Life is: (full of interest – completely routine) Me R Item_24 Until now your life has had: (no clear goals or purpose at all – very clear goals and purpose) Me O Item_25 Most of the things you do in the future will probably be: Me R (completely fascinating – deadly boring) Item_26 When you think about your life, you very often: (feel how good Me R it is to be alive – ask yourself why you exist at all) Item_27 Doing the things you do every day is: (a source of deep pleasure Me R and satisfaction – a source of pain and boredom) Item_28 You anticipate that your personal life in the future will be: (totally Me O without meaning or purpose – full of meaning and purpose) Item_29 How often do you have the feeling that there’s little Me O meaning in the things you do in your daily life? Legend: *= the questions from the questionnaire are reprinted with the permission of the copyright holder; C=comprehensibility; Ma=manageability; Me=meaningfulness; O=original; R=reverse estimator was applied and the following fit measures used The SOC-29-CRO instrument was completed by 711 in the assessment: the relative chi-square (chi-square/ participants. The mean value of the SOC-29-CRO summary degree of freedom) (CMIN/DF), the comparative fit index score in our study was 145.0±22.1 points. The coefficient (CFI), and the root mean squared error of approximation of relative variation was 15.2%. The statistical properties (RMSEA). The criteria for fit measures were: CMIN/DF<5 of the distribution of the individual item values are shown (23), RMSEA<0.060 (24) and CFI>0.950 (24). Two models in Table 3. were defined and tested: the one- and three-factor model. Statistical analysis was performed using SPSS software, Table 3. Statistical properties of the distribution of values of version 23.0 (SPSS Inc., Chicago, IL, USA), except for the items of the Sense of Coherence 29-item scale in the CFA, where AMOS software was used. validation study of Croatian nurses (n=711). Item x SD Me IQR 3 RESULTS Item_1 4.8 1.6 5 4–6 3.1 Study Participants’ Characteristics Item_2 4.6 1.4 5 4–6 Of the 1,300 nurses eligible for inclusion, 713 participated Item_3 3.8 1.4 4 3–5 in the study (response rate 54.7%). The group consisted Item_4 3.8 1.7 4 3–5 of 630 women and 83 men. The mean age was 38.4±12.5 Item_5 4.8 1.6 5 4–6 years (range: 19-65 years). All other characteristics of the Item_6 4.7 1.4 5 4–6 study participants are presented in Table 2. Item_7 4.3 1.5 4 3–5 Item_8 5.6 1.5 6 5–7 Item_9 5.0 1.7 5 4–6Table 2. Socio-demographic and work-related characteristics Item_10 4.8 1.7 5 4–6 of the study participants (n=713). Item_11 4.6 1.4 6 5–7 Item_13 3.8 1.5 4 3–5 Item_14 4.5 1.8 5 3–6 Item_15 5.6 1.5 6 5–7 Age 19–30 247 34.6 Item_16 5.0 1.7 5 4–7 31-40 161 22.6 Item_17 4.9 1.7 5 4–6 41–50 159 22.3 Item_18 5.8 1.5 6 5–7 51–65 145 20.4 Item_19 4.4 1.4 5 3–6Marital status Married 371 52.0 Item_20 5.1 1.4 5 4–6 Divorced 48 6.7 Item_21 5.0 1.7 5 4–6 Widowed 18 2.5 Item_22 4.6 1.4 5 4–6 Single 186 26.1 Item_23 3.8 1.4 4 3–5 Life partnership 89 12.5 Item_24 3.8 1.7 4 3–5 Level of High school education 429 60.2 education Item_25 4.8 1.6 5 4–6 Bachelor of nursing 256 35.9 Item_26 4.7 1.4 5 4–6 Master of nursing 28 3.9 Item_27 4.3 1.5 4 3–5 Work Internal unit 179 25.3 department Item_28 5.6 1.5 6 5–7 Surgery unit 157 22.2 Item_29 5.0 1.7 5 4–6 Operating room 33 4.7 Intensive care unit 73 10.3 Legend: x=mean; s=standard deviation; Me=median; Gynaecology unit 52 7.3 IQR=interquartile range Polyclinical unit 23 3.2 Oncology and 58 8.2 haematology unit Dermatology unit 13 1.8 Emergency unit 27 3.8 Ophthalmology unit 28 4.0 Psychiatry unit 34 4.8 Paediatrics unit 31 4.4 Length of Less than 1 year 23 3.2 service 1–19 years 391 54.8 20 or more years 299 41.9 3.2 Psychometric Validation 3.2.1 Reliability Cronbach’s alpha coefficient was high (a=0.885), indicating high internal consistency of the instrument. 3.2.2 Factor Structure Both the KMO statistic (KMO=0.913) and Bartlett’s sphericity test (p<0.001) indicated adequate properties for the PCA. The K-S test did not show statistically significant deviations from the normal distribution (p=0.063). PCA analysis has identified five factors which together accounted for 48% of the variance (Table 4). However, the observed factors could not be interpreted. A PCA limited to three factors also showed an uninterpretable structure. The statistical properties of both models defined and tested using CFA are presented in Table 5. None of the models fitted well (Table 5). Moreover, all three factors in the three-factor model were mutually positive and significantly correlated (r=0.365-0.521). Table 4. Results of exploratory factor analysis (extraction method: principal component analysis) in the validation study of the Sense of Coherence 29-item scale among Croatian nurses (n=711). Component Initial Eigenvalues Extraction sums of squared loadings Total % of variance Cumulative % Total % of variance Cumulative % 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 7.453 2.396 1.693 1.236 1.143 0.982 0.955 0.935 0.897 0.841 0.811 0.767 0.725 0.700 0.681 0.643 0.623 0.593 0.565 0.547 0.534 0.515 0.471 0.448 0.417 0.389 0.366 0.345 0.328 25.700 8.262 5.839 4.262 3.943 3.388 3.294 3.223 3.092 2.900 2.797 2.646 2.500 2.415 2.349 2.217 2.147 2.046 1.947 1.886 1.842 1.776 1.623 1.546 1.439 1.340 1.261 1.189 1.131 25.700 33.962 39.801 44.063 48.005 51.393 54.687 57.910 61.003 63.903 66.699 69.345 71.846 74.261 76.610 78.827 80.975 83.021 84.968 86.854 88.695 90.471 92.095 93.640 95.079 96.419 97.680 98.869 100.000 7.453 25.700 25.700 2.396 8.262 33.962 1.693 5.839 39.801 1.236 4.262 44.063 1.143 3.943 48.005 Table 5. Results of confirmatory factor analysis in validation Additionally, in PCA all the items have shown first factor, study of the Sense of Coherence 29-item scale among which accounted for 25.7% of the variance (Table 4), Croatian nurses (n=711). loading. The factor loadings, which were considered satisfactory, are shown in Table 6. Chi-square 2289.11 1790.13 4 DISCUSSION Degrees of freedom 377 374 p <0.001 <0.001 The results of our study show that the SOC-29-CRO CMIN/DF 6.072 4.786 successfully fulfilled the required psychometric criteria CFI 0.685 0.767 for being used within the Croatian nursing population. RMSEA 0.084 0.073 The results of the reliability analysis in our study are Legend: CMIN/DF=relative chi-square (chi-square/degree of freedom); CFI=comparative fit index; RMSEA=root mean squared consistent with the results reported in other similar error of approximation studies. First, the reliability obtained in our study is in the upper range of values for this measure obtained in other similar studies in general (range 0.70-0.95) (2-5). Table 6. Factor loadings greater than 0.200 in the validation study of the Sense of Coherence 29-item scale among Croatian nurses (n=711). Component Component loads 1st 2t 3t 4st 5st Item_1 0.443 0.363 Item_2 0.342 0.320-0.325 Item_3 0.352 0.521 0.262 0.257 Item_4 0.277 0.626-0.340 Item_5 0.483 0.277-0.416 Item_6 0.468 0.392-0.394 Item_7 0.305 0.600 -0.290 Item_8 0.547 0.241-0.301-0.236 -0.216 Item_9 0.565 0.404-0.306 Item_10 0.399 0.246-0.292 Item_11 0.515 0.383 Item_12 0.542 0.203 0.315 Item_13 0.403 0.527 0.266 Item_14 0.512 0.383 -0.362 Item_15 0.520 -0.317 Item_16 0.497 -0.225 Item_17 0.496 0.217 Item_18 0.581 -0.204 0.210 Item_19 0.500 0.317 Item_20 0.589 -0.211-0.203 Item_21 0.430 0.337 0.219 Item_22 0.355 0.240 -0.210 0.340 Item_23 0.551 -0.352 -0.260 Item_24 0.626 -0.310 Item_25 0.677 -0.355 -0.207 Item_26 0.718 -0.243 Item_27 0.625 -0.266 0.244 Item_28 0.667 -0.404-0.223 Item_29 0.345 0.310 0.209 Finally, the results of our study are similar to the results of the study conducted among Portuguese nurses with a reported Cronbach’s alpha value of 0.87 (19). The reliability obtained in our study is also completely consistent with the reliability obtained in the study by Kardum et al. (18). The value of Cronbach’s alpha coefficient in this study was almost identical (a=0.88). The analysis of factor structure in our study first identified five factors (a similar result was obtained in the studies conducted by Frenz et al. (7) and Paika et al. (5). In both studies in continuation one-factor structure was revealed. In the study by Frenz et al., subsequent analysis of the factor scores suggested the scale had one core factor. The authors stated that the results suggested that the SOC was best understood as having a single core factor (7). Paika et al. repeated the factor analysis using the fixed number of factors as the extracted model, which resulted in one factor being extracted. Their study revealed that an SOC­ 29 one-factor structure showed a coherent structure with remarkable stability (5). The study conducted among Portuguese nurses also confirmed the one-factor structure (19). As in our study all the items showed saturation with the first factor, we decided to use the one-factor structure advocated by other authors (5, 7). This was despite the fact that the percentage of the explained variance could not be considered satisfactory. However, we can justify this by the fact that we investigated a specific sample, i.e. a population of nurses employed in a precisely designated hospital. The coefficient of relative variation for SOC can also be considered low. Unlike our study, the study by Kardum et al. (18) showed a three-factor structure. However, in their conclusions they drew on the use of the overall result rather than the three components. This was because they discussed the inadequacy of their functional differentiation. In order to make a comparison with this study, we also tested a three-factor model. However, the three-factor structure deviated significantly from the structure advanced by other authors and, in our case, also proved uninterpretable, despite the rotations. For this reason, we decided to adopt the one-factor structure. These leads us to conclude that authors generally prefer the one-factor structure of the instrument. The one-factor model was also advocated by Antonovsky himself, since the instrument was not intended to measure dimensions individually (1). Since the SOC-29-CRO has been already validated among the Croatian general population (18), it is important to explain why the authors considered it necessary to validate the instrument again on a specific nursing population. The first reason has been already presented: in the first SOC-29-CRO validation study, the factor structure of the instrument was not clear, even though the authors had proposed that a one-factor structure be used. This ambiguity could be the result of the internal heterogeneity of the sample of the general population. Consequently, we decided that it was important to re­examine the factor structure on a specific population (like the nursing population addressed in this study) for the purposes of further research. The nursing population predominantly consists of women who are of reproductive age, have a higher level of education and are also exposed to extremely high levels of workplace stress (12). A study on the perception of stress conducted in Slovenia, a country similar to Croatia, found that employed women with at least college-level education were at very high risk of suffering from frequent stress perception (25). Various studies show that differences exist between the genders as regards experience of stress, with women estimating stressors as more severe than men and tending to report higher rates of psychological distress (26). The reason for this may lie in the fact that employed women have to cope with various roles in their professional and private lives and that their experience of the environments in which they live and work is probably different from that of men. It is therefore reasonable to conclude that this group deviates very significantly from the general population, which could also be reflected in the results of the instrument validation. Our study has some potential limitations. First, one can argue that this study only includes nurses from one hospital in Croatia. A counter-argument would be that this hospital is a typical large healthcare institution that employs a large number of nurses of different profiles. This allows in-depth research into health problems related to the nurses’ workplace. Second, the response rate/number of participants was towards the lower recommended limit, but nevertheless still within the values that allow robust correct conclusions to be drawn. Third, one could argue this study used no method of measurement of stability of the instrument over time, e.g. the test-retest method. We counter this by the fact that the reliability of any self-reported outcome measure can be evaluated using measurement stability methods and/or measurement equivalence methods. The latter were developed from social science research for situations in which it was not possible to perform repeated measurements because the measured phenomenon had changed or could change over time (27). Finally, one can argue that this study tested only one- and three-factor models. Our argument here is that, in accordance with the existing theoretical assumptions (2), the results of other studies (2-5, 7, 8) that have the confirmed one- and three-factor structure of the SOC questionnaire, and with the results of PCA in our study, it was rational to test only the one- and the three-factor models. The study also has several important strengths, the most prominent being that it provided additional and important information and knowledge about the psychometric properties of the SOC-29-CRO when evaluated in a Croatian nursing population. The study showed the one-factor structure more directly than the study on the general population. As a result, the one-factor structure of the SOC-29-CRO can be more reliably used in subsequent research on nurses. Finally, the fact that the study was conducted among the nurses of a single hospital only can be an advantage as well as a limitation, since this institution is similar to many other institutions in countries that are experiencing similar transition processes to Croatia. The results of this study could apply to these hospitals as well, especially those in the countries of former Yugoslavia. The study results are significant for occupational medicine, health organisations and nursing management in Croatia and beyond. Nurses are often exposed to occupational hazards in their work environment which can lead to stress (11). The outcome of these stressful events depends on how nurses cope with stress. Weak SOC prevents nurses from actively managing stressful events, which can lead to work-related health problems. The SOC-29-CRO instrument could be used by nursing managers to identify nurses with weak SOC and implement interventions to create healthy working environments and protect and promote nurses’ health. Actively managing nurses’ health can help to increase their work ability. This instrument could also be helpful when planning the introduction of coping strategies among nursing students as well as among students of other healthcare professions, since it has already been proven that high levels of perceived stress predispose health students to anxiety and a lower quality of life (28). A number of challenges remain for those studying the use of SOC-29-CRO in nursing populations. The dynamics/stability of the SOC-29-CRO must first be checked over a longer period of time in time, especially in relation to those nurses with more demanding jobs (e.g. in intensive care departments). With a focus on studying the properties of the SOC-29-CRO in the nursing population, our work could usefully be continued by analysing additional aspects of validity, e.g. criterion validity. 5 CONCLUSIONS The adequate psychometric properties of the instrument indicate that SOC-29-CRO is a reliable tool for use in further research. In the near future, it may also be important to the process of designing measures for enhancing nurses’ internal resources for the management of workloads. ACKNOWLEDGEMENTS The authors are grateful to all the nurses who took part in the survey. Zdr Varst. 2020;59(3):155-163 CONFLICTS OF INTEREST The authors declare no conflicts of interest. FUNDING The study received no funding. ETHICAL APPROVAL The study was approved by tthe University Hospital Centre Sisters of Mercy (reference no EP-7811/16-19). The research was carried out in accordance with the ethical principles of the Helsinki Declaration. All respondents gave their informed consent to participate in the study. REFERENCES 1. Antonovsky A. Unraveling the mystery of health: How people manage stress and stay well. San Francisco, CA: Jossey-Bass, 1987. 2. Mittelmark MB, Sagy S, Eriksson M, Bauer GF, Pelikan JM, Lindström B, et al, editors. The handbook of salutogenesis. Cham, CH: Springer, 2017. 3. Antonovsky A. The structure and properties of the sense of coherence scale. Soc Sci Med. 1993;36:725-33. doi: 10.1016/0277-9536(93)90033­ z. 4. Eriksson M, Lindström B. Validity of Antonovsky’s sense of coherence scale: a systematic review. J Epidemiol Community Health. 2005;59:460-6. doi: 10.1136/jech.2003.018085. 5. Paika V, Ntountoulaki E, Papaioannou D, Hyphantis T. The Greek version of the Sense of Coherence Scale (SOC-29): psychometric properties and associations with mental illness, suicidal risk and quality of life. J Psychol Clin Psychiatry. 2017;7:10. doi: 10.15406/ jpcpy.2017.07.00449. 6. Bonacchi A, Miccinesi G, Galli S, Chiesi F, Martire M, Guazzini M, et al. The dimensionality of Antonovsky’s Sense of Coherence Scales: an investigation with Italian samples. TPM Test Psychom Methodol Appl Psychol. 2012;19:115-34. doi: 10.4473/TPM19.2.4. 7. Frenz AW, Carey MP, Jorgensen RS. Psychometric evaluation of Antonovsky’s sense of coherence scale. Psychol Assess. 1993;5:145-53. doi: 10.1037/1040-3590.5.2.145. 8. Spadoti Dantas RA, Silva FS, Ciol MA. Psychometric properties of the Brazilian Portuguese versions of the 29- and 13-item scales of the Antonovsky’s sense of coherence (SOC-29 and SOC-13) evaluated in Brazilian cardiac patients. J Clin Nurs. 2014;23:156-65. doi: 10.1111/ jocn.12157. 9. Stern B, Socan G, Rener-Sitar K, Kukec A, Zaletel-Kragelj L. Validation of the Slovenian version of short sense of coherence questionnaire (SOC-13) in multiple sclerosis patients. Zdr Varst. 2019;58:31-9. doi: 10.2478/sjph-2019-0004. 10. Geuens N, Braspenning M, Van Bogaert P, Franck E. Individual vulnerability to burnout in nurses: the role of Type D personality within different nursing specialty areas. Burnout Res. 2015;2:80-86. doi: 10.1016/j.burn.2015.05.003. 11. Hudek-Knezevic J, Kalebic Maglica B, Krapic N. Personality, organizational stress, and attitudes toward work as prospective predictors of professional burnout in hospital nurses. Croat Med J. 2011;52:538-49. doi: 10.3325/cmj.2011.52.538. 12. Dobnik M, Maletic M, Skela-Savic B. Work-related stress factors in nurses at Slovenian hospitals -a cross-sectional study. Zdr Varst. 2018;57:192-200. doi: 10.2478/sjph-2018-0024. 13. Starc J. Stress factors among nurses at the primary and secondary level of public sector health care: the case of Slovenia. Open Access Maced J Med Sci. 2018;6:416-22. doi: 10.3889/oamjms.2018.100. 14. Labrague LJ, McEnroe-Petitte DM, Leocadio MC, Van Bogaert P, Cummings GG. Stress and ways of coping among nurse managers: an integrative review. J Clin Nurs. 2018;27:1346-59. doi: 10.1111/ jocn.14165. 15. Malagón-Aguilera MC, Fuentes-Pumarola C, Suńer-Soler R, Bonmatí-Tomŕs A, Fernández-Peńa R, Bosch-Farré C. The sense of coherence among nurses. Enferm Clin. 2012;22:214-8. doi: 10.1016/j. enfcli.2012.06.002. 16. Basinska MA, Andruszkiewicz A, Grabowska M. Nurses’ sense of coherence and their work related patterns of behaviour. Int J Occup Med Environ Health. 2011;24:256-66. doi:10.2478/S13382-011-0031-1. 17. Mijakoski D, Karadzinska-Bislimovska J, Milosevic M, Mustajbegovic J, Stoleski S, Minov J. Differences in burnout, work demands and team work between Croatian and Macedonian hospital nurses. Cogn Brain Behav. 2015;19:179-200. 18. Kardum I, Hudek-Kneževic J, Kola A. The relationship between the sense of coherence, the dimension of the five-factor personality model and the subjective health outcomes. Psihol Teme. 2005;14:79-94. 19. Schmidt DR, Dantas RA. Analysis of validity and reliability of the adapted portuguese version of Antonovsky’s sense of coherence questionnaire among nursing professionals. Rev Lat Am Enfermagem. 2011;19:42-9. doi: 10.1590/S0104-11692011000100007. 20. Langius A, Björvell H. Salutogenic model and utilization of the KASAM form (Sense of Coherence) in nursing research -a methodological report. Vard Nord Utveckl Forsk. 1996;16:28-32. doi: 10.1177/010740839601600106. 21. Howitt D, Cramer D. Introduction to statistics in psychology. 3rd ed. Essex: Pearson Education Limited, 2005. 22. Schmitt TA. Current methodological considerations in exploratory and confirmatory factor analysis. J Psychoeduc Assess. 2011;29:304-21. doi: 10.1177/0734282911406653. 23. Marsh HW, Hocevar D. Application of confirmatory factor analysis to the study of self-concept: first-and higher order factor models and their invariance across groups. Psychol Bull.1985;97:562-82. doi: 10.1037/0033-2909.97.3.562. 24. Hu L, Bentler PM. Cutoff criteria for fit indexes in covariance structure analysis: conventional criteria versus new alternatives. Struct Equ Modeling. 1999;6:1-55. doi: 10.1080/10705519909540118. 25. Zaletel-Kragelj L, Pahor M, Bilban M. Identification of population groups at very high risk for frequent perception of stress in Slovenia. Croat Med J. 2005;46:137-45. 26. Rivera-Torres P, Araque-Padilla RA, Montero-Simo MJ. Job stress across gender: the importance of emotional and intellectual demands and social support in women. Int J Environ Res Public Health. 2013;10:375­ 89. doi: 10.3390/ijerph10010375. 27. Ferligoj A, Leskošek K, Kogovšek T. Methodological notes 10: reliability and validity of measurement. Ljubljana: University of Ljubljana, FDV, 1995. 28. Racic M, Todorovic R, Ivkovic N, Masic S, Joksimovic B, Kulic M. Self- Perceived stress in relation to anxiety, depression and health-related quality of life among health professions students: a cross-sectional study from Bosnia and Herzegovina. Zdr Varst. 2017;56:251-9. doi: 10.1515/sjph-2017-0034. Robic Pikel T, Malus T, Starc G, Golja P. Changes in the growth and development of adolescents in a country in socio-economic transition 1993–2013. Zdr Varst. 2020;59(3):164-171. doi: 10.2478/sjph-2020-0021. CHANGES IN THE GROWTH AND DEVELOPMENT OF ADOLESCENTS IN A COUNTRY IN SOCIO-ECONOMIC TRANSITION 1993–2013 SPREMEMBE V RASTI IN RAZVOJU MLADOSTNIKOV V DRŽAVI S SOCIO-EKONOMSKIM PREHODOM V OBDOBJU 1993–2013 Tatjana ROBIC PIKEL1*, Tina MALUS1, Gregor STARC2, Petra GOLJA1 1University of Ljubljana, Biotechnical Faculty, Department of Biology, Vecna pot 111, 1000 Ljubljana, Slovenia 2University of Ljubljana, Faculty of Sport, Gortanova ulica 22, 1000 Ljubljana, Slovenia Received: Nov 19, 2019 Accepted: Jun 2, 2020 ABSTRACT Keywords: secular trends, growth spurt, body height, body proportions, leg length, leg-to­ body height ratio, leg-to-trunk ratio IZVLECEK Kljucne besede: sekularni trendi, rastni sunek, telesna višina, telesna razmerja, dolžina nog, razmerje nog in telesne višine, razmerje nog in trupa Original scientific article Introduction: Changes in human growth and development depend on genetic and environmental factors. In the case of Slovenia, the environmental factors changed as a result of the period of socio-economic transition that the country underwent between 1991 and 2013. The authors used anthropometric techniques to evaluate differences in body height, proportions and sexual maturity in 1,221 adolescents aged 14 in 1993, 2003 and 2013. Methods: Data was collected as a part of the ACDSi study, which has monitored children’s somatic growth and motor development every decade over the last 40 years. Results: Between 1993 and 2013, a trend (p=0.08) towards increased body height was observed in males. The comparison of age at peak height velocity (PHV) between generations demonstrated a trend (p=0.07) of earlier entry into puberty in adolescents in 2013 compared to those in 1993. The leg-to-body height ratio increased (p<0.05) with every decade in males, while in females it decreased (p<0.05) in 2013. Similar trends were observed in the leg-to-trunk ratio. Contemporary generations experienced PHV at a younger age (p<0.05), which is true for both genders even in adolescents born no more than two decades (1993, 2013) apart. In both generations, females experienced PHV sooner than their male peers. Conclusion: The authors assume that females of the 2013 generation reached puberty earlier than females of older generations. It is most likely that, unlike females from older generations and unlike males, they were already at the stage of trunk growth at the time of the measurements, which explains the observed changes in their trunk length, leg-to-body height and leg-to-trunk ratios in comparison to earlier generations. Uvod: Spremembe rasti in razvoja cloveka so odvisne od genetskih in okolijskih dejavnikov. Slednji so se zaradi obsežnega socialno-ekonomskega prehodnega obdobja v Sloveniji med letoma 1991 in 2013 mocno spremenili. Avtorji so z antropometrijo želeli oceniti možne razlike v telesni višini, telesnih razmerjih in spolnem dozorevanju pri 1.221 mladostnikih, ki so bili v letih 1993, 2003 ali 2013 stari 14 let. Metode: Podatki so bili zbrani kot del študije ARTOS (Analiza razvojnih trendov otrok v Sloveniji), ki v zadnjih štirih desetletjih vsakih 10 let spremlja somatsko rast in motoricni razvoj otrok. Rezultati: Med leti 1993 in 2013 so pri moških mladostnikih opazili trend (p = 0,08) povecanja telesne višine. Primerjava starosti pri najvišji hitrosti višine (PHV) med generacijami je pokazala trend (p = 0,07) zgodnejšega vstopa v puberteto pri mladostnikih iz leta 2013 v primerjavi s tistimi iz leta 1993. Noge so bile pri moških v letu 2013 v povprecju daljše (p < 0,01) kot v letih 1993 in 2003, medtem ko se dolžina nog pri ženskah v dveh desetletjih ni spremenila. Po drugi strani pa je bil trup pri ženskah v letu 2013 daljši (p < 0,05) kot leta 1993, pri moških pa je bilo nasprotno (p < 0,05). Razmerje med dolžino nog in telesno višino se je pri moških z vsakim desetletjem povecalo (p < 0,05), medtem ko se je to razmerje pri ženskami v letu 2013 zmanjšalo (p < 0,05). Podobno so opazili pri razmerju med dolžino nog in dolžino trupa (p < 0,05). Mlajše generacije so PHV doživele pri nižji starosti (p < 0,05), kar velja za oba spola mladostnikov, rojenih ne vec kot dve desetletji narazen (1993, 2013). V obeh generacijah so ženske PHV doživele prej (p < 0,05) kot moški vrstniki. Zakljucek: Na podlagi rezultatov domnevajo, da so ženske iz generacije 2013 puberteto dosegle prej kot ženske iz starejše generacije; najverjetneje so bile, v nasprotju z ženskami iz starejših generacij in moških v casu meritev, že v fazi rasti trupa, kar pojasnjuje opažene spremembe v dolžini trupa, obeh razmerjih nog glede na telesno višino ali glede na dolžino trupa v primerjavi s prejšnjimi generacijami. *Corresponding author: Tel. + 386 1 320 34 21; E-mail: tatjana.robic@bf.uni-lj.si © National Institute of Public Health, Slovenia. 1 INTRODUCTION The growth and development of the human body from birth and through childhood and adolescence are reflected in body size and the proportions of body parts in adulthood (1). Different secular trends in human growth and development, e.g. changes in childhood growth patterns and earlier sexual maturation, have been observed in many countries over the last century (2). Important factors underlying the secular growth changes are environmental factors such as industrialisation (2) and an increase in general economic status (3). By monitoring changes of growth in children and adolescents of the same age from different generations who had been affected by such factors, it should be possible to determine the impact of these changes on the pattern, velocity and duration of an individual’s growth. During childhood, different regions of the body experience different growth patterns (4). Distal parts of the limbs approach adult size sooner than their proximal parts (5): thus, in the lower extremities, the feet fully develop earlier than the tibia and the tibia grows faster (to an almost adult size) than the femur. The same pattern of growth is also observed in the upper extremities (6). Childhood ends with puberty and adolescence. Puberty is the process of physical changes by which adolescents reach sexual maturity, i.e. become capable of reproduction, while adolescence can be described as a dynamic period characterised by rapid changes in body height, shape, and body structure, and by morphological gender differences (7). One of the characteristics of adolescence is the growth spurt, which is a period of accelerated leg growth that can be observed prior to accelerated trunk growth. In an interval during early adolescence, an individual will therefore have relatively long legs; this appearance will, however, disappear with the consequent increase in trunk length (8). Since females enter adolescence on average two years earlier than males, they have, on average, longer legs for a shorter period than males during early adolescence (9). During their growth spurt, adolescents experience their peak height velocity (PHV), which is the fastest growth in body height (10). In females, PHV occurs between the ages of ten and 14 on average, which is approximately two years sooner than in males (11); this corresponds to the period of earlier entrance into adolescence in females compared to males (9). The age at PHV is the most commonly used indicator of biological maturity in longitudinal studies of puberty (1, 12), as data on age and corresponding body height is relatively easy and inexpensive to collect. By referring to PHV, we can accurately determine maximum growth during puberty and compare it between individuals (13). It has been reported that contemporary adolescents experience PHV (10) and final body height at a lower chronological age (2) than their peers in previous generations. The aim of the present study is to assess whether the change in environmental factors over a 20-year period (when Slovenia experienced significant socio-economic transition) was influential enough to be reflected in altered growth and the age at which adolescents achieved sexual maturity. The twin objectives of the study were therefore to determine whether the ratio between leg and trunk length changed among 14-year-old adolescents between 1993 and 2013, and whether adolescents experienced PHV earlier in 2013 than did adolescents of the same age two decades earlier. An earlier beginning of sexual maturity could be reflected in an earlier start to trunk growth (and consequently a smaller leg-to-body height ratio and leg-to-trunk ratio in adolescents of the same age from different generations). We hypothesised that this should be primarily evident in females, as they enter puberty earlier than males. 2 METHODS 2.1 Observed Population To achieve the aims of this study, basic anthropometric data was obtained from three samples of 14-year-old subjects in Slovenia: from a sample measured in 1993, from a second sample measured in 2003 and from a third sample measured in 2013. 2.2 Sampling Procedure The present study is a part of the longitudinal ACDSi project (Analysis of Children’s Development in Slovenia), led by the Faculty of Sport of the University of Ljubljana, Slovenia and conducted in cooperation with other faculties. The project has been under way since 1970 (14). Measurements at primary schools take place every ten years in the same 11 locations all over Slovenia. The locations are selected to reflect four types of settlement (rural, rural-industrial, industrial-rural and industrial) and spread across the regions in order to be representative of the population as a whole (14). The project examines selected physical and developmental characteristics of children between the ages of 6 and 15. The measurements are pre-arranged with the administrators of the participating primary schools, with parental consent for participation being obtained in advance. In order to fulfil our research goals, we planned to include 200 children in each age- and sex-group, with an estimated drop-out rate of 15% (14). 2.3 Study Instruments and Measurements Body height and leg length were measured. Body height was measured using a portable anthropometer (GPM, Switzerland). During this measurement, the subjects were barefoot, their back was straight, their hands were relaxed alongside the body, their feet and knees were together, their heels touched the anthropometer, and their head was held in the Frankfurt horizontal (15). Leg length was measured as the iliospinal height (i.e. the vertical distance between the iliac spine and the floor) (16). A shortened portable anthropometer (GPM, Switzerland) was used for this purpose. During the measurements, the subjects stood with their knees and feet together, and the examiner positioned the top of the anthropometer at the anterior superior iliac spine of the pelvis. Trunk length was calculated by subtracting leg length from body height. The leg-to-body height ratio (i.e. leg length as a proportion of the height of the whole body) was calculated by dividing leg length by body height. The leg-to-trunk ratio was calculated by dividing leg length by trunk length. In addition, body height data for adolescents who were 14 years old in either 1993 or 2013 was obtained over four consecutive years from ages 10 to 14 from the national surveillance system of somatic and motor development (SLOfit). The SLOfit measurements take place every year in April and cover children and adolescents from all Slovenian primary and secondary schools from ages 6 to 18. Annual increments in body height (cm/year) were calculated for each individual as the differences in their body height between two consecutive years. The largest Zdr Varst. 2020;59(3):164-171 annual increment in body height was adopted as the PHV, while the lower margin of an annual interval in which the PHV was observed was adopted as the age at PHV. 2.4 Methods of Analysis Descriptive statistics (means and standard deviation (SD)) were obtained for subjects’ age, body height, leg and trunk length, as well as for both ratios. The values of the three generations were compared with a one-way analysis of variance (ANOVA) and Tukey’s HSD post-hoc test. A student’s t-test was used to compare PHV and age at PHV between the generations of 1993 and 2013. The level of statistical significance was set at p<0.05. 3 RESULTS 3.1 Description of the Study Group Anthropometric data was obtained from a total of 1,221 adolescents (674 males and 551 females) measured in 1993, 2003 and 2013. Response rate was approximately 82%, which represents around 2% of the entire population of children in primary schools in Slovenia (14). Their mean age, body height, leg and trunk length, leg-to­body height ratio, and leg-to-trunk ratio, as well as the corresponding p-values for the comparisons between the three generations are presented in Table 1. Table 1. Typical values of body measurements (mean and standard deviation (SD)) in 14-year-old males and females in Slovenia in 1993, 2003 and 2013. ANOVA – one-way analysis of variance, HSD – honestly significant difference. Year of measurement Tukey’s HSD test (p) 1993 2003 2013 One-way ANOVA (p) 1993 vs. 2003 2003 vs. 2013 1993 vs. 2013 Males Subject number [N] 222 236 216 Age [years] 14.1 (0.4) 14.0 (0.3) 14.2 (0.3) <0.001 <0.001 <0.001 0.004 Body height [cm] 167.6 (8.7) 165.1 (8.3) 169.0 (7.7) <0.001 0.001 <0.001 0.089 Leg length [cm] 96.4 (6.1) 95.7 (5.8) 98.9 (5.5) <0.001 0.234 <0.001 <0.001 Trunk length [cm] 71.3 (4.5) 69.4 (4.5) 70.1 (5.2) <0.001 <0.001 0.103 0.012 Leg-to-body height ratio [%] 57.5 (1.8) 58.0 (1.8) 58.5 (2.2) 0.017 0.003 0.004 <0.001 Leg-to-trunk ratio 1.36 (0.10) 1.38 (0.09) 1.42 (0.16) <0.001 0.002 0.004 <0.001 Females Subject number [N] 179 209 163 Age [years] 14.0 (0.5) 14.0 (0.3) 14.2 (0.3) <0.001 0.788 <0.001 0.002 Body height [cm] 162.6 (6.8) 161.2 (5.9) 163.2 (5.9) 0.004 0.028 0.001 0.345 Leg length [cm] 92.8 (4.8) 92.1 (4.5) 92.5 (4.6) 0.314 0.129 0.457 0.473 Trunk length [cm] 69.8 (3.7) 69.1 (3.8) 70.8 (3.5) <0.001 0.067 <0.001 0.009 Leg-to-body height ratio [%] 57.1 (1.6) 57.1 (1.9) 56.6 (1.7) 0.011 0.719 0.006 0.009 Leg-to-trunk ratio 1.33 (0.09) 1.34 (0.12) 1.31 (0.09) 0.016 0.616 0.010 0.011 3.2 Body Height No significant differences in body height were detected in 14-year-old females between 1993 and 2013, although there was a trend (p=0.089) towards increasing body height in 14-year-old males. However, in comparison to the previous generation, males from the contemporary generation were taller at the age of 10 to 12 years. There was a noticeable difference in the body height of males and females between 1993 and 2003, and between the years 2003 and 2013. In both 1993 and 2013, males were on average 2.5 and 3.9 cm taller respectively, than their peers in 2003. Females in 2013 were on average 2 cm taller than their peers in 2003. 3.3 Leg and Trunk Length In males, a significant difference in leg length and trunk length was observed between 1993 and 2013. Between 1993 and 2013, the leg length of males increased by an average of 2.5 cm, while their trunk length decreased by an average of 1.2 cm. In females, while leg length did not change significantly in the same 20-year period, trunk length did increase by an average of 1 cm between 1993 and 2013. 3.4 Leg-to-Body Height Ratio and Leg-to-Trunk Ratio A comparison of leg-to-body height ratio and leg-to­trunk ratio between the generations of males from 1993, 2003 and 2013 demonstrates that relative leg length (i.e. in comparison with the rest of the body) increased significantly with each decade. The leg-to-body height ratio increased by 0.5 percentage points, i.e. from 57.5% to 58.5% in the period observed. In females, leg-to-body height ratio remained unchanged between 1993 and 2003 (57.1%), falling significantly to 56.6% in 2013. The leg-to­trunk ratio increased by approximately 0.03, i.e. from 1.36 to 1.42 in the period observed. In females, the leg­to-trunk ratio remained unchanged between 1993 and 2003 (at approx. 1.33) and fell significantly to 1.31 in 2013. This means that leg length accounted for a lower percentage of total body height and trunk with head for a larger percentage of total body height in females in 2013 in comparison to females from previous generations. 3.5 Peak Height Velocity (PHV) For the calculation of PHV and age at PHV, data was successfully obtained from 236 14-year-old adolescents from 1993 and 311 14-year-old adolescents from 2013. The mean (SD) age at PHV determined for males of the 1993 and 2013 generations was 12.9 (1.0) and 12.7 (1.0) years respectively. The observed difference was close to the level of statistical significance (p=0.077). Females of the 1993 and 2013 generations were, on average, 11.4 (1.1) and 11.2 (1.0) years old at PHV, i.e. a trend similar to that in males was observed (p=0.071). Table 2 presents the number of adolescents of the 1993 and 2013 generations, who reached PHV at a particular age, values of their mean PHV for a particular age, as well as the corresponding p-values for the comparisons between the two generations. Table 2. Mean (standard deviation (SD)) peak height velocity (PHV) of males and females in the 1993 and 2013 generations. Height increments for the calculation of PHV were obtained for each subject of the two generations from the annual anthropometric measurements performed nationally at schools. Any presented age is the lower margin of an annual interval in which the PHV was observed. The t-test relates to a difference in PHV between 1993 and 2013. NA – not applicable. Males Age at PHV [years] 10 4 {3} 2 {1} 6.8 (2.3) 10.2 (5.4) NA 11 5 {5} 33 {16} 11.0 (0.4) 8.6 (1.9) 0.003 12 34 {29} 33 {16} 10.1 (2.2) 9.2 (1.8) 0.037 13 40 {33} 97 {46} 9.4 (2.0) 9.9 (1.5) 0.048 14 36 {30} 44 {21} 9.5 (1.5) 9.2 (2.1) 0.237 Total 119 {100} 209 {100} 9.6 (2.0) 9.4 (1.9) 0.203 Females Age at PHV [years] 10 30 {26} 32 {31} 8.4 (1.8) 8.0 (1.7) 0.220 11 32 {27} 34 {33} 8.5 (1.7) 7.8 (1.2) 0.042 12 44 {38} 25 {25} 8.4 (1.4) 8.1 (2.2) 0.282 13 6 {5} 10 {10} 8.1 (1.9) 8.2 (2.5) 0.413 14 5 {4} 1 {1} 7.2 (0.8) 7.0 (NA) NA Total 117 {100} 102 {100} 8.3 (1.6) 8.0 (1.7) 0.066 4 DISCUSSION 4.1 The Most Important Results of the Study The results of the present study demonstrate that contemporary generations experience PHV at a younger age. This is true for both genders, even in adolescents born no more than two decades (1993, 2013) apart. As expected, females in both generations experienced PHV sooner than their male peers. The comparison between the 1993, 2003 and 2013 generations demonstrates that males have longer legs and females longer trunks in the latest generation compared to the two previous generations. At the same time, it appears that contemporary females and males experience somewhat different pubertal growth patterns in terms of intensity. While both experience earlier PHV, females experience a growth intensity that is similar to that of previous generations (of females), resulting in earlier conclusion of pubertal growth, while males experience earlier PHV than in previous generations, but also lower intensity. This results in their slower (although longer) pubertal growth. Related to the above, leg-to-body height ratio and leg-to­trunk ratio increased significantly in males and decreased significantly in females over the time period observed. 4.2 Comparison of the Results to the Results of Similar Studies It has been reported that adolescence in females starts at least two years earlier than in males: females enter adolescence at the age of around 11 years on average and males at the age of 13 years on average (17, 18). Females also reach PHV earlier than males, as was confirmed in the study by Malina et al. (8) performed in North America and Europe between 1988 and 1998. In this study, females reached PHV between the ages of 11.3 (11 years and 4 months) and 12.2 years (12 years and 2 months), and males between the ages of 13.3 (13 years and 4 months) and 14.4 (14 years and 5 months). The study by Malina et al. (8) therefore observed a difference in age at PHV between the genders of approx. two years. This observation can be confirmed by the results of the present study, with females in the 1993 and 2013 generations reaching PHV approximately 1.5 years sooner than their male peers. The comparison of PHV attainment between the 1993 and 2013 generations demonstrates that PHV was experienced earlier in the 2013 generation, suggesting an earlier onset of puberty in the most recent generation. In both genders, the age at PHV decreased for 3 months over a twenty-year period on average. This is consistent with findings from other studies from Denmark (18), Sweden (19), Japan (20), and Portugal (21), covering a longer period of 50 years or more, during which time these countries underwent an economic transition similar to Slovenia’s, albeit at a slower pace. There is a lack of data on age at PHV across Eastern and Southern Europe, as most of the studies have focused on age at menarche (e.g. Croatia (22), Poland (23)). In terms of the growth of various parts of the body in human beings, legs are a part of the body, that grow faster than other segments from birth to puberty (5). The leg length of males and females from our study was quite similar to the situation reported for a wider region, e.g. in Croatia in 1997, where leg length at the age of 14 years was 99.0 cm in males (N=225) and 93.8 cm in females (N=209) (24). In most other studies of Eastern Europe (e.g. 25) leg length was obtained by subtracting sitting height from body height, which prevents a direct comparison of results. In our study, the leg-to-body height ratio and leg-to-trunk ratio – the proportion of leg length to trunk length – increased significantly in males over the three generations observed. By contrast, both ratios diminished in females over the course of the same 20- year period. According to the results of the present study, we can reasonably assume that females from the 2013 generation entered puberty sooner than females of previous generations. Moreover, it is most likely that girls from the 2013 generation had already been experiencing the trunk growth stage at the time the measurements were taken, in contrast to previous generations. This is supported by the leg-to-trunk ratio data, which indicates that in the most recent generation of females leg length accounted for a lower percentage of total body height then was the case with females from previous generations. In contrast, the leg length of males from the 2013 generation accounted for a larger percentage of total body height in comparison with males from previous generations. This indicates that, despite their earlier PHV timing, males from the 2013 generation were at an earlier phase of trunk growth than their peers from previous generations, which indicates that pubertal growth intensity was lower than in previous generations. Our results regarding gender-specific changes in trunk and leg growth between adolescents of the same age between 1993 and 2013 (i.e. longer legs in males and longer trunks in females than in previous generations) are consistent with the study conducted by Bowles (26), where sitting height and leg length were compared at the same age between sons and fathers, as well as daughters and mothers, enrolled at Harvard University between 1840 and 1930 (all subjects had a high social status). In this study, sons were taller and heavier, and had a greater leg­to-body height ratio than their fathers, suggesting that, on a relative basis, the greatest change in the length of body segments between the generations appeared in the legs. Daughters were taller and heavier than their mothers, but had a greater trunk-to-body height ratio, suggesting that they had already entered the trunk growth stage. No data on PHV timing was reported for the participants (27). Keyfitz (28) and Meredith and Meredith (29) reported that the mean height of ten-year-old children in 1892, 1923, 1930 and 1939 increased by 1.5 cm per decade. The observed secular trend in body height was caused by several factors. Although healthier diet was a strong factor, it could not be the sole responsible factor, as the same trend has been observed in various societies irrespective of the economic or social status of their individuals (30). In the present study, we did not detect significant differences in body height between the 14-year-old adolescents of the 1993 and 2013 generations. This was true for both genders. Interestingly, the body height of 14-year-old adolescents of the 2003 generation was less than that of the 1993 or 2013 generations. It is possible that the increase in body height in 1993 was superficial and influenced by the large number of child refugees from Bosnia and Herzegovina (31) who attended Slovenian schools in 1993, but who left Slovenia after 1995 (existing evidence shows that the population of Bosnia and Herzegovina is among the tallest in Europe (32)). The overall increase in mean body height between 2003 and 2013 may partly be explained by the process of economic transition, with Slovenia being one of a group of European countries in which significant social and economic changes have taken place in recent decades (33). The transition began in Slovenia in 1991 with the disintegration of the former Yugoslavia, the introduction of consumerism, increased nutritional intake from increased sale of highly processed food, and an increase in sedentary lifestyles resulting from increased use of screen technology. Entry into the European Union in 2004 and the subsequent closing of the gap with wealthier countries resulted in a significant change in GDP: from EUR 11 billion in 1993 to EUR 26 billion in 2003 to EUR 36 billion in 2013 (34). Significant (albeit less drastic) socio­ economic changes were also observable in the decades prior to Slovenia gaining independence (34). In many societies, improved environmental conditions have enabled children to reach their genetic maximum growth potential (7), which is the ability of an individual to reach their theoretical maximum height with proper development, training and nutrition. It has also been reported that puberty begins earlier in children who live in developed countries (35) and whose parents have a good social position (which is determined by good economic status, social power and reputation) (2). Despite the lack of evidence regarding the influence of socio-economic transition on pubertal growth in Eastern Europe, there is evidence that, with economic growth and consequently improved living conditions, the share of children from the region who are short for their age has decreased (36) and their BMI increased (37). Once the conditions for achieving maximum growth potential are established, full body height is probably attained first and earlier development established later. In our study on a sample from Slovenia, a country that is still undergoing economic transition, no significant differences in body height were observed between 14-year-old adolescents born 20 years apart. However, we did observe a trend towards PHV timing in the most recent generation. 4.3 Limitations and Strengths of the Study Limitations of our study were that we examined just as much particiapants to satisfy the criteria for the recommended sample size, furthermore, we did not ask the participants for ethnicity, also we did not determine the Tanner stages for pubertal development, as this is an invasive approach, which would risk higher refusal rates, and self-report approach by the children or their parents would result in 30-40% error. We did not use the same measuring device over 20 years, but we used device of identical standard, and body height was obtained only once a year and therefore also the observed difference in age at PHV. However, on the other hand our study has important strengths, as it is a longitudinal monitoring of children with a large number of different measurements and highly trained measuring team. 4.4 Importance of the Study for Public Health According to the above, we can conclude that our study is important for public health, as it demonstrates that the socio-economic changes in Slovenia, that included a three-time increase in national GDP over the period of 20 years, were profound enough to result in earlier attainment of PHV in adolescents and, through earlier entrance into the period of the trunk growth, a change in body proportions over the observed two-decade period. 4.5 Possibilities for Future Research in the Field In future research it can be reasonably assumed that the difference in age at PHV between generations would be even more pronounced, if the age at PHV could be determined more accurately for each individual, and measuring of sitting height would give us possibility to calculate leg length as substracting sitting height from body height, which would enable comparison of our results with similar studies in other countries. 5 CONCLUSION In 14-year old males, leg-to-body height ratio increased with each decade from 1993 to 2013 due to the increased growth of legs in males and slower overall intensity of pubertal growth despite the earlier PHV timing in the most recent generation. In 14-year-old females, exactly the opposite phenomenon was observed (it was due to trunk growth). The differences in the results between the genders can be explained by the fact that females enter puberty earlier. While they were at the same chronological age as the males, they were, according to the results of this study, already in the trunk growth stage. The present study demonstrates that even when environmental changes occur over a relatively short period of time (20 years in this case), they can affect growth/developmental patterns. The provision of a favourable environment that allows children to achieve their maximum growth potential is therefore of the utmost importance. CONFLICTS OF INTEREST The authors declare that no conflicts of interest exist. FUNDING This paper is part of the Bio-psycho-social contexts of kinesiology project, No P5-0587-142 (1999-2023), which is funded by the Slovenian Research Agency. ETHICAL APPROVAL The project was approved by the National Medical Ethics Committee of the Republic of Slovenia (No 52/03/14) and is in accordance with the Helsinki Declaration. REFERENCES 1. Molnar S. Human variation: races, types and ethnic groups. 6th ed. New Jersey: Pearson Prentice Hall, 2005. 2. Amselem S, Carel JC, De Roux N, Issad T, Maccari S, Prevot V, et al. Growth and puberty: secular trends, environmental and genetic factors. Inserm Collective Expert Reports. 2007. Accessed November 19th, 2019 at: https://www.ncbi.nlm.nih.gov/books/NBK10786/. 3. Spear BA. Adolescent growth and development. In: Rickert VI, editor. Nutrition: assessment and management. New York: Chapman and Hall, 1996;3-24. 4. Bogin B, Varela-Silva MI. Leg length, body proportion, and health: a review with a note on beauty. Int J Environ Res Public Health. 2010;7:1047-53. doi: 10.3390/ijerph7031047. 5. Hermanussen M. Growth in childhood and puberty. In: Kumanov P, Agarwal A. Puberty: physiology and abnormalities. 2016;65-76. doi: 10.1007/978-3-319-32122-6_5. 6. Shephard RJ. Body composition in biological anthropology. Cambridge: University Press, 1991. 7. Rogol AD, Clark PA, Roemmich JN. Growth and pubertal development in children and adolescents: effects of diet and physical activity. Am J Clin Nutr. 2000;72:521S-8S. doi: 10.1093/ajcn/72.2.521S. 8. Malina RM, Bouchard C, Bar-Or O. Growth, maturation, and physical activity. 2nd ed. Illinois: Human Kinetics, 2004. 9. Armstrong N, van Mechelen W. Oxford textbook of children’s sport and exercise medicine. 3rd ed. Oxford: University Press, 2017. 10. Lloyd RS, Oliver JL. The youth physical development model: a new approach to long-term athletic development. J Strength Cond Res. 2012;34:61-72. doi: 10.1519/JSC.0000000000000756. 11. Balyi I, Way R. The role of monitoring growth in long-term athlete development. Canadian Sport for Life, 2005. Accessed November 19th, 2019 at: http://sportforlife.ca/wp-content/uploads/2016/11/ the-role-of-monitoring-growth-in-dlta.pdf. 12. Beunen GP, Rogol AD, Malina RM. Indicators of biological maturation and secular changes in biological maturation. Food Nutr Bull. 2006;27:S244-56. 13. Mirwald RL, Baxter - Jones AD, Bailey DA, Baunen GP. An assessment of maturity from anthropometric measurements. Med Sci Sports Exerc. 2002;34:689-94. 14. Jurak G, Kovac M, Starc G. The ACDSi 2013: The analysis of children’s development in Slovenia 2013: study protocol. Anthropol Noteb. 2013;19:123-43. 15. Lohman TG, Roche AF, Martorell R. Anthropometric standardization reference manual. Illinois: Human Kinetics, 1988. 16. Anon. Oxford Reference. Oxford: University Press, 2015. 17. Tanner JM, Whitehouse RH, Marshall WA, Carter BS. Prediction of adult height from height, bone age, and occurrence of menarche, at ages 4 to 16 with allowance for midparent height. Arch Dis Child. 1975;50:14-26. 18. Aksglaede L, Olsen LW, Sřrensen TI, Juul A. Forty years trends in timing of pubertal growth spurt in 157,000 Danish school children. PLoS One. 2008;3:e2728. doi: 10.1371/journal.pone.0002728. 19. Karlberg J. secular trends in pubertal development. Horm Res. 2002;57:19-30. 20. Ali MA, Lestrel PE, Ohtsuki F. Secular trends for takeoff and maximum adolescent growth for eight decades of Japanese cohort data. Am J Hum Biol. 2000;12:702-12. 21. Cardoso HF, Padez C. Changes in height, weight, BMI and in the prevalence of obesity among 9- to 11-year-old affluent Portuguese schoolboys, between 1960 and 2000. Ann Hum Biol. 2008;35(6):624­ 38. doi: 10.1080/03014460802464200. 22. Prebeg Z. Changes in growth patterns in Zagreb school children related to socio-economic background over the period 1973-1991. Ann Hum Biol. 1998;25(5):425-39. 23. Saczuk J, Wasiluk A, Wilczewski A. Body height and age at menarche of girls from eastern Poland in the period of political transformation. Anthropol Rev. 2018;81(2):130-45. 24. Živicnjak M, Narancic NS, Szirovicza L, Franke D, Hrenovic J, Bisof V. Gender-specific growth patterns for stature, sitting height and limbs length in Croatian children and youth (3 to 18 years of age). Coll Antropol. 2003;27:321-34. 25. Webb E, Kuh D, Peasey A, Pajak A, Malyutina S, Kubinova R, et al. Childhood socioeconomic circumstances and adult height and leg length in central and eastern Europe. J Epidemiol Community Health. 2008;62(4):351-7. doi: 10.1136/jech.2006.056457. 26. Bowles GT. New types of old Americans at Harvard and at eastern women’s colleges. 1st ed. Cambridge: Harvard University Press, 1932. 27. Himes JH. Secular changes in body proportions and composition. In: Roche AF, editor. Secular trends in human growth, maturation, and development. Monographs of the society for research in child development. Chicago: University of Chicago Press, 1979;28-58. 28. Keyfitz NA. A height and weight survey of Toronto elementary school children, 1939. Ottawa: Minister of trade and commerce, 1942. 29. Meredith HV, Meredith EM. The stature of Toronto children half a century ago and today. Hum Biol. 1944;16:126-31. 30. Malina RM. Secular changes in size and maturity: causes and effects. In: Roche AF, editor. Secular trends in human growth, maturation, and development. Monographs of the society for research in child development. Chicago: University of Chicago Press, 1979;59-102. 31. Hadžihalilovic J, Hadžiselimovic R. Growth and development of male children and youth in Tuzla’s region after the war in Bosnia and Herzegovina. Coll Antropol, 2001;25(1):41-58. 32. Gardasevic J, Rasidagic F, Krivokapic D, Corluka M, Bjelica D. Stature and its estimation utilizing arm span measurements in male adolescents from Federation of Bosnia and Herzegovina Entity in Bosnia and Herzegovina. Monten J Sports Sci Med, 2017;6(1):37. 33. Zdešar Kotnik K, Golja P. Changes in body composition of university students in a country in socio-economic transition. Anthropol Anz. 2012;69:261-71. doi: 10.1127/0003-5548/2012/0198. 34. Statistical Office of the Republic of Slovenia, 2019. Accessed November 19th, 2019 at: https://www.stat.si/StatWeb/en/Field/Index/1. 35. Gluckman PD, Hanson MA. Evolution, development and timing of puberty. Trends Endocrinol Metab. 2006;17:7-12. doi:10.1016/j. tem.2005.11.006. 36. Skoufias E. Determinants of child health during the economic transition in Romania. World Dev. 1998;26(11):2045-56. 37. Koziel S, Welon Z, Bielicki T, Szklarska A, Ulijaszek S. The effect of the economic transition on the body mass index of conscripts in Poland. Econ Hum Biol. 2004;2(1):97-106. EVALUATION OF BIOMEDICAL LABORATORY PERFORMANCE OPTIMISATION USING THE DEA METHOD OVREDNOTENJE OPTIMIZACIJE DELOVANJA BIOMEDICINSKIH LABORATORIJEV Z METODO DEA Nejc LAMOVŠEK1*, Maja KLUN2 1University Medical Centre Ljubljana, The Division of Stomatology, Hrvatski trg 6, 1000 Ljubljana, Slovenia 2University of Ljubljana, Faculty of Public Administration, Gosarjeva ulica 5, 1000 Ljubljana, Slovenia Received: Nov 13, 2019 Accepted: Jun 1, 2020 ABSTRACT Keywords: optimisation, biomedical laboratory, DEA method, efficiency, consolidation IZVLECEK Kljucne besede: optimizacija, biomedicinski laboratoriji, metoda DEA, ucinkovitost, konsolidacija Original scientific article Introduction: The Slovenian Resolution on the National Healthcare Plan notes that the country’s medical laboratory activities are fragmented, which may result in cost-inefficiency and a reduction in the quality of the services provided. Defining the efficiency of laboratory service providers can therefore help us to pursue the objectives of the Resolution, i.e. to consolidate and integrate laboratory activities. Methods: Using the DEA method, we conducted an analysis of the efficiency of 20 biomedical laboratories in Slovenia, and made a comparison with a “virtual” laboratory, i.e. a merger of laboratories within a selected organisational unit. By testing different DEA models, we sought to determine whether the use of different input variables caused significant differences in the laboratories’ efficiency scores. Results: The research results show that inefficiency resulting from the size of the units is 1.5 times greater than process inefficiency. Using a non-parametric Wilcoxon Signed Rank test, we determined, at a risk level of 0.05, that there was no difference between the efficiency results when using two different technical efficiency DEA models. When evaluating the virtually merged laboratory, we determined that, under all three models, the virtual laboratory achieved 100% VRS efficiency. However, when the CRS methodology was used, the laboratory showed a certain degree of scale inefficiency. Conclusions: When evaluating merger of medical laboratories we note that the DEA method is methodologically suitable for evaluating the effects of health policy implementation, and is an appropriate tool for identifying where the field of laboratory medicine might be further developed and improved. Namen: Resolucija o nacionalnem planu zdravstvenega varstva v Sloveniji ugotavlja, da je medicinska laboratorijska dejavnost pri nas razdrobljena, kar ima lahko za posledico slabšo kakovost opravljenih storitev in stroškovno neucinkovitost laboratorijev. Opredelitev ucinkovitosti izvajalcev laboratorijskih storitev lahko tako pomaga zasledovati cilje resolucije, tj. konsolidacijo in integracijo laboratorijske dejavnosti. Metode: Z metodo analize ovojnice podatkov (metoda DEA) smo opravili analizo ucinkovitosti dvajsetih biomedicinskih laboratorijev v Sloveniji ter primerjavo z navideznim laboratorijem, ki predstavlja združitev laboratorijev v izbrani organizacijski enoti. S preizkusom razlicnih vhodno orientiranih modelov DEA smo želeli ugotoviti, ali zaradi uporabe razlicnih vhodnih spremenljivk obstajajo bistvene razlike pri dolocitvi koncne ucinkovitosti laboratorijev. Dolocili smo tako tehnicno kot tudi stroškovno ucinkovitost biomedicinskih laboratorijev. Rezultati: Rezultati raziskave kažejo, da je na primeru analiziranih laboratorijev kar 1,5-krat višja neucinkovitost, ki izhaja iz velikosti obravnavanih enot, od procesne neucinkovitosti. Z uporabo neparametricnega testa Wilcoxon Signed Rank smo pri stopnji tveganja 0,05 ugotovili, da ne obstaja razlika med rezultati ucinkovitosti z uporabo dveh razlicnih modelov dolocanja tehnicne ucinkovitosti. Pri oceni navidezno združenega laboratorija smo ugotovili, da navidezni laboratorij dosega 100-odstotno cisto tehnicno ucinkovitost, vendar pa pri uporabi metodologije CRS izkazuje doloceno stopnjo neucinkovitosti in tudi ni na meji proizvodnih možnosti. Zakljucek: Kadar ocenjujemo vplive združevanja medicinskih laboratorijev ugotavljamo, da je metoda DEA metodološko primerna za evalvacijo ucinkov izvajanja zdravstvene politike ter tudi ustrezno orodje za opredelitev nadaljnjega razvoja in izboljšav na podrocju laboratorijske medicine. *Corresponding author: Tel. + 386 51 267 246; E-mail: nejc.lamovsek@gmail.com © National Institute of Public Health, Slovenia. 1 INTRODUCTION For centuries, laboratory medicine has been one of the most important factors in providing proper patient care and promoting technological development in the field of medicine. The development of automation and information technology has led to the development of sensitive and specific laboratory tests that are invaluable to doctors when diagnosing and confirming diseases (1, 2). As a part of the public healthcare network, medical laboratories provides services that directly affect patients; furthermore, it provide services to other stakeholders, i.e. healthcare professionals, healthcare payers and health policy-makers (3). While the tendency to improve quality and productivity in the field of laboratory medicine is a constant one, it is important to bear in mind the constraints, which include staff shortages and limited funding. It is these constraints that compel laboratory managers to constantly consider introducing work processes and technologies that could optimise laboratory organisation and performance (4). The issue of achieving efficiency is considered to be one of the most important intermediate objectives of health system effectiveness (5). Achieving efficiency in healthcare is often equated with the introduction of a free market economy, which can affect equal access to services, fairness in resource allocation and the achievement of quality standards (6). As a result of this dilemma, laboratory activities are treated differently in different systems. When measures to improve efficiency are adopted, a great deal of attention is devoted to laboratory concentration, which is essential if capacity is to be better utilised. The efficiency of public service providers can be determined by means of different methods. However, data envelopment analysis (DEA) is one of the most commonly used methods in the field of healthcare (7, 8). The introduction of management systems, management processes and resource management planning aimed at improving efficiency in the healthcare sector is an important element in reducing costs and increasing productivity in healthcare organisations (9). One further aspect can be considered when our aim is to achieve greater efficiency, namely the use of technology in business processes. Technological development means that there is an increased need for greater specialisation of work, which leads to shorter turnaround times in laboratory medicine. In such cases, innovative ideas can significantly boost the efficiency and effectiveness of biomedical information systems (10). The laboratory work process is divided into several important and interconnected phases. By using the ABC process diagram, we can describe the individual phases in laboratory workflow (11, 12). One of the most important aspects of the renewal of work processes in the field of laboratory medicine is the introduction of functional automation. The merging of laboratories into a central hospital laboratory reduces overall costs because the number of biomedical analyzers (and therefore the associated labour costs) can be reduced (13). Our conclusion is that work process improvements resulting from the consolidation of laboratories and the determination of surpluses in the inputs used can only be identified through a thorough knowledge of the work process in biomedical laboratories. The aim of our study is to determine the efficiency of biomedical laboratories by testing different specifications of DEA models. Our research question is whether the consolidation of laboratory activity can increase laboratory efficiency and, at the same time, reduce the costs allocated to laboratory services. The study also aims to evaluate the effects of a potential merged biomedical laboratory, and offer an optimally constructed biomedical laboratory at the tertiary healthcare level. The study is based on data from 20 biomedical laboratories in Slovenia. 1.1 Definition of Laboratory Activities and their Necessary Development in Slovenia Slovenian health policy is determined by the Resolution on the National Healthcare Plan 2016–2025 (“Together for a Healthy Society”), the Health Services Act, and the Healthcare and Health Insurance Act. The Resolution identifies laboratory medicine as part of the health network and as an important factor in ensuring proper, high- quality patient management. It also notes that laboratory activities in Slovenia are fragmented and that they fail to provide sufficient test concentration; this results in incomparability of laboratory test results between individual laboratories and may lead to a reduction in the quality of the services provided and to cost inefficiency. One of the objectives of the Resolution is therefore to highlight the need to integrate and consolidate laboratory activities (14). Slovenian experts in the field of laboratory medicine have identified the non-consolidation of laboratories and indirect payment for laboratory services as the main problems currently being faced. The consolidation and coordination of laboratories and the introduction of direct payment for laboratory services were identified as possible solutions to the current situation (15). According to the records of the Ministry of Health, Ljubljana University Medical Centre (UKC) has eight separate biochemical laboratories, each under its own organisational unit. The Merged Laboratories Project, which aims to bring together the four largest UKC medical laboratories under one organisational unit and one location, is currently under way at the hospital. 1.2 Literature Review Among the most widely used methods for efficiency analysis are ratio analysis, total productivity factor, the least squares method (COLS), stochastic frontier analysis (SFA) and data envelope analysis (DEA). The DEA method offers some advantages – specifically, an empirically determined frontier of production possibilities without a predetermined production function, and the possibility of creating goals for less efficient units (16). A few healthcare DEA efficiency studies in the field of primary medical care (17-19) do exist, and they all come to a similar conclusion: that smaller primary healthcare centres are more scale inefficient. DEA efficiency studies of hospitals at the secondary healthcare level (5, 20-22) are also quite common. The results of the studies suggest that an understanding of hospital functioning, together with the results obtained from efficiency studies, can help us determine optimal hospital size. While efficiency research has not been conducted to any great extent in the field of laboratory medicine, there are studies (23, 24) that identify laboratory efficiency using the DEA methodology and that provide a basis for the further development of efficiency research in laboratory activities. Research on the impact of hospital mergers on determining hospital efficiency and potential surpluses in the inputs used is also important for our study. Efficiency improvements can usually only be achieved by improving scale efficiency (25–28). Several studies use virtual hospital mergers as a tool to show the differences between unconsolidated and combined hospital activity (25, 27, 29). However, (30) identifies, in theoretical and methodological terms, the contributions of the virtually merged unit model used. This indicates the possibility of using the method of virtual merger of DMUs as a tool for identifying potential improvements and defining surpluses in the inputs used at potentially merged biomedical laboratories. 2 METHODOLOGY Historically, the development of methods for assessing efficiency began with Debreu (1951), Koopmans (1951) and Farrell (1957), who laid the foundations for assessing the relative efficiency of DMUs (decision making units). A technically efficient input-oriented manufacturer therefore produces a constant output by minimising production factors. The appropriate ratio of inputs in terms of their price further defines allocative efficiency. Economic efficiency is a product of both technical and allocative efficiency (7, 26, 31). In 1978 Charnes developed a linear program based on a non-linear program, i.e. a DEA method for analysing the efficiency of DMUs. The method has become particularly well-established in the public sector, since the frontier of linearly linked segments is determined on the basis of empirical data without a pre-specified production function. The CRS (constant return to scale) or VRS (variable return to scale) model can be used in the analysis to predict the technology used (7, 8, 32). The input-oriented CRS model can be mathematically presented in the form of a linear program derived from a fundamental fractional program. The CRS model (Eq, 1), also named the CCR model, is a constant return model and is for n DMUs, of which each DMUj uses m inputs xij, (i=1,...,m) and s outputs yrj, (i=1,...,s), written in linear form (33). Eq.1 Values yrj, and xij are the given values of outputs and inputs, indicating past operating results. Values µr and vi are variable weights enabling each unit to be weighted for its optimal benefit function within the given limitations, determined by the values of variable y and x with all units. Efficient units are those that reach the ratio 1. The definition is written in the input form; therefore, the proportionally inefficient units reach the ratio <1. The difference between the CRS and VRS models is present in the free variable, which is a dual variable associated with the constraint. The CRS therefore represents technical (cost) efficiency, while the VRS result represents pure technical (cost) efficiency. Scale efficiency (SE) is a ratio between CRS and VRS efficiency and enables us to define whether the cause of inefficiency lies in the non optimal size of the observed unit. We can also define cost-based scale efficiency (CSE). DEA research on efficiency in healthcare is mostly input- oriented; this is because healthcare managers only control used resources, which is also supported by systematic reviews of DEA research (16, 34). The selection of input and output variables was based on the research (23, 24, 35, 36). Laboratory output is produced by means of capital, labour and the use of consumables. In all the models presented, we define output as the number of basic, special and reference tests. Therefore, in our case, Model 1 (M1) represents the number of working hours, the number of biomedical analyzers, and the cost of laboratory material and reagents. Model 2 (M2) represents the number of working 10.2478/sjph-2020-0022 hours, the total purchase price of laboratory equipment, and the cost of laboratory materials and reagents. The cost model (M3) is defined by labour costs and the cost of laboratory material and reagents. In the technical efficiency model, we tried to determine whether there was a difference in determining technical efficiency by using a different capital input. Because laboratories have more control over the inputs they consume than the outputs they produce, we used the input-oriented CRS and VRS DEA method to determine the efficiency of medical laboratories with an additional calculation of SE. By determining the surplus in the inputs used, we quantified the redundant resources used. We constructed a virtual laboratory, based on the expected merger of four UKC laboratories at a single location, which consists of the sum of the actual values of the inputs and outputs of the four UKC laboratories. Using an ABC laboratory work process chart, we identified individual phases within which the work process could be optimised. 2.1 Empirical Data and Analysis In our research, we determined the efficiency of laboratory service providers in Slovenia at the primary, secondary and tertiary healthcare levels. Eleven hospital biochemical laboratories (B), the laboratories of three tertiary institutions (T) and three major laboratories at the primary level (Z) were included in the study. All four UKC laboratories slated for merger were included in the analysis. The data for our research is not publicly available, and we obtained it from public healthcare institutions solely for the purposes of our research. We analysed data from 20 Slovenian medical laboratories for 2017. Due to the restricted set of laboratories analysed and the use of multiple inputs and outputs, our estimation of laboratory efficiency could potentially be higher than it actually is. Data for our study was analysed using the Frontier program and the SPSS statistical program. Table 1. Statistical analysis. Zdr Varst. 2020;59(3):172-179 The smallest B1 laboratory has six employees who carry out a total of 7,458 effective working hours. The largest T1 laboratory has 107 laboratory workers who carry out the largest number of basic laboratory tests annually, i.e. 5,616,624. Its labour costs are EUR 2,290,144. The labora­ tories have 21 biomedical analyzers on average and spend an average of EUR 942,724.43 on reagents and laborato­ ry material. A certain degree of expected heterogeneity is present on the side of output, since SDs may be 50% higher than average values. As is apparent from the value of the outputs, heterogeneity is present because of the specialised services of individual health institutions that go beyond the scope and sphere of influence of laborato­ry activity, which adjusts the range of laboratory tests it offers and performs. 3 RESULTS Table 2 shows the results of efficiency analysis using the CRS and VRS methodologies. As the aim of our study is to determine the optimal size of the merged UKC laboratory, we will primarily focus on presenting the results of the UKC laboratories in defining the results of the analysis. Min. Max. Average SD INPUTS Number of working hours Number of biomedical analyzers Cost of laboratory equipment Labour costs Cost of laboratory reagents and material 7,458 6 49,616 97,332.54 134,683 157,746 68 2,437,057 2,290,144 4,520,071 42,604.85 21 601,112.50 657,896.07 942,724.43 35,947.78 16 590,995.57 591,933.26 945,991.67 OUTPUTS Number of basic tests Number of special tests Number of reference tests 49,985 2,651 24 5,616,624 784,245 111,940 941,786.90 121,054.15 18,066.60 1,277,335.30 170,071.16 26,016.38 Source: own. Table 2. Efficiency results. Model 1 Model 2 Model 3 DMU CRS (%) VRS (%) RTS SE (%) CRS (%) VRS (%) RTS SE (%) CRS (%) VRS (%) RTS SE (%) B1 34.93 100 1 34.93 39.86 100 1 39.86 37.26 100 1 37.26 B2 38.78 68.93 1 56.26 45.25 71.79 1 63.03 40.36 66.74 1 60.47 B3 100 100 - 100 100 100 - 100 100 100 - 100 B4 100 100 - 100 100 100 - 100 100 100 - 100 B5 69.81 88.59 1 78.80 70.54 80.64 1 87.48 64.05 73.40 1 87.26 B6 100 100 - 100 100 100 - 100 100 100 - 100 B7 100 100 - 100 78.08 86.62 1 90.14 55.75 60.32 1 92.42 B8 75.14 86.14 1 87.23 80.15 90.16 1 88.90 71.74 74.01 1 96.93 B9 64.53 77.56 1 83.20 66.66 79.06 1 84.32 63.83 75.18 1 84.90 B10 88.82 97.37 1 91.22 99.94 100 1 99.94 89.61 100 1 89.61 B11 100 100 - 100 81.03 96.73 1 83.77 97.54 100 1 97.54 Z1 100 100 - 100 100 100 - 100 87.36 100 -1 87.36 Z2 76.90 77.56 -1 99.15 86.97 87.34 1 99.58 76.9 77.56 -1 99.15 Z3 66.40 96.40 1 68.88 75.73 100 1 75.73 66.4 100 1 66.40 T1 100 100 - 100 100 100 - 100 100 100 - 100 T2 72.28 100 1 72.28 92.33 100 1 92.33 77.62 100 1 77.62 T3 100 100 - 100 100 100 - 100 100 100 - 100 T4 80.87 87.49 1 92.43 77.59 79.57 1 97.51 46.14 52.87 1 87.27 T5 60.04 72.64 1 82.65 60.04 72.64 1 82.65 58.44 67.17 1 87 T6 100 100 - 100 100 100 - 100 100 100 - 100 x(%) 81.43 92.63 87.35 82.71 92.23 89.26 76.65 87.36 87.56 SD 21.01 10.60 17.79 18.87 10.29 15.42 21.78 16.68 16.38 Source: own. As Table 2 shows, the average technical efficiency of lab­oratories under Model 1 is 81.43%. As expected, average pure technical efficiency is higher (92.63%). Under Model 2, we observe higher average technical efficiency than un­der Model 1 (82.71%). However, the average pure technical efficiency is lower (92.23%). A comparison between labo­ratories when using the two models shows that SD is the highest in CRS technology prediction, i.e. for laboratories B11 and T2. Table 2 shows that, when using cost Model 3, the aver­ age cost-efficiency score is, as predicted, lower (76.65%) than the technical efficiency score. Similarly, we observe a pure cost-efficiency score (87.36%) that is lower than the pure technical efficiency score. We can establish that the laboratories observed show scale inefficiency that is 1.5 times higher than process in­efficiency. This suggests that in the laboratories examined in our study, a greater share of inefficiencies result from suboptimal laboratory size than from the way laborato­ries work. They could therefore improve their technical efficiency mainly by adjusting their process size. The B3, B4, B6, T1, T3, Z1 and T6 laboratories are both CRS- and VRS-efficient, which means that they are of optimal size. They form the frontier of production possibilities in the use of both models and, furthermore, the B7 and B11 labo­ratories are scale efficient under Model 1. The lowest effi­ciency was observed in connection with the B1 laboratory under all three efficiency models. Our simulation was carried out in response to the planned merger of laboratories T1, T2, T3 and T4. The merging of these laboratories is therefore easier to carry out because the laboratories already operate within a single institu­tion. The potential consolidation of other laboratories in our analysis could be based on their geographical proxim­ity. The T1 and T3 laboratories are efficient when using both the CRS and VRS methodologies, which means they are also of optimal size. The T2 laboratory does not show process inefficiency when using Model 1. All inefficiency results from incorrect size. As the RTS of laboratories T2 and T4 is increasing, they could only achieve scale efficien­cy by increasing their size. This could be achieved through an increase in the resources used, as well as through a proportional increase in the number of laboratory tests provided. Model 2 produces a similar result. In terms of determining technical efficiency, the potential merger of the T1, T2, T3 and T4 laboratories would have a positive impact, mainly due to the more optimal size of the T2 and T4 laboratories, which would now be part of a larger laboratory. A comparison between the technical efficiency and cost-efficiency of the laboratories shows that the T4 lab­oratory has the biggest difference (34%). Further analysis should be carried out to determine whether the cause of the inefficiency may lie in the sub-specialisation of the T4 laboratory. We used the Wilcoxon Signed Rank non-parametric test to determine statistical difference in the efficiency results. Using a significance level of 0.05, we established that the efficiency results for the two technical efficiency models in the case of our sample were not different (W 25>W critical 14). Table 3. Efficiency of the virtually merged laboratory. MODEL 1 Pseudo 1 93.33 100 -1 93.33 MODEL 2 Pseudo 2 95.89 100 -1 95.89 MODEL 3 Pseudo 3 89.60 100 -1 89.60 x 92.94 100 92.94 SD 3.16 0 3.16 As Table 3 shows, a virtually merged laboratory (Pseudo) would achieve 100% VRS efficiency under all three mod­els. However, the laboratory shows a certain degree of scale inefficiency when the CRS methodology is used. The size of the process in the consolidated laboratory would be too large from the standpoint of decreasing returns to scale (RTS). The laboratory should reduce the amount of inputs it consumes and maintain the level of outputs produced. Despite the relatively low level of inefficien­cy identified, the surpluses in inputs used would be high, mainly due to the size of the merged laboratory. Taking the economic efficiency theory into account, we further defined the surpluses in inputs and deficits in outputs produced at the virtual laboratory. The values of the surpluses were defined using the DEA method, i.e. by predicting the optimal size of the laboratory. However, one should be aware that our set of analysed laboratories shows a certain degree of heterogeneity, which can make it more difficult to accurately estimate the target values of the input variables. A virtual laboratory could reduce the number of working hours by 16,686.01, labour costs by EUR 374,852.16, the number of analyzers by 11, the pur­chase price of laboratory equipment by EUR 205,256.91, and the cost of laboratory materials and reagents by EUR 1,265,576.49. On the output side, the laboratory could carry out 860,520 more basic laboratory tests and 112,344 more specialised laboratory tests. A laboratory construct­ed in such way would achieve and create a new produc­tion possibility frontier through the use of both CRS and VRS methodologies. We used the ABC flowchart to show the work process in the laboratory. The essential stages of the process are: test ordering, admission of sample, sample triage, anal­ysis, result validation, and the issuing of accurate and high-quality laboratory results. Organisational chart 1. Work process in the laboratory. Based on knowledge of the work process in medical lab­oratories, we suggested the process improvements in individual phases of laboratory work that could possibly result from the consolidation of laboratories (Organisa­tional chart 1). Irrespective of the number of collected samples, laboratories must ensure continued presence of trained laboratory personnel at the sample collection and admission point. A reduction in the workforce could be accomplished by unifying sample collection as well as sample admission points. Different biomedical analyzers are required to perform different diagnostic laboratory tests. In the case of scale inefficient laboratories, this fails to achieve a sufficiently high level of analyzers utili­sation. Despite lower analyzers utilisation, daily, monthly and annual maintenance of devices must be carried out, along with the daily testing of control material. This pre­sents additional costs resulting from the consumption of laboratory materials and reagents. In our study, we ob­ serve that automation can improve laboratory efficiency only if biomedical analyzers are fully utilised, something that can be achieved if laboratories are of the appropriate size. The merging of laboratories within a single health organisation would therefore lead to lower purchase pric­es through the joint procurement of laboratory reagents and materials, and biomedical analyzers. The uniform use of diagnostic equipment ensures greater comparability of results, and thus directly affects the quality and reliability of the laboratory findings issued. The envisaged merger of laboratories would result in greater specialisation of work tasks. Added value also represents the implementation of special tests and research activities. In the case of separate laboratories, only larger laborato­ries have their own support staff, i.e. administration and service personnel. Administrative tasks in smaller labora­tories are carried out by laboratory workers. Rationalisa­tion of the number of support staff, i.e. service personnel and administration, would reduce labour costs in the con­solidation process. 4 DISCUSSION Under the Slovenian Resolution on the National Healthcare Plan, laboratory activity is unconsolidated. This adversely affects the concentration of the laboratory tests conduct­ ed, the quality of work and, not least, the technical and cost-efficiency of laboratories. The DEA method enables us to identify best practices and to quantify the surpluses in the inputs used. By calculating scale efficiency, we can further determine whether the cause of the inefficiency lies in the size of the unit analysed or the results of the process inefficiencies. While a constructed, virtually merged laboratory does not show process inefficiency, it does show some degree of scale inefficiency. Similarly, studies on hospital mergers show the importance of determining the optimal size of hospitals in their merger (26, 27). In light of the findings of these studies, we also observe that, due to the decreas­ing RTS, merged laboratories should reduce the resources used. The biggest advantage of merged laboratories is the reductions they bring in the cost of laboratory reagents and materials. Work process optimisation resulting from a more appropriate laboratory size would have a posi­tive impact on achieving economies of scale. In this part, therefore, our study concurs with previous findings (13). Similarly, the results of our study show that labour costs, the costs of laboratory reagents and materials and the number of biomedical analyzers used would be reduced. The merged laboratory could thus reduce labour costs by 10% and the costs of laboratory reagents and materials by 17%. Labour force optimisation could be accomplished by unifying sample collection points, as well as admission and management staff at the laboratory. The harmonisation of technology used at the same location would consequently lead to greater utilisation of laboratory equipment and im­prove the comparability of the laboratory tests provided. 5 CONCLUSIONS An evaluation of the efficiency of medical laboratories should be in the interest of health service payers and health policy-makers alike. We can conclude that efficien­cy evaluations are indispensable when planning a network of laboratory services, i.e. consolidation of laboratory services. We note, like other researchers who have used the DEA method to evaluate health policy and reform (37, 38), that the method is methodologically suitable for evaluat­ing the effects of health policy implementation, and is an appropriate tool for identifying further development and improvements in the field of laboratory medicine. The re­sults of the analysis can help public healthcare institution managers to identify surpluses in the inputs used and the resulting process optimisation. If decision-makers want easily accessible laboratory ser­vices, they must accept that this has a negative impact on the optimal performance of smaller medical laboratories (because their size is non-optimal). In conclusion, we must ask ourselves how much efficiency we are willing to sac­rifice to ensure that health services are accessible to the greatest possible extent. The main gap in the study is its inability to identify cost-ef­ ficiency using several models because public healthcare institutions’ records are incomplete, particularly the as­pect that defines capital cost. An international compar­ison of the models used to determine efficiency would provide additional benefits to this field of study. CONFLICTS OF INTEREST The authors declare that no conflicts of interest exist. FUNDING None. ETHICAL APPROVAL All data used in this study was provided by Slovenian lab­oratories. All personal data was anonymised. REFERENCES 1. Delwiche FA. Mapping the literature of clinical laboratory science. J Med Libr Assoc. 2003;91(Suppl 3):303-10. 2. Berger D. A brief history of medical diagnosis and the birth of the clin­ical laboratory part 1: ancient times through the 19th century. MLO Med Lab Obs. 1999;31(Suppl 7):28-30. 3. Price CP, John AS, Christenson R, Scharnhorst V, Oellerich M, Jones P, et al. Leveraging the real value of laboratory medicine with the value proposition. Clin Chim Acta. 2016;462:183-6. doi: 10.1016/j. cca.2016.09.006. 4. Croxatto A, Greub G. Project management: importance for diagnostic laboratories. Clin Microbiol and Infect. 2017;23(Suppl 7):434-40. doi: 10.1016/j.cmi.2017.04.007. 5. Sahin I, Ozcan YA, Ozgen H. Assessment of hospital efficiency un­der health transformation program in Turkey. Cent Eur J Oper Res. 2011;19(Suppl 1):19-37. doi: 10.1007/s10100-009-0121-3. 6. Brandăo C, Rego G, Duarte I, Nunes R. Social Responsibility: A New Paradigm of Hospital Governance? Health Care Anal. 2013;21(Suppl 4):390-402. 7. Ozcan YA. Health care benchmarking and performance evaluation: an assessment using data envelopment analysis (DEA). New York: Spring­er, 2008. 8. Zhu J. Quantitative models for performance evaluation and bench­marking: data envelopment analysis with spreadsheets. Berlin: Spring­er, 2014. 9. Helfert M. Challenges of business processes management in health-care: experience in the Irish healthcare sector. Bus Process Manag J. 2009;15(Suppl 6):937-52. doi: 10.1108/14637150911003793. 10. Stefanelli M. Knowledge and process management in health care or­ganizations. Methods Inf Med. 2004;43(Suppl 5):525-35. 11. World Health Organization. Laboratory quality management system: handbook. Lyon: WHO Office, 2011:9-11. 12. Inal, T. C., Goruroglu Ozturk, O., Kibar, F., Cetiner, S., Matyar, S., Daglioglu, et. al. Lean six sigma methodologies improve clinical lab­oratory efficiency and reduce turnaround times. J Clin Lab Anal. 2018;32(Suppl 1):e22180. doi: 10.1002/jcla.22180. 13. Archetti C, Montanelli A, Finazzi D, Caimi L, Garrafa E. Clinical labo­ratory automation: a case study. J Public Health Res. 2017;16;6(Suppl 1). doi: 10.4081/jphr.2017.881. 14. Skupaj za družbo zdravja: resolucija o nacionalnem planu zdravstven­ega varstva 2016-2025. Ljubljana: Ministrstvo za zdravje RS, 2018. 15. Lužnik-Avberšek, I. Možina, B. Organization and strategy of labora­tory medicine in Slovenia – proposals of improvement. Proceedings of the conference. Ljubljana: Slovenian Association for Clinical Chemis­try, 2013:16-17. 16. Pelone F, Kringos DS, Romaniello A, Archibugi M, Salsiri C, Ricciar­di W. Primary care efficiency measurement using data envelopment analysis: a systematic review. J Med Syst. 2015;39(Suppl 1):156. doi: 10.1007/s10916-014-0156-4. 17. Cordero Ferrera JM, Crespo Cebada E, Murillo Zamorano LR. The ef­fect of quality and socio-demographic variables on efficiency meas­ures in primary health care. Eur J Health Econ. 2014;15(Suppl 3):289­ 302. doi: 10.1007/s10198-013-0476-1. 18. Kontodimopoulos N, Moschovakis G, Aletras VH, Niakas D. The effect of environmental factors on technical and scale efficiency of primary health care providers in Greece. Cost Eff Resour Alloc. 2007;17(Suppl 5):14. doi: 10.1186/1478-7547-5-14. 19. Luoma K, Järviö M, Suoniemi I, Hjerppe RT. Financial incentives and pro­ductive efficiency in Finnish health centres. Health Econ. 1996;5(Sup­pl 5):435-45. doi: 10.1002/(SICI)1099-1050(199609)5:5<435::AID­HEC223>3.0.CO;2-Y. 20. Giancotti M, Rotundo G, Pipitone V, Mauro M. Efficiency and opti­mal size of Italian public hospitals: results from data envelopment analysis. Epidemiol Biostat Public Health. 2018;15(Suppl 4):13. doi: 10.2427/12929. 21. Harrison JP, Meyer S. Measuring efficiency among us federal hos­pitals. Health Care Manag. 2014;33(Suppl 2):117-27. doi: 10.1097/ HCM.0000000000000005. 22. Blatnik P, Bojnec Š, Tušak M. Measuring efficiency of secondary healthcare providers in Slovenia. Open Med. 2017;12:214-25. doi: 10.1515/med-2017-0031. 23. Taheri A, Shayan Jahromi SA, Lotfi F. Efficiency of clinical laboratories affiliated in shiraz university of medical sciences in 2015: an applica­tion of data envelopment analysis. Int J Health Stud. 2016;4:21-4. doi: 10.22100/ijhs.v2i4.176. 24. Vitezic N, Šegota A, Setnikar Cankar S. Measuring the efficiency of public health services by DEA. Int Public Admin Rev. 2017;14:27-48. doi: 10.17573/ipar.2016.4.02. 25. Kjekshus L, Hagen T. Do hospital mergers increase hospital efficiency? Evidence from a national health service country. J Health Serv Res Policy. 2007;12(Suppl 4):230-5. 26. Harris J, Ozgen H, Ozcan Y. Do mergers enhance the performance of hospital efficiency? J Operat Res Society. 2000;51(Suppl 7):801-11. doi: 10.1057/palgrave.jors.2600869. 27. Ferrier G, Valdmanis V. Do mergers improve hospital productivity? J Operat Res Soc. 2004;55(Suppl 10):1071-80. doi: stable/4101953. 28. Giancotti M, Guglielmo A, Mauro M. Efficiency and optimal size of hospitals: results of a systematic search. PLoS One. 2017;12(Suppl 3):e0174533. doi: 10.1371/journal.pone.0174533. 29. Sinay T, Campbell CR. Strategies for more efficient performance through hospital merger. Health Care Manage Rev. 2002;27(Suppl 1):33–49. doi: 10.1097/00004010-200201000-00004 30. Bogetoft P, Wang D. Estimating the potential gains from mergers. J Prod Anal. 2005;23(Suppl 2):145-71. doi: 10.1007/s11123-005-1326-7. 31. Došenovi P. Inovacije kot dejavnik ucinkovitosti in uspešnosti bolnišnic v Sloveniji: doctoral thesis. Ljubljana: Univerza v Ljubljani, 2010. 32. Jacobs R, Smith PC, Street A. Measuring efficiency in health care: ana­lytic techniques and health policy. Cambridge: University Press, 2006. 33. Cook WD, Seiford LM. Data envelopment analysis (DEA)-thirty years on. Eur J of Oper Res. 2009;192(Suppl 1):1-17. doi: 10.1016/j. ejor.2008.01.032. 34. Cantor VJM, Poh KL. Integrated analysis of healthcare efficiency: a systematic review. J Med Syst. 2018;42(Suppl 1):8. doi: 10.1007/ s10916-017-0848-7. 35. Lamovšek N, Klun M, Skitek M, Bencina J. Defining the optimal size of medical laboratories at the primary level of health care with data envelopment analysis: defining the efficiency of medical lab­oratories. Acta Inform Med. 2019;27(Suppl 4):224-8. doi: 10.5455/ aim.2019.27.224-228. 36. Lamovšek, N., Klun, M. (2020). Efficiency of medical laboratories af­ter quality standard introduction: trend analysis of EU countries and case study from Slovenia. CEPAR. 18(Suppl 1), 143-63. doi: 10.17573/ cepar.2020.1.07. 37. Zavras AI, Tsakos G, Economou C, Kyriopoulos J. Using DEA to eval­uate efficiency and formulate policy within a Greek national prima­ry health care network. J Med Syst. 2002;26(Suppl 4)285-92. doi: 10.1023/a:1015860318972. 38. Shrime MG, Mukhopadhyay S, Alkire BC. Health-system-adapted data envelopment analysis for decision-making in universal health cover­ age. Bull World Health Organ. 2018;96(Suppl 6):393-401. doi: 10.2471/ BLT.17.191817. WELL-BEING AND SATISFACTION OF NURSES IN SLOVENIAN HOSPITALS: A CROSS-SECTIONAL STUDY POCUTJE IN ZADOVOLJSTVO MEDICINSKIH SESTER V SLOVENSKIH BOLNIŠNICAH: PRESECNA RAZISKAVA Mateja LORBER1*, Sonja TREVEN2, Damijan MUMEL2 1University of Maribor, Faculty of Health Sciences, Žitna ulica 15, 2000 Maribor, Slovenia 2University of Maribor, Faculty of Economics and Business, Razlagova 14, 2000 Maribor, Slovenia Received: Oct 2, 2019 Accepted: Jun 8, 2020 ABSTRACT Keywords: hospitals, nurses, satisfaction, health IZVLECEK Kljucne besede: bolnišnice, medicinske sestre, zadovoljstvo, zdravje Original scientific article Introduction: Well-being is one of the most important factors in whether nurses decide to remain in the nursing profession. This study aims to examine well-being and satisfaction among nurses working in Slovenian hospitals and to identify the related demographic factors. Methods: This descriptive cross-sectional study uses standardised instruments. The sample included 640 nurses working in Slovenian hospitals. The difference between individual variables were analysed using the Mann-Whitney and Kruskal-Wallis tests. Results: Nurses self-assessed their satisfaction and well-being as moderate. Forty-seven per cent of nurses were satisfied with their job, 49% assessed their psychological well-being as good, 52% were often exposed to stress at the workplace and 30% were always exposed to stress at the workplace. Levels of job satisfaction (p=0.031), psychological well-being (p=0.029) and subjective well-being (p=0.014) were found to differ significantly according to level of education, while levels of job satisfaction (p=0.005), life satisfaction (p<0.001), psychological well­being (p<0.001) and subjective well-being (p<0.001) were also found to differ according to years of nursing service and from hospital to hospital (p<0.001). Conclusions: The key finding of the study is that nurses are moderately satisfied with their work and life and that they display moderate levels of psychological and subjective well-being. Hospitals can be successful and achieve the goals of the organisation if their employees are satisfied with work and enjoy good levels of well-being. Hospital management have to recognise the importance of ensuring that nurses and other employees are satisfied and healthy. Uvod: Pocutje medicinskih sester je eden najpomembnejših dejavnikov odlocitve, ali ostanejo zaposlene v zdravstvu ali ne. Namen raziskave je bil ugotoviti stopnjo dobrega pocutja in zadovoljstva medicinskih sester, ki delajo v slovenskih bolnišnicah, ter prepoznati nekatere povezane demografske dejavnike. Metode: Uporabljena je bila opisna presecna raziskava in standardizirani instrumenti. V vzorec je bilo vkljucenih 640 medicinskih sester iz slovenskih bolnišnic. Razlike med posameznimi spremenljivkami so bile analizirane s testoma Mann-Whitney in Kruskal-Wallis. Rezultati: Medicinske sestre so samoocenile svoje zadovoljstvo in pocutje kot zmerno. 47 % medicinskih sester je zadovoljnih s svojim delom, 49 % pa je svoje psihološko pocutje ocenilo kot pozitivno. 52 % medicinskih sester je pogosto in 30 % medicinskih sester je vedno izpostavljenih stresu na delovnem mestu. Glede na stopnjo izobrazbe so bile ugotovljene statisticno pomembne razlike v zadovoljstvu z delom (p = 0,031), psihološkem (p = 0,029) in subjektivnem pocutju (p = 0,014). Statisticno pomembne razlike so bile ugotovljene pri zadovoljstvu z delom (p = 0,005), zadovoljstvu z življenjem (p < 0,001), psihološkem (p < 0,001) in subjektivnem pocutju (p < 0,001) glede na leta delovnih izkušenj v zdravstveni negi in upoštevajoc razlicne bolnišnice (p < 0,001). Zakljucki: Kljucna ugotovitev raziskave je zmerno zadovoljstvo z delom in življenjem ter zmerno dobro psihološko in subjektivno pocutje medicinskih sester. Bolnišnice so lahko uspešne in dosegajo organizacijske cilje, ce so tudi medicinske sestre zadovoljne z delom in se dobro pocutijo. Vodstvo v bolnišnicah mora prepoznati pomen skrbi za zadovoljne in zdrave medicinske sestre ter tudi ostale zaposlene v bolnišnici. *Corresponding author: Tel. + 386 2 300 47 53; E-mail: mateja.lorber@um.si © National Institute of Public Health, Slovenia. 1 INTRODUCTION Healthcare systems face a shortage of nurses and increasing demands for patient care (1). The work-related demands on nurses are high (2) and their work is emotional and physically demanding (3). Nursing is becoming an increasingly stressful occupation (4), with nurses having to ensure high standards of quality and handle complex situations effectively (5). In the workplace context, the concept of well-being has different meanings across organisations and countries. While there are many definitions of well-being, there are two main concepts, as measured by subjective and psychological well-being. There is no significant degree of differentiation between the definitions of the two concepts, with both sharing a similar conceptual structure (6). Subjective well-being is the subjective assessment of life satisfaction, and is a combination of the individual’s positive and negative moods and emotions (7). At the same time, some authors (7) have noted that subjective well-being is multidimensional, that it is subject to cultural differences, and that it has beneficial effects on health and social relationships. Psychological well-being is equated with positive human functioning and defined by six factors: accepting oneself, mastering the environment, positive relationships, personal growth, purpose in life, and autonomy. The psychological well-being model has been used to study relationships between well-being and personality traits, mental and physical health, healthy ageing, family and occupational experiences, and neurological processes (8). Well-being is one of the most important factors in whether nurses decide to remain in the profession (9), as well as on nurses’ engagement with work and on burnout beyond the effects of quantitative job demands and control (10). Employees are characterised as enjoying good well-being when they are satisfied with their work and organisation (11) and are more committed and affiliated (12). People with good well-being are more optimistic, more resilient to problems, and have a stronger belief in their ability to handle things (13). Some studies (14–16) have found that nurses’ psychological distress and well-being could impact on quality of care and patient safety. Life satisfaction is a general assessment of emotions and attitudes about an individual’s life at a certain point. It constitutes the judgement that a person makes about their life, and it is the most extensive construct for assessing subjective well-being (17). Greater life satisfaction is associated with organisational results, such as greater career satisfaction, organisational commitment and job satisfaction (18). Most definitions of job satisfaction tend to focus on how employees feel and think about their work. These definitions are very similar to those of life satisfaction, and involve emotional states, feelings, affective responses and cognitive evaluations of work (19). The basic condition for the successful management of employees in an organisation is reflected in support of high motivation and the satisfaction of employees at different ages (20). Research has shown that job satisfaction is associated with productivity (21), quality of patient care (22) and reduced staff turnover (23). Given the great importance of monitoring and ensuring employees’ well-being, which is associated with many positive outcomes for the individual (12, 13), for the organisation (9, 10) and for the patient (14–16), we decided that the study would aim to examine well-being and satisfaction among nurses in Slovenian hospitals and to identify the related demographic factors. While some studies carried out in various healthcare organisations have examined nurses’ job satisfaction, there has not yet been a study of the factors determining nurses’ psychological and subjective well-being in Slovenia. 2 METHODS 2.1 Study and Data Collection A descriptive cross-sectional study was used. All Slovenian public hospitals with internal medicine and surgical departments were invited to participate in the study (N=12). Eight hospitals confirmed participation. The study included a convenience sample: nurses who had completed secondary education or higher, and who worked at internal or surgical departments in eight Slovenian hospitals. According to the Health Statistical Yearbook (24), which is the Slovenian statistical yearbook for health, a total of 8,787 nurses work in Slovenian hospitals. According to information supplied by the management of the participating hospitals, 3,402 nurses were working at internal medicine and surgical departments. To ensure a representative sample that accurately reflected the characteristics of the study group, we decided to include 30% of all nurses from the participating hospitals. A total of 1,100 (32%) questionnaires were distributed: 85 were sent to mid- and unit-level head nurses and 1,015 were sent to other nursing staff. Questionnaires for head nurses were sent only to those who occupied a leading position in a department or unit, i.e. purposive sampling was used. A total of 1,100 hospital nurses received an invitation for participation, instructions, a guarantee of anonymity, and an envelope with a stamp and a return address (that of the researcher). The response rate was 58% (640), which represents 18.8% of the nurses working at the hospitals included in the study. 2.2 Measures The structured questionnaire included demographic questions (gender, level of education (secondary; high, university/master level); job position (leader, other employees)) and 115 questions related to job and life satisfaction, basic need satisfaction, and psychological and subjective well-being. Job satisfaction was determined by 15 items (25) and related to different dimensions of the work environment and the characteristics of work. Items were rated on a six-point Likert scale. The scale points were: 1 “completely unsatisfied”, 2 “unsatisfied”, 3 “slightly unsatisfied”, 4 “slightly satisfied”, 5 “satisfied” and 6 “completely satisfied”. The sum of the scores created an overall image of job satisfaction, with higher scores indicating a higher level of job satisfaction. The sum of whole scale ranged from 15 to 90. Cronbach’s alpha was 0.943. The satisfaction of participants’ basic needs was assessed using the Deci and Ryan Basic Need Satisfaction questionnaire (26). The questionnaire contains 21 items related to three dimensions of subjective well-being: competency (Cronbach’s a 0.942), autonomy (Cronbach’s a 0.963) and relatedness (Cronbach’s a 0.967). Items were rated on a six-point Likert scale. The scale points were: 1 “completely disagree”, 2 “disagree”, 3 “slightly disagree”, 4 “agree”, 5 “agree” and 6 “completely agree”. The sum of the scores created an overall image of a person’s experiences of the satisfaction of three needs (autonomy, competence, relatedness). Higher scores indicated higher levels of basic need satisfaction. The sum of the whole scale ranged from 21 to 126. Cronbach’s alpha was 0.984. Subjective well being was assessed using indicators of subjective well-being: the Positive Affect Negative Affect Schedule (PANAS) (27) and the Satisfaction with Life Scale (28). PANAS was designed to assess the affective dimension of subjective well-being, and consists of ten positive and ten negative moods in the past month. Items were rated on a six-point Likert scale. The scale points were: 1 “not at all/never”, 2 “slightly”, 3 “a little”, 4 “moderately”, 5 “quite a bit” and 6 “very much/extremely”. On the positive and negative mood scale, the scores ranged from 10 to 60, with higher scores representing a higher level of positive/negative affect. Cronbach’s alpha was 0.944 for positive affect and 0.646 for negative affect. Participants evaluated their satisfaction with life using the Satisfaction with Life Scale Five items were rated on a six-point Likert scale. The scale points were: 1 “completely disagree”, 2 “disagree”, 3 “slightly disagree”, 4 “slightly agree”, 5 “agree” and 6 “completely agree”. The sum of the scores created an overall image of life satisfaction, with higher scores indicating a higher level of life satisfaction. The sum of the whole scale ranged from 5 to 30. Cronbach’s alpha was 0.956. Subjective well-being is measured as a “sum of life satisfaction plus positive affect minus negative affect” (29). Higher scores indicated a higher level of subjective well-being. The sum of the whole scale ranged from 5 to 30. Psychological well-being was assessed using the Psychological Well-Being Scale (30). The questionnaire contains 54 items. Nine statements relate to each of the six dimensions of psychological well-being: accepting oneself (Cronbach’s a 0.978), positive relationships with others (Cronbach’s a 0.951), autonomy (Cronbach’s a 0.969), environmental management (Cronbach’s a 0.957), meaning of life (Cronbach’s 0.929) and personal growth (Cronbach’s 0.919). Items were rated on a six-point Likert scale. The scale points were: 1 “completely disagree”, 2 “disagree”, 3 “slightly disagree”, 4 “slightly agree”, 5 “agree” and 6 “completely agree”. The sum of the scores created an overall image of psychological well-being, with higher scores indicating a higher level of psychological well-being. The sum of the whole scale ranged from 54 to 324. Cronbach’s alpha was 0.991. For better understanding average values transformed the ratio variable into categorical. Six possible ratings were transformed into two categories. In the first category combined ratings 1, 2 and 3 related to dissatisfaction/disagreement, while into the second category combined 4, 5 and 6, which related to satisfaction/agreement. The Slovenian version of all the English-language questionnaires was developed using a translation–back-translation procedure. The English-language version was translated into Slovenian and then back-translated blindly into English by a Slovenian translator. The Slovenian translator then checked the equivalence of the English version of the instruments. The items of the Slovenian instrument were formulated with the same contents as the items in the original instrument. Four nurses and four head nurses held group conversations to verify whether the Slovenian version of the questionnaires was appropriate. They were asked to complete the instrument and to identify those items whose content was unclear. This check revealed a need for several items to be clarified. 2.3 Statistical Analysis Univariate and bivariate analyses were used. The partial and final scores were compared to the total score of each questionnaire. A Kolmogorov-Smirnov test confirmed the impression from a visual inspection that the scores for all studied variables was not normally distributed (p<0.001). Results were presented via the Median (Med) and interquartile range (IQR). Differences between individual variables were analysed using the Mann-Whitney and Kruskal-Wallis tests. A p-value of <0.05 was considered to be statistically significant. All the analyses were conducted using SPSS (Statistical Package for Social Sciences Program), version 24.0. 3 RESULTS A total of 640 nurses took part in the study: 346 (54%) from surgical departments and 294 (46%) from internal medicine departments. A total of 153 nurses (24%) were under 30, 410 (64%) were between 30 and 50, and 77 (12%) were over 50. The average age was 40.6 years. Forty nurses (7%) had less than 5 years’ experience in nursing, 134 (21%) had 5–10 years’ experience, 218 (33%) had 11-20 years’ experience, 128 (20%) had 21–30 years’ experience, and 120 (19%) had more than 31 years’ experience. Twenty-six per cent (163) had one or more chronic non­communicable diseases, 18% (110) were sometimes exposed to stress, 52% (334) were often exposed to stress, 30% (194) were always exposed to stress at the workplace, and 82% (525) self-assessed that they managed stress. Nurses’ assessed their job satisfaction (Med=45; IQR=36) and life satisfaction (Med=15; IQR=16) as moderate. Their psychological (Med=146; IQR=106) and subjective well­being (Med=18; IQR=14) was also moderate. 47% of nurses were satisfied with their job, 51% were satisfied with their life, 49% assessed their psychological well-being as good, and 47% assessed their subjective well-being as good. Table 1. Differences according to level of education. The percentage of those who were always exposed to stressful situations rose with level of education from 37.9% to 47.1%, as did job satisfaction (Med=40; IQR=36 to Med=49; IQR=34),life satisfaction (Med=15; IQR=16 to Med=16; IQR=14), basic need satisfaction (Med=61; IQR=67 to Med=83; IQR=53) psychological well-being (Med=130; IQR=108 to Med=197, IQR=88) and subjective well-being (Med=17; IQR=15 to Med=20; IQR12). Levels of exposure to stress (p<0.001), job satisfaction (p=0.031), psychological well-being (p=0.023) and subjective well-being (p=0.014) were found to differ significantly according to level of education (Table 1). The proportion of those who estimated that their work was always stressful increased in line with years of nursing service from 11.1% to 39.4%, while the proportion of those who managed stress fell from 85.5% to 76%. Life satisfaction (Med=24; IQR=13 to Med=11; IQR=15), job satisfaction (Med=54; IQR=18 to Med=41; IQR=40), psychological well­being (Med=211; IQR=44 to Med=121; IQR=92),subjective well-being (Med=25; IQR=18 to Med=13; IQR=16) and basic need satisfaction (Med=100; IQR=50 to Med=51; IQR=60) all decreased with years of service. Statistically significant differences in levels of exposure to stress (p=0.003), life satisfaction (p<0.001), job satisfaction (p=0.005), psychological well-being (p<0.001) and subjective well­being (p<0.001) were found in relation to years of service (Table 2). Exposure to stress (range from 1 to 4) Job satisfaction (range from 1 to 6) Life satisfaction (LS (range from 1 to 6) Psychological well-being (range from 1 to 6) Basic need satisfaction (range from 1 to 6) Subjective well-being (range from 1 to 6) 2.5(1) 40(36) 15(16) 130(108) 61(67) 17(15) 2.5(1) 40(36) 15(16) 130(108) 61(67) 17(15) 3.5(2) 49(34) 16(14) 197(88) 83(53) 20(12) 25.021 10.306 8.006 10.489 7.763 12.420 <0.001 0.031 0.091 0.023 0.092 0.014 Legend: Med – median; IQR – interquartile range; p – statistical significance Table 2. Differences in relation to years of service. Variables/years of service <5 6–10 11–20 21–30 >30 Kruskal­ p Med (IQR) Med (IQR) Med (IQR) Med (IQR) Med (IQR) Wallis H Exposure to stress 3(1) 3(1) 3(0) 3(1) 4(1) 16.763 0.003 Job satisfaction 54(18) 50(30) 48(36) 44(32) 41(40) 17.945 0.005 Life satisfaction 24(13) 22(14) 18(15) 15(14) 11(15) 28.492 <0.001 Psychological well-being 211(44) 196(108) 167(104) 134(173) 121(92) 28.536 <0.001 Basic need satisfaction 100(50) 90(61) 82(58) 63(58) 51(60) 23.994 <0.001 Subjective well-being 25(18) 22(14) 20(14) 16(13) 13(16) 30.663 <0.001 Legend: Med – median; IQR – interquartile range; p – statistical significance While women rated their life satisfaction (Med=15; IQR=16), job satisfaction (Med=45; IQR=36), basic need satisfaction (Med=68.5; IQR=60), psychological well­being (Med=146.5; IQR=108) and subjective well-being (Med=18; IQR=14) higher than men, the differences were not significant (Table 3). More women than men (32% vs. 27%) assessed that they were always exposed to stress, and 89% of men and 79% of women self-assessed that they managed stressful situations. Significant differences in terms of gender were only found in the management of managing stressful situations (Z=-1.955; p=0.048). Table 3. Differences according to gender. Head nurses assessed that their work was always stressful in 37.3% of cases (other nurses in 29.4% of cases), while of 84% of head nurses and 78% of other nurses assessed that they managed stressful situations. Head nurses rated their job satisfaction (Med=60; IQR=13), life satisfaction (Med=20; IQR=7), basic need satisfaction (Med=91; IQR=35), psychological well-being (Med=181; IQR=66) and subjective well-being (Med=22; IQR=5) higher than other nurses. Significant differences in relation to job position were identified only in job satisfaction (p<0.001) and subjective well-being (p=0.003) (Table 4). Variables/gender Female Male Mann- Z p Med (IQR) Med (IQR) Whitney U Exposure to stress 3(1) 3(1) 22975 0.598 0.550 Job satisfaction 45(36) 35(36) 22199 1.082 0.279 Life satisfaction 15(16) 13(16) 21683 1.307 0.191 Psychological well-being 146(108) 133(105) 19836 1.280 0.201 Basic need satisfaction 68.5(60) 57.5(64) 21141 0.777 0.437 Subjective well-being 18(14) 15.5(16) 20959 1.489 0.136 Legend: Med – median; IQR – interquartile range; p – statistical significance Table 4. Differences in relation to job position. Exposure to stress Job satisfaction Life satisfaction Psychological well-being Basic need satisfaction Subjective well-being 3(1) 40(35) 15(16) 137(114) 63(64) 16(15) 3(1) 60(13) 20(7) 181(66) 91(35) 22(5) 20193 11469.5 19028.5 16666.5 18733 15637 -0.676 -6.460 -1.190 -0.333 -0.614 -2.966 0.499 <0.001 0.234 0.739 0.539 0.003 Legend: Med – median; IQR – interquartile range; Z – test value; p – statistical significance Nurses with a chronic non-communicable disease assessed their work as stressful in 41% of cases (26% of cases for those without a chronic non-communicable disease). Nurses with a chronic non-communicable disease rated their satisfaction with life (Med=12; IQR=16), job satisfaction (Med=36; IQR=59), basic need satisfaction (Med=56; IQR=59), psychological well-being (Med=122.5; IQR=95) and subjective well-being (Med=14.5; IQR=15) lower than those without a non-communicable chronic disease. Significant differences between nurses with and without a chronic non-communicable disease were found in relation to exposure to stress (p=0.002), job satisfaction (p=0.029), life satisfaction (p=0.001), psychological well­being (p=0.049), basic need satisfaction (p=0.019) and subjective well being (p=0.003) (Table 5). Table 5. Differences in relation to presence of chronic disease. Variables/chronic disease Without With Mann- Z p Med (IQR) Med (IQR) Whitney U Exposure to stress 3(1) 3(1) 33230 -3.168 0.002 Job satisfaction 45.5(36) 36(59) 34795.5 -2.182 0.029 Life satisfaction 17.5(15) 12(16) 32395 -3.220 0.001 Psychological well-being 168(108) 122.5(95) 30728.5 -1.945 0.049 Basic need satisfaction 80(61) 56(59) 31634.5 -2.355 0.019 Subjective well-being 19.5(13) 14.5(15) 31610 -3.016 0.003 Legend: Med – median; IQR – interquartile range; Z – test value; p – statistical significance The proportion of employees who self-assessed that they were always exposed to stress and that they managed their stressful situations varied from hospital to hospital (between 9% and 53% and between 70 and 92% respectively). Again varying from hospital to hospital, nurses’ assessment of life satisfaction ranged from Med=11(IQR=8) to Med=25(IQR=5), assessment of subjective well-being between Med=13.5(IQR=16) to Med=25(IQR=4.7), assessment of job satisfaction between Med=30(IQR=23) to Med=64(IQR=10), assessment of basic need satisfaction between Med=50(IQR=37) to Med=112(IQR=6) and assessment of psychological well­being between Med=116(IQR=36) to Med=222(IQR=35). Significant differences were found between hospitals in relation to exposure to stress (p<0.001), job satisfaction (p<0.001), life satisfaction (p<0.001), psychological well­being (p<0.001), basic need satisfaction (p<0.001) and subjective well-being (p<0.001). 4 DISCUSSION The key finding of this study is that nurses in Slovenian hospitals are moderately satisfied with their work and life, and also display moderate levels of psychological and subjective well-being. While other studies (31, 32) have also found nurses’ psychological well-being to be moderate, Bourgault et al. (33) found low well-being among emergency nurses, as did Atanes et al. (34) among nurses at primary level and Oates et al. (35) among mental health nurses. In contrast to our results (Med=146; IQR=106), high well-being was identified (36) among mental health workers (285.6±41.7) and also non-health workers (269.7±44.07) in Australia. Female nurses experienced higher psychological and subjective well-being, which is comparable with study (37). As in other studies (38, 39), no statistically significant gender-related differences were found. Results showed that nurses were often (and some of them always) exposed to stress, which is in line with other studies (34, 40). Karimi et al. (41) noted that nurses’ predicted well-being was an important factor in stress-related presenteeism. Nurses with less than five years’ nursing experience had the highest levels of job and life satisfaction (self-assessed), as well as the highest psychological and subjective well­being, compared to nurses with more years of nursing experience. Nurses’ well-being decreased with years of service, which is in line with study (36). However, study (37) found that well-being increased with years of service. It was found that head nurses were more satisfied with their job than other nurses, and that job satisfaction decreased with years of service, which is in line with other studies (42, 43). Some studies (42-44) have also found that nurses have moderate levels of job satisfaction. Our findings regarding differences in well-being connected to job position and years of service accord with other studies (33, 34). Differences in job satisfaction, psychological and subjective well-being were found to be conditioned by level of education, i.e. nurses with a higher level of education were more satisfied with their job. This is in line with other studies (45, 46). Moreover, job satisfaction is positively associated with greater self-efficacy (47), engagement with work (48), occupational health (4) and job performance (21) on the part of nurses. There is also evidence of an association between nurses’ job satisfaction and patient satisfaction (48–50). In addition to stress, job satisfaction is also strongly associated with general health (4, 51, 52). Nurses who suffered from a chronic non-communicable disease rated their job satisfaction, life satisfaction, psychological well-being and subjective well-being lower than nurses who did not suffer from such diseases. Study (53) found that satisfaction with life and health was conditioned by the presence of chronic disease, with poor levels of life satisfaction being linked to undesirable health outcomes, including the elevated risk of chronic disease and death (54). Differences in the level of nurses’ satisfaction and well­ being from hospital to hospital can be explained by the results of other studies, which highlighted differences in organisational culture (55), organisational support (56) and leadership style (14). It is important for management to realise that well-being is of great importance not only to employees, as it promotes better health, positive self-esteem, better relationships with other people and resilience (7, 57), but also to the organisation (11, 12). Some studies (14-16) have found a significant relationship between nurses’ well-being and the quality of patient care -for example, Hall et al., in the systematic review contained in (58), found that 16 of the 27 studies established a significant correlation between poor well­ being and reduced patient safety. As they have a serious impact on work productivity, patient care, staff efficiency and turnover rates, the relationships between work-related stress, job satisfaction, well-being and the general health of nurses need to be better understood (4). Well-being is important for nurses, who face the challenge of balancing job stress and patient care outcomes without succumbing to emotional exhaustion. The results were presented to the management of each participating hospital in line with the interest they expressed, with the results from the specific hospital also being presented in relation to the overall results. With this, hospital management is able to identify the “real” situation and to try to recognise the importance of monitoring employees’ job satisfaction and well-being for better employee health and the achievement of better outcomes. The practical implications of the results suggest that interventions designed to promote positive well-being may help improve nursing environments, which in turn may result in improved approaches to safety and quality and improved nursing outcomes. Although these findings are notable, several limitations should be acknowledged. It is noteworthy that the study was cross-sectional rather than longitudinal. While the sample is not balanced in terms of nurses’ educational achievements and gender, this does reflect the actual structure of nursing in Slovenian hospitals. The researcher was not available during the research process in the participating hospitals, which meant that the respondents did not receive assistance if they did not understand an item and were not able to obtain additional explanations. It is possible that the respondents were overly positive or negative with regard to satisfaction and well-being. We therefore have to be careful when generalising the findings. Future research should examine longitudinally the possible interaction between well-being, the nursing practice environment and patient safety outcomes. 5 CONCLUSION The key finding of this study is that nurses in Slovenian hospitals are moderately satisfied with their work and life, and display moderate levels of psychological and subjective well-being, and that the differences are conditioned by level of education, years of service, the presence or otherwise of chronic disease and the organisation in which they work. In a constantly changing health system, hospital management have to recognise the importance of satisfied and healthy employees. Hospitals can be successful and achieve the goals of their organisations if employees are satisfied with their work and enjoy positive well-being. Management policies and practices that aim to implement changes to improve employees’ well-being need to be focused on enhancing nurses’ well-being so that nurses remain in the profession in greater numbers. Employers must monitor job satisfaction and take periodic steps to ensure well-being and health - indeed, this is the only way that organisations can adapt to the individual and achieve greater efficiency and better quality. Poor well-being associated with poorer patient safety has significant implications for policy-makers and management in healthcare settings. Healthcare organisations must provide a work environment that fosters nurses’ well­ being and safeguards against burnout, thus ensuring that patients are provided with a safe service. Positive Organisational Psychology suggests that employees’ health is an important goal in itself and one that management should include in its organisational policy. When establishing the level of job satisfaction, well-being and health, we must focus on how employees feel about their work and about personal relationships at the workplace, and on the way management has an impact on employees. CONFLICTS OF INTEREST The authors declare that no conflicts of interest exist. FUNDING The research received a non-specific grant from any funding agency in the public, commercial or not-for profit sectors. ETHICAL APPROVAL Research includes human data processed in accordance with the Declaration of Helsinki and approved by the National Medical Ethics Committee of the Republic of Slovenia (No 157/09/13). Before the interviews, the nature and the purpose of the study were explained and participants were informed that participation in the study was voluntary and anonymous. Participants gave their verbal consent before the study. The design of the study and the interviews with prior verbal consent were approved by the National Medical Ethics Committee of the Republic of Slovenia. REFERENCES 1. Leineweber C, Chungkham HS, Lindqvist R, Westerlund H, Runesdotter S, Smeds A, et al. Nurses’ practice environment and satisfaction with schedule flexibility is related to intention to leave due to dissatisfaction: a multi-country, multilevel study. Int J Nurs Stud. 2016;58:47-58. doi: 10.1016/j.ijnurstu.2016.02.003. 2. Baethge A, Müller A, Rigotti T. Nursing performance under high workload: a diary study on the moderating role of selection, optimization and compensation strategies. J Adv Nurs. 2016;72:545­ 57. doi: 10.1111/jan.12847. 3. Delgado C, Upton D, Ranse K, Furness T, Foster K. Nurses’ resilience and the emotional labour of nursing work: an integrative review of empirical literature. Int J Nurs Stud. 2017;70:71-88. doi: 10.1016/j. ijnurstu.2017.02.008. 4. Khamisa N, Oldenburg B, Peltzer K, Ilic D. Work related stress, burnout, job satisfaction and general health of nurses. Int J Environ Res Public Health. 2015;12:652-66. doi: 10.3390/ijerph120100652. 5. Ketchinger F, Kleinknecht-Dolf M, Spirig R, Frei IA, Huber E. Patient-related complexity of care: a challenge or overwhelming burden for nurses - a qualitative study. Scand J Caring Sci. 2018 Mar;32(1):204­ 212. doi: 10.1111/scs.12449. 6. Carlquist E, Ulleberg P. Delle Fave A, Nafstad HE, Blakar RM. Everyday understandings of happiness, good life, and satisfaction: three different facets of well-being. Appl Res Qual Life. 2017;12:481-505. doi:10.1007/s11482-016-9472-9. 7. Diener E, Heintzelman SJ, Kushlev K, Tay L, Wirtz D, Lutes LD, et al. Findings all psychologists should know from the new science on subjective well-being. Can Psycho. 2017;58(2):87-104. doi: 10.1037/ cap0000063. 8. Ryff CD. Eudaimonic well-being, inequality, and health: recent findings and future directions. Int Rev Econ. 2017;64:159–78. doi: 10.1007/ s12232-017-0277-4. 9. Holland P, Tham TL, Sheehan C, Cooper B. The impact of perceived workload on nurse satisfaction with work-life balance and intention to leave the occupation. Appl Nurs Res. 2019;49:70-6. doi: org/10.1016/j. apnr.2019.06.001. 10. Santos A, Chambel MJ, Castanheira F. Wellbeing among hospital nurses: a cross-sectional study of the contributions of relational job characteristics. Int J Nurs Stud. 2020;105:103438. doi: 10.1016/j. ijnurstu.2019.103438. 11. McGonagle AK, Fisher GG, Barnes-Farrell JL, Grosch JW. Individual and work factors related to perceived work ability and labor force outcomes. J Appl Psychol. 2016;100:376-98. doi: 10.1037/a0037974. 12. Battistelli A, Galletta M, Vanderberghe C, Odoardi C. Perceived organisational support, organisational commitment and self-competence among nurses: a study in two Italian hospitals. J Nurs Manag. 2016;24:44–53. doi: 10.1111/jonm.12287. 13. Mayordomo T, Viguer P, Sales A, Satorres E, Melendez JC. Resilience and coping as predictors of well-being in adults, 2016. J Psychol. 2016;2150(7):809-21. doi: 10.1080/00223980.2016.1203276. 14. Boamah SA, Spence Laschinger HK, Wong C, Clarke S. Effect of transformational leadership on job satisfaction and patient safety outcomes. Nurs Outlook. 2018;66:180-9. doi: 10.1016/j. outlook.2017.10.004. 15. Hall LH, Johnson J, Watt I, Tsipa A, O’Connor DB. Healthcare staff wellbeing, burnout, and patient safety: a systematic review. Plos One. 2016;11:e0159015. doi: 10.1371/journal.pone.0159015. 16. Welp A, Manser T. Integrating teamwork, clinician occupational well­being and patient safety – development of a conceptual framework based on a systematic review. BMC Health Serv Res. 2016;16:281. doi: 10.1186/s12913-016-1535-y. 17. Hamarta E, OzyesilZ, Deniz M, Dilmac B. The prediction level of mindfulness and locus of control on subjective well-being. Int J Acad Res. Part B; 2013;5(2):145-50. doi: 10.7813/2075-4124.2013/5-2/B.22. 18. Chughtai AA. A closer look at the relationship between life satisfaction and job performance. Appl Res Qual Life. 2019. doi: 10.1007/s11482­019-09793-2. 19. Unanue W, Gomez ME, Cortez D, Oyanedel JC, Mendiburo-Seguel A. Revisiting the link between job satisfaction and life satisfaction: the role of basic psychological needs. Front Psychol. 2017;9(8):680. doi: 10.3389/fpsyg.2017.00680. 20. Rožman M, Treven S, Cancer V. Motivation and satisfaction of employees in the workplace. Bus System Res. 2017;8:14-25. doi: 10.1515/bsrj-2017-0013. 21. Platis C, Reklitis P, Zimers S. Relation between job satisfaction and job performance in healthcare services. Procedia Soc Behav Sci. 2015;175:480-7. doi: 10.1016/j.sbspro.2015.01.1226. 22. Koy V, Yunibhand J, Angsuroch Y, Fisher M. Relationship between nursing care quality, nurse staffing, nurse job satisfaction, nurse practice environment, and burnout: literature review. J Res Med Sci. 2015;3:1825-31. doi: 10.18203/2320-6012.ijrms20150288. 23. Lu L, Lu a, Gursoy D, Neale N. Work engagement, job satisfaction, and turnover intentions: A comparison between supervisors and line-level employees. Int J Contemp Hosp Manag. 2016;28(4):737-91. doi: 10.1108/IJCHM-07-2014-0360. 24. Zdravstveni statisticni letopis. Viri v zdravstvu (kadrovski, organizacijski in drugi viri). 2017. Accssed September 21, 2019 at: http://www.nijz.si/sites/www.nijz.si/files/uploaded/publikacije/ letopisi/2017/8_viri_v_zdravstvu_2017.pdf, Slovenia. 25. Mihalic R. Povecajmo zadovoljstvo in pripadnost zaposlenih. Škofja Loka: Mihalic & Partner, 2008. Slovenian. 26. Deci EL, Ryan RM. The ‘‘what” and ‘‘why” of goal pursuits: human needs and the self determination of behavior. Psychol Inq. 2000;11:227–68. doi: 10.1207/S15327965PLI1104_01. 27. Watson D, Clark LA, Tellegen A. Development and validation of brief measures of positive and negative affect: the PANAS scales. J Pers Soc Psychol. 1988;54:1063–70. doi: 10.1037//0022-3514.54.6.1063. 28. Diener E, Emmons R, Larsen RJ, Griffin S. The satisfaction with life scale. J Pers Assess. 1985;49:71–5. doi: 10.1207/s15327752jpa4901_13. 29. Linley PA, Joseph S. Applied positive psychology: a new perspective for professional practice. In: Positive psychology in practice. John Wiley & Sons Inc. 2004. Accessed September 29, 2019 at: https:// onlinelibrary.wiley.com/doi/10.1002/9780470939338.ch1. 30. Ryff CD; Keyes CL. The structure of psychological well-being revised. J Pers Soc Psychol. 1995;69:712-27. 31. Blumerga S, Olava S. Quality of hospital nursing work life, psychological and subjective well-being. 2016. Accessed August 27th, 2019 at: https://llufb.llu.lv/conference/REEP/2016/Latvia-Univ-Agricult-REEP­2016proceed2255-808X-295-300.pdf. 32. Meng R, Luo Y, Liu B, Hu Y, Yu H. The nurses’ well-being index and factors influencing this index among nurses in central china: a cross-sectional study. PLoS One. 2015;10:e0144414. doi:10.1371/journal. pone.0144414. 33. Bourgault P, Lavoie S, Paul-Savoie E, Grégoire M, Michaud C, Gosselin E et al. Relationship between empathy and well-being among emergency nurses. J Emerg Nurs. 2015;41:323-8. doi: 10.1016/j.jen.2014.10.001. 34. Atanes ACM, Andreoni S, Hirayama MS, Montero-Marin J, Barros VV, Ronzani TM et al. Mindfulness, perceived stress, and subjective well­being: a correlational study in primary care health professionals. BMC Complement Altern Med. 2015;2:303 doi: 10.1186/s12906-015-0823-0. 35. Oates J, Jones J, Drey N. Subjective well-being of mental health nurses in the United Kingdom: Results of an online survey. Int J Ment Health Nurs. 2017;26:391-401. doi: 10.1111/inm.12263. 36. Koller SL, Hicks RE. Psychological capital qualities and psychological well-being in Australian mental health professional. Int J Psychol Stud. 2016;8:41-53. doi: 10.5539/ijps.v8n2p41. 37. Van der Heijden BIJM, Mulder RH, König C, Anselmann V. Toward a mediation model or nurses’ well-being and psychological distress effects of quality of leadership and social support at work. Medicine. 2017;96:e6505. doi: 10.1097/MD.0000000000006505. 38. De Dio S, Cedrone F, Snita D, Ricci P, Corbosiero P, Di Tragia M et al. Quality of life in workers and stress: gender differences in exposure to psychosocial risks and perceived well-being. Biomed Res Int. 2017;2017:7340781. doi: 10.1155/2017/7340781. 39. Balzarotti S, Biassoni F, Villani D, Punas A, Velotti P. Individual differences in cognitive emotion regulation: implications for subjective and psychological well-being. J Happiness Stud. 2016;17(1): 125–43. doi: 10.1007/s10902-014-9587-3. 40. Dobnik M, Maletic M, Skela-Savic B. Work-related stress factors in nurses at Slovenian hospitals – a cross-sectional study. Zdr Varst. 2018;57:192-200. doi: 10.2478/sjph-2018-0024. 41. Karimi L, Cheng C, Bartram T, Leggat SG, Sarheshik S. The effects of emotional intelligence and stress-related presenteeism on nurses’ well-being. Asia Pac J Hum Res. 2015;53:296-310. doi: 10.1111/1744­7941.1204. 42. Chien WT, Yick SY. An Investigation of Nurses’ Job Satisfaction in a Private Hospital and Its Correlates. Open Nurs J. 2016: 10: 99–112. doi: 10.2174/1874434601610010099. 43. Lorber M, Skela-Savic B. Job satisfaction of nurses in Slovenian hospitals. Croat Med J. 2012;53:263-70. doi: 10.3325/cmj.2012.53.263. 44. Labrague LJ, LcEnroe-Petite, Gloe D, Tsaras D, Arteche DL, Maldia F. Organizational politics, nurses’ stress, burnout levels, turnover intention and job satisfaction. Int Nurs Rev. 2017;64(1):109-16. doi: 10.1111/inr.12347. 45. Rosta J, Aasland OG, Nylenna M. Changes in job satisfaction among doctors in Norway from 2010 to 2017: a study based on repeated surveys. BMJ Open. 2019;8,9:e027891. doi: 10.1136/bmjopen-2018-027891. 46. Lee Y, Sabharwal M. Education – job match, salary, and job satisfaction across the public, non-profit, and for profit sectors: survey of recent college graduates. Pub Manag Revi. 2015;18:40-64. doi: 10.1080/14719037.2014.957342. 47. Allan BK, Dexter C, Kinsley R, Parker S. Meaningful work and mental health: job satisfaction as a moderator. J Ment Health. 2017;27:38-66. doi: 10.1080/09638237.2016.1244718. 48. De Simone S, Planta A, Cicotto G. The role of job satisfaction, work engagement, self efficacy and agentic capacities on nurses’ turnover intention and patient satisfaction. Appl Nurs Res. 2018;39:130-40. doi: 10.1016/j.apnr.2017.11.004. 49. García-Sierra R, Fernández-Castro J, Martínez-Zaragoza F. Relationship between job demand and burnout in nurses: does it depend on work engagement. J Nurs Manag. 2016;24:780-8. doi: 10.1111/jonm.12382. 50. Lu H, Zhao Y, While A. Job satisfaction among hospital nurses: A literature review. Int J Nurs Stud. 2019;94:21-31. doi: 10.1016/j. ijnurstu.2019.01.011. 51. Masum AK, Azad MA, Hoque KE, Beh LS, Wanke P, Arslan O. Job satisfaction and intention to quit: an empirical analysis of nurses in Turkey. PeerJ. 2016;26:e1896. doi: 10.7717/peerj.1896. 52. Khamisa N, Peltzer K, Ilic D., Oldenburg, B. Work related stress, burnout, job satisfaction and general health of nurses: a follow-up study. Int J Nurs Prac. 2016;22:538-45. doi: 10.1111/ijn.12455. 53. Karyani AK, Matin BK, Gebru AA, Dizai JY, Rezaei S. Life and health satisfaction and their association toward health-related quality of life, body mass index and chronic diseases in Iran. J Educ Health Promot. 2019;8: 1. doi: 10.4103/jehp.jehp_204_18. 54. Rosella LC, Fu L, Buajati E, Goel V. Death and chronic disease risk associated with poor life satisfaction: a population-based cohort study. Am J Epidemiol. 2019:188(2):323–31. doi: 10.1093/aje/kwy245. 55. Körner M, Wirtz, MA, Bengel J, Göritz AS. Relationship of organizational culture, teamwork and job satisfaction in interprofessional teams. BMC Health Serv Res. 2015;15:243. doi: 10.1186/s12913-015-0888-y. 56. Chang CS. Moderating effects of nurses’ organizational support on the relationship between job satisfaction and organizational commitment. West J Nurs Res. 2015;37:724-45. doi: 10.1177/0193945914530047. 57. Gardner D. The importance of being resilient: psychological well­being, job autonomy, and self-esteem of organization managers. Pers Individ Dif. 2020; 155(1):109731. doi: 10.1016/j.paid.2019.109731. 58. Hall LH, Johnson J. Watt I, Tsipa A, O’Connor DB. Healthcare staff wellbeing, burnout, and patient safety: a systematic review. PLoS One. 2016; 11(7): e0159015. doi: 10.1371/journal.pone.0159015. CROSSWALK EQ-5D-5L VALUE SET FOR SLOVENIA PREHODNI EQ-5D-5L VREDNOSTNI SET ZA SLOVENIJO Received: Apr 4, 2020 Accepted: Jun 9, 2020 ABSTRACT Keywords: EuroQol, EQ-5D-5L, interim value set, health-related quality of life, patient- reported outcomes IZVLECEK Kljucne besede: EuroQol, EQ­5D-5L, prehodni vrednostni set, z zdravjem povezana kakovost življenja, izhodi porocani s strani pacientov Valentina PREVOLNIK RUPEL1*, Marko OGOREVC1 1Institute for Economic Research, Kardeljeva plošcad 17, 1000 Ljubljana, Slovenia Original scientific article Introduction: Due to the availability of the EQ-5D-5L instrument official translation into Slovenian its use is widespread in Slovenia. However, the health profiles obtained in many studies cannot be ascribed their appropriate values as the EQ-5D-5L value set does not yet exist in Slovenia. Our aim was to estimate an interim EQ-5D-5L value set for Slovenia using the crosswalk methodology developed by the EuroQol Group on the basis of the EQ-5D-3L Slovenian TTO value set. Our secondary aim was to compare the interim values obtained with the EQ-5D-3L Slovenian values. Methods: To obtain a Slovenian interim EQ-5D-5L value set, we applied the crosswalk methodology developed by the EuroQol Group to the Slovenian EQ-5D-3L TTO value set. We examined the differences between values by comparing the mean 3L and 5L value scores and the distribution of values across all respondents. Results: By definition, 3-level and 5-level versions have the same range (from 1 to -0.495) and a health state coded 22222 in the 3-level version corresponds to 33333 in the 5- level version. While the addition of a “slight” severity level (22222) in the 5-level version has a low informational value, the addition of a “severe” health state (44444) covers larger range of the scale. The 5-level version results in fewer health states being valued below 0 and above 0.8. Conclusion: The EQ-5D-5L value set, based on the crosswalk methodology, should be used until a value set for the EQ-5D-5L is derived from preferences elicited directly from a representative sample of the Slovenian general population. Uvod: Uporaba instrumenta EQ-5D-5L je v Sloveniji že zelo razširjena zaradi razpoložljivosti uradnega prevoda instrumenta v slovenski jezik. Žal zdravstvenim profilom raziskovane populacije, pridobljenim v številnih raziskavah, ni mogoce pripisati njihovih vrednosti, saj v Sloveniji še nimamo izracunanih vrednosti EQ-5D-5L zdravstvenih stanj. Naš cilj je bil oceniti vrednosti zdravstvenih stanj EQ-5D-5L za Slovenijo z metodo mapiranja, ki jo je razvila skupina EuroQol. Za osnovo smo uporabili slovenske vrednosti zdravstvenih stanj EQ-5D-3L. Naš sekundarni cilj je bil primerjati pridobljene 5L vrednosti s slovenskimi vrednostmi EQ-5D-3L. Metode: Za pridobitev slovenskega nabora vrednosti EQ-5D-5L smo uporabili metodologijo mapiranja, ki jo je razvila skupina EuroQol, preracunali pa smo jo iz vrednosti EQ-5D-3L TTO. Razlike med vrednostmi smo preucili s primerjavo povprecnih vrednosti 3L in 5L in porazdelitvijo vrednosti med vsemi anketiranci. Rezultati: Po definiciji imata seta vrednosti za 3 in 5 ravni (EQ-5D-3L in EQ-5D-5L) enak razpon vrednosti (od 1 do ­0,495), zdravstveno stanje 22222 v 3-stopenjski razlicici pa ustreza stanju 33333 v 5-stopenjski razlicici. Medtem ko ima dodatek “manjše” stopnje težavnosti oz. kodiranega stanja 22222 v 5-stopenjski razlicici majhno informacijsko vrednost, je dodana vrednost “hude” stopnje težavnosti oz. zdravstvenega stanja kodiranega kot 44444 vecja in zajema vecji obseg lestvice. 5- stopenjski set vrednosti rezultira v manj zdravstvenih stanjih, ki so ocenjene pod 0 in nad 0,8. Zakljucek: Nabor vrednosti EQ-5D-5L, ki je pridobljen z mapiranjem, lahko raziskovalci v Sloveniji uporabljajo vse dokler ne bodo na razpolago vrednosti stanja EQ-5D-5L, pridobljene neposredno iz preferenc reprezentativnega vzorca slovenske splošne populacije do zdravstvenih stanj. *Corresponding author: Tel. + 386 1 478 68 70; E-mail: katka.rupel@gmail.com © National Institute of Public Health, Slovenia. 1 INTRODUCTION The EuroQol instrument (EQ-5D) is the most commonly used preference-based quality-of-life measure deriving health state utilities for use in cost-utility analyses (1, 2). In Slovenian health technology assessment (HTA) there is no preference expressed for a specific instrument (3); however, cost-utility is an analysis often used in HTAs. The EQ-5D five-level version (EQ-5D-5L) was developed by the EuroQol organization in 2009 (4) to avoid the methodological limitations (5) of the three-level version, and has by now been tested in different samples, showing strong psychometric properties. The new instrument seems to reduce the ceiling effect, improve discriminatory power and establish convergent and known-group validity in comparison to the three-level questionnaire (6-9). EQ-5D is a generic instrument and can be used in economic as well as population studies, measuring health-related quality of life. One of the advantages prompting its widespread use is country-specific value sets. These are usually obtained from the general population, although recent studies are engaged in elicitation of preferences from patients and other population subgroups, such as adolescents (10, 11). Before 2009, three-level value sets were developed and used across countries. With the arrival of EQ-5D-5L, value sets based on preferences directly elicited from representative general population samples began to develop. The data collection for the first two sets in England and Canada started as early as 2012 (12, 13), although the first value sets were only published in 2016 (13-17). Currently, there are 20 value sets published, the most recent ones being from Vietnam and Hungary (18, 19). Slovenia is one of the countries with an official translation of the EQ-5D-5L questionnaire, but without supporting values for each of the 3,125 health states. While the five-level instrument is already used in many studies measuring the health status of different population subgroups, those health states cannot be ascribed their values. The EQ-5D­3L value set for Slovenia was published in 2020 (20). In the meantime, an interim scoring method for the EQ­5D-5L was published that allows EQ-5D-5L values to be derived from any existing EQ-5D-3L value set (21). Interim values are available for many countries (Denmark, France, Germany, Japan, the Netherlands, Spain, Thailand, the United Kingdom, the United States, and Zimbabwe), although Poland is the only Central European country with an interim EQ-5D-5L value set (22). The National Institute for Health and Care Excellence (NICE) recommends the use of the crosswalk value set in HTA (21). In the present study, our aim was to estimate an interim EQ-5D-5L value set for Slovenia using the crosswalk methodology developed by the EuroQol Group and to compare values obtained using the EQ-5D-5L crosswalk with those based on the EQ-5D-3L and EQ-5D-5L values from other countries’ interim sets. 2 METHODS 2.1 Questionnaire The EQ-5D is a standardized measure of health status developed by the EuroQol Group to provide a simple, generic measure of health for clinical and economic analyses and population health surveys (24). Both three- and five-level versions consist of two measures: the EQ-5D descriptive system and the EQ visual analogue scale (EQ VAS). The EQ-5D-5L descriptive system comprises the same five dimensions as the EQ-5D-3L (mobility, self-care, usual activities, pain/discomfort, and anxiety/depression), but with five levels of severity (no problems, slight problems, moderate problems, severe problems, and extreme problems/unable to) compared to three levels of severity (no problems, some problems, and extreme problems/ unable to/confined to bed) in the EQ-5D-3L. For each dimension, the patient chooses a level, and a five-digit patient profile is thus obtained, such as 12543 (patient has no problems with mobility, has slight problems with taking care of self, has extreme problems with usual activities, suffers from severe pain or discomfort, and has moderate problems with anxiety/depression). EQ-5D health states, defined by the EQ-5D descriptive system, may be converted into a single summary index by applying a formula that essentially attaches values to each of the levels in each dimension. There are 3,125 (35) possible patient profiles in the EQ-5D-5L definition of health states, and each health state has its own value. 2.2 Crosswalk Study The objective of the Crosswalk study (21) was to develop values sets for the EQ-5D-5L by mapping to the currently available EQ-5D-3L value sets. The study included 3,691 respondents from six European countries (Denmark, England, Italy, the Netherlands, Poland, and Scotland). Participants had a range of different conditions and different levels of severity of reported problems. They completed both the EQ-5D-3L and EQ-5D-5L descriptive systems at the same time. For each health state described by the EQ-5D-5L system, the probability of reporting each of the 243 EQ-5D-3L health states was estimated. This resulted in a large, 3,125×243 matrix of transition probabilities. The EQ-5D-5L index value is calculated by multiplying the 243 transition probabilities by their corresponding EQ-5D-3L index values, and subsequently summing them up. 10.2478/sjph-2020-0024 2.3 Slovenian EQ-5D-3L Value Set The Slovenian EQ-5D-3L valuation study used the modified Measurement and Value of Health protocol (from the Measurement and Value of Health study) (25). In the study conducted in 2006, 225 individuals valued 15 health states out of total of 23 included in the research. Modelling resulted in a final choice of a six-parameter constrained regression model with a supplementary power term for both visual analogue scale (VAS) and time trade-off (TTO) based value sets. A power term below 1 indicates that respondents show substantially diminishing sensitivity to increasing health problems (20). The Slovenian TTO value set has the lowest value of -0.495 for health state 33333, and 82 health states (33.7%) are valued lower than zero. The most important health dimension is mobility, followed by pain/discomfort. Self-care, anxiety/depression and usual activities are seen as less important. Figure 1. Relative importance of health dimensions. Comparisons with the Polish and UK TTO values show considerable differences, mostly due to mobility having a substantially greater weight in Slovenia. The UK value set generally produces lower values for mild states, while the Polish value set produces higher ones (26). International comparisons show that Polish values differ considerably from those elicited in Western European countries (26). To obtain a Slovenian interim EQ-5D-5L value set, we applied the crosswalk methodology developed by the EuroQol Group (21) to the Slovenian EQ-5D-3L TTO-based value set (20). We examined the differences between values obtained by comparing the mean 3L and 5L value scores and the distribution of values across all respondents. We also estimated the proportion of states with values less than zero. The statistical analysis was conducted using R (27), charting was done using the ggplot2 package (28) and basic data manipulation with the dplyr package (29). Zdr Varst. 2020;59(3):189-194 3 RESULTS The estimated Slovenian values for 3,125 EQ-5D-5L health state are shown in Figure 1, while the values for some selected health states are presented in Table 1. The whole value set can be obtained from the authors. Table 1. Selected health states, 3L and 5L values. EQ-5D-3L EQ-D5-5L Utility 11111 11111 1.000 . 11211 0.894 . 11112 0.885 . 12111 0.879 . 11121 0.836 . 21111 0.747 . 11222 0.741 . 12221 0.738 . 22211 0.666 . 22222 0.580 . 23332 0.555 . 22333 0.554 . 33322 0.543 22222 33333 0.524 . 44433 0.392 . 34443 0.315 . 33444 0.277 . 44444 0.208 . 44555 -0.075 . 45554 -0.102 . 55544 -0.351 33333 55555 -0.495 Source: Authors’ own calculations. By definition of the crosswalk methodology both versions, three-level and five-level, have the same range (from 1 to -0.495) and the health state coded 22222 in the three-level version corresponds to 33333 in the five-level version. The five-level version has a lower mean and median and is less skewed. The addition of a “slight” severity level in the five-level version has low informational value. The difference between a “slight” health state (a health state where all health dimensions are at the “slight” level, coded: 22222) and “middle” health state (33333) is 0.056, which corresponds to 3.7% of the total range (a range between perfect health, namely 11111, and the worst health state, 55555). The addition of the “slight” level results in proportionally less “good” health states (0.5% of health states with a value higher than 0.8), when compared to the three-level version (1.6% of health states with a value higher than 0.8). Table 2. Comparison of the Slovenian EQ-5D-3L and Slovenian EQ-5D-5L crosswalk value sets. Parameter Slovenian EQ-5D-3L Crosswalk value set Slovenian EQ-5D-5L value set Number of health states 243 3125 Range -0.495 to 1 -0.495 to 1 Mean±SD 0.18±0.324 0.258±0.27 Median 0.190 0.304 Skewness 0.070 -0.419 Kurtosis 2.170 2.450 States worse than dead (index <0), n (%) 82 (33.745%) 653 (20.896%) States with index >0.8, n (%) 4 (1.646%) 16 (0.512%) Figure 2. Distribution of values for EQ-5D-3L and EQ-5D-5L versions and transition matrix. On the other hand, the addition of an extra level in the lower part of the scale, the “severe” health state (coded: 44444), has greater informational value. The difference between the “middle” health state (33333) and “severe” health state (44444) is 0.208, which corresponds to 21.1% of the total range. The difference between the “severe” health state (44444) and PITS health state (55555) is 0.703, or 47% of the total range. Moreover, the addition of the “severe” level results in proportionally fewer health states with values below zero (20.9% of health states) for the five-level version when compared to the three-level version (33.7% of health states with values lower than zero). Figure 3. Density of utility scores. We found that the Slovenian interim EQ-5D-5L value set generated values that are narrower and more densely distributed around the median than those generated by the EQ-5D-3L value set. A higher density can be observed in other countries as well, such as Denmark, France, Germany, the United Kingdom, Poland, the Netherlands, and Spain (22, 23). It appears that these characteristics are related to the crosswalk methodology, but this issue remains unresolved at the moment. 10.2478/sjph-2020-0024 4 DISCUSSION The Slovenian crosswalk or interim value set derived in this study is created following the EuroQol Group crosswalk methodology as a temporary solution for use until the Slovenian EQ-5D-5L value set, based on directly elicited preferences from the general population, is available. As the number of studies using the EQ-5D-5L instrument is increasing and the corresponding value set is not yet available, the presentation of these values will enable researchers to ascribe the related values to the health states of the population under study. In Central and Eastern Europe there are currently eight EQ­5D value sets available: VAS- and TTO-based 3L value sets (20) from Slovenia alongside the crosswalk set published in this study; three value sets from Poland, 3L TTO (30), 5L TTO (31) and crosswalk (22) value set; and 3L and 5L value sets from Hungary (19). In the article we did not present all of the 3,125 health state values, but just a few selected ones that can be used in population, economic or clinical studies until the directly elicited population-based EQ-5D-5L value set is available in Slovenia. Due to the restrictions on the range of the scale (22), relatively fewer health states are valued below zero and above 0.8. At the same time, relatively more health states are valued as moderate (0.4-0.8). It would be interesting to study whether the same phenomena are observed in the directly elicited EQ-5D-5L value set. The strength of the study is the use of the official crosswalk methodology provided by the EuroQol organization, although the fact is that the analyses to obtain the matrix for mapping the EQ-5D-5L to EQ-5D-3L value sets were run on an international sample of respondents that did not include Slovenians (21). Furthermore, the values, which can be obtained in full from the authors, will be of use to researchers and users of EQ-5D-5L until the directly elicited value set is available. The limitation of the mapping is certainly the dependency of the data between both datasets, as well as some assumptions which are part of the methodology – imposing them leads to various errors that are not present in directly elicited value sets. 5 CONCLUSIONS In the study we estimated the EQ-5D-5L value set for Slovenia, based on the crosswalk methodology. The values obtained can be applied by researchers to health states obtained in various types of studies in the Slovenian context. The values should be used until a value set for the EQ-5D-5L is derived from preferences elicited directly from a representative sample of the Slovenian general population. The users of the EQ-5D-5L are thus able to use the updated EQ-5D instrument, which is claimed to have Zdr Varst. 2020;59(3):189-194 improved properties in comparison to the same instrument with three levels of problems for all dimensions. CONFLICT OF INTEREST VPR is a member of EuroQol Group. MO has no conflict of interest. FUNDING This research was also supported by the Slovenian Research Agency (Grant No. P5-0096). ETHICAL APPROVAL Not required as only secondary data are used in this study. REFERENCES 1. Devlin N, Brooks R. EQ-5D and the EuroQol group: past, present, future. Appl Health Econ Health Policy. 2017;15(2):127-37.doi: 10.1007/ s40258-017-0310-5. 2. Richardson J, McKie J, Bariola E. Multiattribute utility instruments and their use. In: Culyer AJ, editor. Encyclopedia of health economics. San Diego: Elsevier, 2014:341-57. 3. Rules on inclusion of medicines on the list. Official Gazette 35/13. Accessed Apr 2020 at: https://www.uradni-list.si/glasilo-uradni-list­rs/vsebina/2013-01-1323?sop=2013-01-1323. 4. Herdman M, Gudex C, Lloyd A, Janssen M, Kind P, Parkin D, et al. Development and preliminary testing of the new five-level version of EQ-5D (EQ-5D-5L). Qual Life Res. 2011;20:1727-36. doi: 10.1007/s11136­011-9903-x. 5. Marra CA, Woolcott JC, Kopec JA, Shojania K, Offer R, Brazier JE, et al. A comparison of generic, indirect utility measures (the HUI2, HUI3, SF­6D, and the EQ-5D) and disease-specific instruments (the RAQoL and the HAQ) in rheumatoid arthritis. Soc Sci Med. 1982;2005(60):1571-82. doi: 10.1016/j.socscimed.2004.08.034. 6. Sakthong P, Sonsa-Ardjit N, Sukarnjanaset P. Munpan W. Psychometric properties of the EQ-5D-5L in Thai patients with chronic diseases. Qual Life Res. 2015;24:3015-22. doi: 10.1007/s11136-015-1038-z. 7. Kim TH, Jo MW, Lee SI, Kim SH, Chung SM. Psychometric properties of the EQ-5D-5L in the general population of South Korea. Qual Life Res. 2013;22:2245-53. doi: 10.1007/s11136-012-0331-3. 8. Buchholz I, Janssen MF, Kohlmann T, Feng YS. A systematic review of studies comparing the measurement properties of the three-level and five-level versions of the EQ-5D. Pharmacoeconomics. 2018;36(6):645­ 61. doi: 10.1007/s40273-018-0642-5. 9. Rencz F, Lakatos PL,Gulácsi L, Brodszky V, Kürti Z,Lovas S, et al. Validity of the EQ-5D-5L and EQ-5D-3L in patients with Crohn’s disease. Qual Life Res. 2019;28(1):141-52. doi: 10.1007/s11136-018-2003-4. Epub 2018 Sep 17. 10. Ogorevc M, Murovec N, Fernandez NB, Prevolnik Rupel V. Questioning the differences between general public vs. patient based preferences towards EQ-5D-5L defined hypothetical health states. Health Policy. 2019;123(2):166-72. doi: 10.1016/j.healthpol.2017.03.011. 11. Peeters Y, Stiggelbout AM. Health state valuations of patients and the general public analytically compared: a meta-analytical comparison of patient and population health state utilities. Value Health. 2010;13:306-9. doi: 10.1111/j.1524-4733.2009.00610.x. 12. Devlin N, Shah K, Feng Y, Mulhern B, van Hout B. Valuing health-related quality of Life: an EQ-5D-5L value set for England. Health Econ. 2017;1­ 16. doi: 10.1002/hec.3564. 13. Xie F, Pullenayegum E, Gaebel K, Bansback N, Bryan S, Ohinmaa A, et al. A time trade-off-derived value set of the EQ-5D-5L for Canada. Med Care. 2016;54(1):98-105. doi: 10.1097/MLR.0000000000000447. 14. Shiroiwa T, Ikeda S, Noto S, Igarashi A, Fukuda T, Saito S,et al. Comparison of value set based on DCE and/or TTO data: scoring for EQ-5D-5L health states in Japan. Value Health. 2016;19(5):648-54. doi: 10.1016/j.jval.2016.03.1834. 15. Kim SH, Ahn J, Ock M, Shin S, Park J, Luo N, et al. The EQ-5D-5L valuation study in Korea. Qual Life Res. 2016;25(7):1845-52. doi: 10.1007/s11136-015-1205-2. 16. Versteegh MM, Vermeulen KM, Evers SM, de Wit GA, Prenger R, Stolk EA. Dutch tariff for the five-level version of EQ-5D. Value Health. 2016;19(4):343-52. doi: 10.1016/j.jval.2016.01.003. 17. Augustovski F, Rey-Ares L, Irazola V, Garay OU, Gianneo O, Fernandez G, et al. An EQ-5D-5L value set based on Uruguayan population preferences. Qual Life Res. 2016;25(2):323-33. Erratum in: Qual Life Res. 2016;25(2):335. doi: 10.1007/s11136-015-1086-4. 18. Mai VQ, Sun S, Minh HV, Luo N, Giang KB, Lindholm L, et al. An EQ­5D-5L value set for Vietnam. Qual Life Res. 2020. doi: 10.1007/s11136­020-02469-7. [AOP]. 19. Rencz F, Brodszky V, Gulacsi L, Golicki D, Ruzsa G, Pickard AS, et al. Parallel valuation of the EQ-5D-3L and EQ-5D-5Lby time trade-off in Hungary. Value Health. 2020. [In Press]. 20. Prevolnik Rupel V, Srakar A, Rand K. Valuation of EQ-5D-3L health states in Slovenia: VAS based and TTO based value sets. Zdr Varst. 2020;59(1):8-17. doi: 10.2478/sjph-2020-0002. 21. van Hout B, Janssen MF, Feng YS, Kohlmann T, Busschbach J, Golicki D, et al. Interim scoring for the EQ-5D-5L: mapping the EQ-5D-5L to EQ-5D-3L value sets. Value Health. 2012;15:708-15. doi: 10.1016/j. jval.2012.02.008. 22. Golicki D, Niewada M, van Hout B, Janssen MF, Pickard SA. Interim EQ-5D-5L value set for Poland: first crosswalk value set in Central and Eastern Europe. Value Health Reg Iss. 2014;4:19-23. doi: 10.1016/j. vhri.2014.06.001. 23. EuroQol organization. EQ-5D-5L crosswalk value sets. Accessed 4 June 2020 at : https://euroqol.org/eq-5d-instruments/eq-5d-5l-about/ valuation-standard-value-sets/crosswalk-index-value-calculator/. 24. Brooks R. The EuroQol Group: EuroQol: the current state of play. Health Policy. 1996;37:53-72.doi: 25. 10.1016/0168-8510(96)00822-6 26. Dolan P. Modeling valuations for EuroQol health states. Med Care. 1997;35:1095-108. doi: 10.1097/00005650-199711000-00002. 27. Zrubka Z, Beretzky Z, Hermann Z, Brodszky V, Gulácsi L, Rencz F, et al. A comparison of European, Polish, Slovenian and British EQ-5D­3L value sets using a Hungarian sample of 18 chronic diseases. Eur J Health Econ. 2019;20(Suppl 1):119-32. doi: 10.1007/s10198-019-01069­ 8. 28. R Core Team. R: a language and environment for statistical computing. R foundation for statistical computing, Vienna, Austria. Accessed 4 June 2020 at : https://www.R-project.org/. 29. Wickham H. ggplot2: elegant graphics for data analysis. New York: Springer-Verlag, 2016. 30. Wickham H, François R, Henry L, Müller K. dplyr: a grammar of data manipulation. R package version 0.8.4. Accessed 4 June 2020 at : https://CRAN.R-project.org/package=dplyr. 31. Golicki D, Jakubczyk M, Niewada M, Wrona W, Busschbach JJV. Valuation of EQ-5D health states in Poland: first TTO-based social value set in Central and Eastern Europe. Value Health. 2010;3(2):289­ 97. doi: 10.1111/j.1524-4733.2009.00596.x. 32. Golicki D, Jakubczyk M, Graczyk K, Niewada M. Valuation of EQ-5D-5L health states in Poland: the first EQ-VT-based study in Central and Eastern Europe. PharmacoEconomics. 2019;37:1165-76. doi: 10.1007/ s40273-019-00811-7. INJURY OCCURRENCE IN MODERN AND HIP-HOP DANCERS: A SYSTEMATIC LITERATURE REVIEW POJAVLJANJE POŠKODB PRI PLESALCIH MODERNEGA PLESA IN HIPHOPA: SISTEMATICNI PREGLED LITERATURE Eva URŠEJ1*, Petra ZALETEL2 1SMILE-E, Eva Uršej, s.p., Ulica Staneta Bokala 17, 4270 Jesenice, Slovenia 2University of Ljubljana, Faculty of Sport, Gortanova ulica 22, 1000 Ljubljana, Slovenia Received: Jul 28, 2019 Review Accepted: Jun 5, 2020 ABSTRACT Introduction: Dance-related injuries have become a field of great interest to researchers, with the most commonly reported injuries being those sustained by ballet dancers. However, there is a lack of research into injuries Keywords: sustained by those who perform modern and hip-hop dance. dance-related injuries, Methods: A systematic literature review using the MEDLINE research database was performed and a search carried risk factors, dancers’ out for full-text studies that investigate injuries in modern and hip-hop dance. characteristics Results: While a total of 74 hits were obtained from various searches, only nine studies were included in the systematic literature review. Six of them examined modern dancers, two examined break dancers and one examined hip-hop dancers. The results show that hip-hop dancers (and especially break dancers) sustain more injuries in comparison to modern dancers. The most common injuries are in the lower extremities, with studies revealing that overuse injuries occur in up to 71% of cases. Conclusions: The injury incidence rate in hip-hop dance seems to be higher compared to modern dance, chiefly because of the more demanding biomechanics involved and the dance techniques employed. Prevention management can have a positive effect on the number of injuries. IZVLECEK Uvod: Športne poškodbe so v zadnjih letih za raziskovalce postale vedno zanimivejše podrocje raziskovanja. Podobno velja tudi za poškodbe, povezane s plesom. Ta se je skozi desetletja precej spremenil, oblikovali so Kljucne besede: se novi plesni stili, razširil se je tudi v tekmovalnem smislu. Vecina raziskav je opravljenih pri plesalcih baleta, najveckrat profesionalnih, le malo raziskav pa lahko najdemo s podrocja poškodb v modernem plesu in hiphopu. poškodbe pri plesu, dejavniki tveganja, Metode: Sistematicni pregled literature je s pomocjo iskalnih kljucnih besed potekal v spletni podatkovni zbirki karakteristike plesalcev MEDLINE. Iskani so bili clanki s polnim besedilom, ki so raziskovali poškodbe v modernem plesu in/ali hiphopu. Rezultati: Najdenih je bilo 74 zadetkov, od katerih je bilo po branju naslova in izvlecka v nadaljnje branje vkljucenih 13 clankov, po branju polnega besedila pa jih je bilo v pregled literature vkljucenih devet. Šest študij je raziskavo opravilo na plesalcih modernega plesa, dve na plesalcih breakdancea in le ena na plesalcih hiphopa. Vecina raziskav je uporabila vprašalnik o znacilnostih plesalcev, plesni karieri in poškodbah, ena študija pa je v svojo osemletno raziskavo vkljucila obsežni preventivni ukrep za zmanjšanje poškodb. Rezultati vkljucenih študij kažejo, da plesalci hiphopa (še posebno breakdancea) utrpijo vec poškodb kot plesalci modernega plesa. Najpogostejše so poškodbe spodnjega uda (ligamentov in sklepov), ki mu sledijo poškodbe trupa. V vecini primerov gre za preobremenitve (do 71 %), precej manj je akutnih/travmatskih poškodb. Zakljucki: Raziskave kažejo, da je incidenca poškodb v hiphopu vecja kot v modernem plesu, predvsem zaradi zahtevnejše biomehanike gibanja in tehnike plesa. To velja zlasti za breakdance, pri katerem se pojavlja tudi vec poškodb zgornjega dela telesa kot pri ostalih plesnih zvrsteh. Preventivni programi lahko dokazano zmanjšajo število poškodb in posledicno tudi stroške, ki nastanejo zaradi zdravljenja in rehabilitacije. *Corresponding author: Tel. + 386 40 576 573; E-mail: eva.ursej@gmail.com © National Institute of Public Health, Slovenia. 1 INTRODUCTION While they are primarily performing artists, dancers are often also regarded as athletes. Performing dance at a high level requires sophisticated physical capacities (aerobic and anaerobic energy utilisation, muscular strength and endurance, speed, balance, coordination, agility, flexibility and motor control) allied to aesthetics (1). Professional and non-professional dancers alike are an embodiment of the achievements that can result from rigorous training and mastery of technique. As dance involves a high number of repetitions, dancers risk injury by exceeding the limits of their anatomical and physiological capabilities (2). Most dancers begin training at a young age, so there is the potential for injuries to have a significant impact on their future health (3). Injuries and health problems have result in financial outlays for individuals, dance companies and the health system (4). However, as an occupational group, modern and hip-hop dancers have received little attention in the health literature to date (5). Interest in dance-related injuries has widened in recent years, with several new reviews published (3, 5-7). However, most of these reviews are of research papers that investigate ballet injuries.indeed, this dance discipline is by far the most common point of interest for researchers (8). Although similarities between different dance styles exist, there are also differences in technique and in the movements dancers incorporate into their repertoire. Since its origins in the early part of the 20th century, modern dance has seen advances in technique brought about by choreographers and dancers such as Graham, Limon, Horton, Cunningham, Nikolais/Luis and Hawkins (9). Hip-hop dance, on the other hand, is a type of freestyle dance with a shorter history than that of modern dance. It was initially performed to hip-hop music by young people in the streets (10) and has several styles, divided into Old School (e.g. breaking, popping, locking) and New School (e.g. house, krumping, street jazz) (11). Street dance styles and modern dance have increased in popularity in recent years and are becoming part of many young people’s lifestyle (12). Moreover, dance schools are being set up in large numbers and are competing at national and international championships, and performing in theatres and at shows and concerts. All this requires class- and rehearsal-based training. Slovenia has approximately 2,500 registered dancers, half of them in hip-hop. Around 25% of all registered dancers compete in hip-hop and are under 15 years of age. Studies have shown that the most common modifiable risk factors for dance injuries are anthropometrics, joint range of motion, age and dance exposure (7). Because injury occurrence in modern and hip-hop dance is not yet well-documented (but seems to play a significant role in the health status of young dancers), the aim of this literature review was threefold: 1. to investigate the epidemiology of injuries in modern and hip-hop dance in order to highlight the magnitude of the problem; 2. to summarise the findings of previous studies regarding the risk factors that lead to injuries in modern and hip-hop dance; 3. to uncover opportunities for further research on modern and hip-hop dance injuries. 2 METHODS A systematic literature review of the MEDLINE (PubMed) research database was conducted in June 2019 in line with the recommendations of the Preferred Reporting Intensity for Systematic Reviews and Meta-Analyses (PRISMA) (13). The search for relevant articles was performed using MeSH Terms, as follows: (“wounds and injuries” [MeSH Terms] OR (“wounds” AND “injuries”) OR (“wounds and injuries” OR “injury”) AND “modern” AND “hip-hop” AND “break” AND (“dancing” [MeSH Terms] OR “dancing” OR “dance”). 2.1 Inclusion and Exclusion Criteria This review included full-text articles written in English and German published in the last 30 years. For original articles to be included, they needed to have investigated injuries among modern, hip-hop or break dancers. Other dance styles were excluded. We disregarded case studies and reports. Research on very uncommon injuries was also excluded. 2.2 Selection of Studies Two independent observers analysed the results to find potentially eligible studies. The articles were initially selected according to title. The abstracts were then reviewed. Studies available in full text that included key terms in the title or abstract were considered. To extend the number of hits, we also examined the references of all papers included. 3 RESULTS A literature review search revealed 74 studies. They were evaluated in accordance with the revised title and abstracts. Thirteen studies were then taken for further review. Only nine research papers met the inclusion criteria for the systematic literature review (Figure 1). All studies included in this literature review investigated injury occurrence among modern, hip-hop or break danc­ers. Six of them looked at modern dancers (14–19), two investigated injuries in break dance (20, 21) and only one paper addressed hip-hop dance (22). The research design, number of participants, main outcome measures and con­clusions of all nine studies are summarised in Table 1 (pro­spective studies) and Table 2 (retrospective studies). Table 1. Summary of prospective studies included in the systematic literature review. Parameter Research design Participants Main outcome measures Conclusions Bronner and Bauer, 2018 (14) Prospective cohort prognostic study Pre-professional modern dance students (n=180, F=140, M=40) Hypermobility and hypomobility, previous injuries and inferior technique/motor control were more likely to lead to injury. - Number of injuries (traumatic/ overuse, medical attention and time-loss, body region, tissue category, side) - Beighton score - Technique score - Muscle tightness - Previous injuries Lee et al., 2017 (15) Prospective cohort study Pre-professional dance students (n=66, F=40, M=26) - Injury prevalence - Injury characteristics (time­loss/non time-loss, acute/ overuse, new/recurrent) - Injury severity The number of dance exposures was more significantly associated with injury risk than hours of dance exposure. - Injury incidence - Relationship between dance exposure and injury - Relationship between reported injuries and risk factors Bronner and Wood, Prospective Professional modern - Reported injury (RI): Muscle and tendon 2017 (17) cohort study dance company diagnosis, traumatic/overuse, complaints affecting dancers (n=35, body region, activity the neck, lower leg F=18, M=17) - Time-loss injury (TLI) and low back/pelvic regions were common. - Complaints Ojofeitimi and Retrospective- Professional modern - Demographics An injury prevention Bronner, 2011 (19) prospective cohort study dancers in two dance companies - Injury incidence programme is effective in reducing injury-related (n1=30, n2=12) - Exposure costs and promoting - Injury location and diagnostic category - Injury mechanism (traumatic/ dancers’ health and well-being in a modern dance company. overuse) and severity - Injury-related costs F=female, M=male Table 2. Summary of retrospective studies included in the systematic literature review. Parameter Research design Participants Main outcome measures Conclusions Jacobs et al., Cross-sectional Dancers from nine - Self-reported injury (SRI) The prevalence of injury 2017 (16) study professional ballet and modern dance companies (n=260, - Self-estimated functional inability because of pain is high in professional dancers. The number of years dancing and Ba=178, Mo=82) the dancer’s rank are associated with injury in professional ballet dancers. Shah et al., 2012 (18) Self-reported retrospective study Professional modern dancers (n=184, F=135, M=49) Anonymous survey (demographics, forms of dance, modern dance techniques, other forms of exercise, health insurance, number of musculoskeletal injuries in the last year) Professional modern dancers suffer from a rate of injury similar to other groups of professional dancers. No significant difference between gender and age and incidence of injury. Ojofeitimi et Self-reported Intermediate, advanced, al., 2012 (22) retrospective study and expert hip-hop dancers (n=312, F=169, M=143, BD=68%, PL=21%, NS=11%) Kauther et al., Descriptive Professional (n=40) 2009 (20) retrospective and amateur (n=104) epidemiological break dancers study Online survey: -Demographics -Injuries over previous five years (locations, categories, severity, mechanism) Break dancers had a higher injury incidence compared with popping/ locking and New School dancers. Hip-hop dancers report injury rates higher than other dance forms, but similar to gymnastics. Self-reported questionnaire: Break dancing must be considered a potentially-General part (demographics, high-risk dancing sport. training time, length of warm-Even when suffering fromup and stretching time, other severe injuries, dancerssporting activities, extent interrupt training only forof medical treatment) limited periods of time. -Information about injuries (50 injuries in nine anatomical regions), severity (loss of training time), overuse/traumatic injury Cho et al., Descriptive Professional (n=23) - Self-reported questionnaire 2009 (21) retrospective and amateur (n=19) epidemiological break dancers - Question about injuries (ten different body parts) study - Radiographs of cervical spine, lumbar spine, shoulder, elbow, wrist, hip, knee and ankle - CT and MRI if needed Clinicians must enquire thoroughly into the nature of the activities that result in both unusual and common injuries in break dancers, and must educate them about safety. Careful screening, instruction and supervised training of break dancers will help to prevent injury. F=female, M=male, Ba=ballet, Mo=modern, BD=break dance, PL=popping/locking, NS=New School In four studies, the authors retrospectively examined inju­ry occurrence, and their location, severity and correlation with demographic and dance characteristics (18, 20–22); Jacobs et al. (16) compared injuries in modern dance and ballet in a cross-sectional study; three studies were pro­spective cohort studies (14, 15, 17); and one study ret­rospectively reported injuries and then prospectively investigated the effect of comprehensive management intervention on injury incidence and cost (19). Table 3. Summary of the main results of the studies included in the systematic literature review. Authors Dance style Reporting injury period Main results Bronner Modern 4 years Injuries/dancer: 2.32 (any I), 0.40 (TLI) and Bauer, 2018 (14) Injuries/inj. dancer: 3.34 (any I), 1.59 (TLI) Injuries/1000-h: 3.28 (any I), 0.57 (TLI) Traumatic inj./1000-h: 0.49 (any I), 0.19 (TLI) Overuse inj./1000-h: 2.8 (any I), 0.37 (TLI) Lee et al., 2017 (15) Modern 1 year Total injuries: 125 (86.2% dancers injured) Acute injuries: 51 (40.8%) Overuse injuries: 74 (59.2%) Number of injuries: 58 (Ba), 67 (Mo), 74 (TLI), 51 (NTLI) Injuries/1000-h: 2.27 (1.3 TLI, 0.92 NTLI, 2.11 Ba, 2.17 Mo) Bronner Modern 1 year Number of injuries: 20 (any I), 10 (TLI), 11 (traumatic I), 9 (overuse I) and Wood, Injuries/1000-h: 0.44 (any I), 0.22 (TLI), 0.24 (traumatic I), 0.2 (overuse I) 2017 (17) Ojofeitimi and Bronner, 2011 (19) 8 yearsModern Number of injuries: 217 Injuries/inj. dancer: 2.9 Cumulative incidence: 65% Injuries/1000-h: 0.41 Injury mechanism: 71% overuse, 28% traumatic, 1% other Jacobs et al., 2017 (16) 6 monthsBallet, modern Point prevalence of self-reported injury: - Ba: 54.8% (47.7-62.1), Mo: 46.3% (35.5-57.1) Injured: - Ba: 17 (9.6%), Mo: 9 (11.0%) Recovering from an injury: - Ba: 38 (21.5%), Mo: 11 (13.4%) Persistent injury: - Ba: 44 (24.9%), Mo: 19 (23.2%) Not injured: - Ba: 78 (44.1%), Mo: 43 (52.4%) Shah et al., Modern 1 year Injured: 150 (82%) 2012 (18) Injuries/dancer: 1.2±1.0 (M), 1.7±1.3 (F) Mechanism of injury: 57% overuse, 43% traumatic Injuries/1000-h: 0.59 Ojofeitimi et Hip-hop 1 year Injuries: 738 (232 injured dancers) al., 2012 (22) Time-loss injuries: 506 (205 injured dancers) Annual incidence: 237% (162% TLI) - BD: 278% (194%TLI), PL 152% (95% TLI), NS 144% (92% TLI) Injuries/inj. dancer: - BD 3.5 (2.8 TLI), PL 2.3 (1.7 TLI), NS 2.3 (1.6 TLI) Injury mechanism: 50% overuse, 42% landing, 36% twisting, 31% slipping Kauther et al., Break dance All career Number of acute injuries: 1,665 (1021 amateur BD, 644 professional BD) 2009 (20) Injuries/dancer: 11.6 (9.8 amateur BD, 16.1 professional BD) Overuse syndromes: 206 (123 amateur BD, 83 professional BD) Overuse syn./dancer: 1.4 (1.2 amateur BD, 2.1 professional BD) Cho et al., Break dance All career Injuries: 193 (133 professional BD, 60 amateur BD) 2009 (21) Injured dancers: 40 (95.2%) Injuries/dancer: 4.6 (5.78 professional BD, 3.16 amateur BD) I=injury, TLI=time-loss injury, NTLI=non time-loss injury, Ba=ballet, Mo=modern, M=male, F=female, BD=break dance, PL=popping/ locking, NS=New School The authors of five of the studies reported numbers of acute and traumatic injuries (14, 15, 17, 19, 20), while five studies presented injuries per 1,000-hours of dance expo­sure (14, 15, 17–19). Jacobs et al. (16) stated injury preva­lence only (Table 3). 4 DISCUSSION The purpose of this systematic literature review was to search for studies that investigated injuries in modern and hip-hop dance. As Russell (1) points out, studies have mostly investigated injuries in ballet. It is therefore not surprising to find that only 74 records were identified when searching only for injuries in modern, hip-hop and break dance. Furthermore, after eliminating review arti­cles, pilot studies and case reports, and excluding inap­propriate full texts, only nine studies were included in our literature review. 4.1 Systematic Review Results Six out of the nine studies included in our literature review used a survey or questionnaire to collect data on injuries. Besides general questions about personal and demograph­ic characteristics, and the nature, type, severity, location and frequency of injuries, they asked participants about dance exposure (15), pain (16), use of protective devices (21), amount of “headspin” training time (20), experience level (22) and the modern dance techniques they had studied (18). Only Lee et al. (15) investigated injuries pro­spectively for one dance year, with the other five all look­ing at injury occurrence over the previous six months (16), 12 months (17, 21) or over the length of a career (20, 21). An analysis of the surveys shows that modern dancers suf­fer more from overuse injuries (45-71%) (15, 17-19), while acute, traumatic injuries are more common among break dancers (89%) (20). Jacobs et al. (16) discovered that 44.1% of ballet dancers and 52.4% of modern dancers had never been injured, while 4.2% of break dancers had never re­ported an injury (20). This shows that biomechanics and the techniques of break dance carry a higher risk of acute injuries and the development of overuse injuries. Both studies that investigated injury rates among break danc­ ers revealed that professionals suffered significantly more injuries per person than amateurs (20, 21). This could be a result of the number of hours spent dancing and the danc­er’s career length. In modern dance, the injury incidence rate was 2.27/1,000 hours of dancing (15), while Ojofeitimi et al. (22) found different injury incidence rates for hip-hop dance according to dance style, as follows: 3.5 per break dancer, 2.3 per popping/locking dancer and 2.3 per New School dancer. A comparison between the number of time-loss injuries among modern and hip-hop dancers re­vealed that 59% of modern dancers sustained such injuries (15) compared to 68.5% of hip-hop dancers (22). The anatomical distribution of injuries was similar in all dance styles. The highest percentage of injuries occurred to the lower extremities (50-70%), approximately 20% of injuries were located in the trunk (mainly the lower back) and the least-injured parts were the upper extremities and the head (15, 18, 22). Injuries to the shoulder, wrist/ hand and head/cervical spine were more frequently re­ported in break dance than in modern and hip-hop dance (20, 21). The most common injuries were to joints and lig­aments (49%) (19); 28% suffered sustained muscle or ten­don strains (18) (29% of injuries (19)); and 21% of injuries involved dancers suffering from tendinitis or bursitis (18). Bronner and Bauer (14) discovered that hypermobility and hypomobility, previous injuries and poor dance-con­ trol technique contributed to injury occurrence. Fatigue and a lack of warm-up were also common risk factors for injuries (22). The literature does not contain suffi­cient information on risk factors in modern and hip-hop dance. However, Russell’s literature review (1) does offer some perspectives in support of reducing and preventing dance-related injuries. First, he encourages researchers to conduct screening tests; second, he recommends that dancers undergo additional physical training to comple­ment their technical dance training. He also suggests proper nutrition and rest (reduction of fatigue) for danc­ers. Ojofeitimi and Bronner (19) have shown that it is pos­sible to reduce total injury incidence by 34% by imple­menting comprehensive preventive measures. 4.2 Research Limitations and Strengths To our knowledge, this is the first review to compare in­jury occurrence between modern and hip-hop dancers. Vassallo et al. (5) reviewed injury incidence rates and characteristics across all levels of dance participation and identified a gap in the literature. This systematic litera­ture review clearly shows that there are too few studies that investigate injuries in hip-hop dance. Through a sys­tematic literature review, we were able to establish that injury rates in hip-hop dance were higher (and less fully investigated) than in modern (and other) dance styles. The greatest strength of this review is therefore the find­ing that hip-hop dancers need a special preventive train­ing programme to reduce injury occurrence and improve quality of life. 4.3 Potential for Further Research Since we did not find any prospective randomised con­trolled study that would examine the risk factors contrib­uting to injury occurrence, there is potential for conduct­ing such research in the near future. 10.2478/sjph-2020-0025 5 CONCLUSIONS This systematic literature review identified differences in injury incidence rates between modern and hip-hop dance (break dance in particular). As dance-related injuries seem to be of major concern, researchers may consider conducting further investigation into dance styles such as hip-hop, not only through self-report questionnaires but also by carrying out screening tests (23) and preventive programmes (which showed a reduction in dance-related injuries (24)), and by involving other healthcare workers. CONFLICT OF INTEREST The authors declare that no conflicts of interest exist. FUNDING This work was unfunded. ETHICAL APPROVAL The method used in this systematic literature review in­volves no ethical issues. No ethical approval was therefore necessary. REFERENCES 1. Russell JA. Preventing dance injuries: current perspectives. Open Ac­cess J Sports Med. 2013;4:199-210. doi: 10.2147/OAJSM.S36529. 2. Motta-Valencia K. Dance-related injury. Phys Med Rehabil Clin N Am. 2006;17(3):697-723. doi: 10.1016/j.pmr.2006.06.001. 3. Hincapié CA, Morton EJ, Cassidy JD. Musculoskeletal injuries and pain in dancers: a systematic review. Arch Phys Med Rehabil. 2008;89(9):1819-29. doi: 10.1016/j.apmr.2008.02.020. 4. Bahr R, Holme I. Risk factors for sports injuries - a methodolog­ical approach. Br J Sports Med. 2003;37(5):384-92. doi: 10.1136/ bjsm.37.5.384. 5. Vassallo AJ, Trevor BL, Mota L, Pappas E, Hiller CE. Injury rates and characteristics in recreational, elite student and professional danc­ers: a systematic review. J Sports Sci. 2019;37(10):1113-22. doi: 10.1080/02640414.2018.1544538. 6. Jacobs CL, Hincapié CA, Cassidy JD. Musculoskeletal injuries and pain in dancers: a systematic review update. J Dance Med Sci. 2012;16(2):74-84. 7. Kenny SJ, Whittaker JL, Emery CA. Risk factors for musculoskeletal in­jury in preprofessional dancers: a systematic review. Br J Sports Med. 2016;50(16):997-1003. doi: 10.1136/bjsports-2015-095121. 8. Smith TO, Davies L, de Medici A, Hakim A, Haddad F, Macgregor A. Prevalence and profile of musculoskeletal injuries in ballet dancers: a systematic review and meta-analysis. Phys Ther Sport. 2016;19:50-6. doi: 10.1016/j.ptsp.2015.12.007. 9. Weiss DS, Shah S, Burchette RJ. A profile of the demographics and training characteristics of professional modern dancers. J Dance Med Sci. 2008;12(2):41-6. Zdr Varst. 2020;59(3):195-201 10. Sato N, Nunome H, Ikegami Y. Kinematic analysis of basic rhythmic movements of hip-hop dance: motion characteristics common to ex­pert dancers. J Appl Biomech. 2015;31(1):1-7. doi: 10.1123/jab.2014­0027. 11. Physical graffitti, the history of hip hop dance by popmaster fable. Accessed 2019 Jul 22 at: https://www.daveyd.com/historyphysical­ grafittifabel.html. 12. Rajakumar M. Hip hop dance. ABC-CLIO, 2012. Accessed 2019 Jul 22 at: https://books.google.hr/books?id=jGZhfy9UaGIC. 13. Hutton B, Salanti G, Caldwell DM, Chaimani A, Schmid CH, Cameron C, et al. The PRISMA extension statement for reporting of systematic reviews incorporating network meta-analyses of health care interven­tions: checklist and explanations. Ann Intern Med. 2015;162(11):777­ 84. doi: 10.7326/M14-2385. 14. Bronner S, Bauer NG. Risk factors for musculoskeletal injury in elite pre-professional modern dancers: a prospective cohort prognostic study. Phys Ther Sport. 2018;31:42-51. doi: 10.1016/j.ptsp.2018.01.008. 15. Lee L, Reid D, Cadwell J, Palmer P. Injury incidence, dance exposure and the use of the movement competency screen (MSC) to identify variables associated with injury in full-time pre-professional dancers. Int J Sports Phys Ther. 2017;12(3):352-70. 16. Jacobs CL, Cassidy JD, Côté P, Boyle E, Ramel E, Ammendolia C, et al. Musculoskeletal injury in professional dancers: prevalence and associ­ated factors: an international cross-sectional study. Clin J Sport Med. 2017;27(2):153-60. doi: 10.1097/JSM.0000000000000314. 17. Bronner S, Wood L. Impact of touring, performance schedule, and definitions on 1-year injury rates in a modern dance company. J Sports Sci. 2017 Nov;35(21):2093-104. doi: 10.1080/02640414.2016.1255772. 18. Shah S, Weiss DS, Burchette RJ. Injuries in professional modern dancers: incidence, risk factors, and management. J Dance Med Sci. 2012;16(1):17-25. 19. Ojofeitimi S, Bronner S. Injuries in a modern dance company effect of comprehensive management on injury incidence and cost. J Dance Med Sci. 2011;15(3):116-22. 20. Kauther MD, Wedemeyer C, Wegner A, Kauther KM, von Knoch M. Break-dance injuries and overuse syndromes in amateurs and professionals. Am J Sports Med. 2009;37(4):797-802. doi: 10.1177/0363546508328120. 21. Cho CH, Song KS, Min BW, Lee SM, Chang HW, Eum DS. Musculoskeletal injuries in break-dancers. Injury. 2009;40(11):1207-11. doi: 10.1016/j. injury.2009.05.019. 22. Ojofeitimi S, Bronner S, Woo H. Injury incidence in hip hop dance. Scand J Med Sci Sports. 2012;22(3):347-55. doi: 10.1111/j.1600­0838.2010.01173.x. 23. Bahr R. Why screening tests to predict injury do not work-and proba­bly never will…: a critical review. Br J Sports Med. 2016;50(13):776-80. doi: 10.1136/bjsports-2016-096256. 24. Roussel NA, Vissers D, Kuppens K, Fransen E, Truijen S, Nijs J, et al. Effect of a physical conditioning versus health promotion intervention in dancers: a randomized controlled trial. Man Ther. 2014;19(6):562-8. doi: 10.1016/j.math.2014.05.008. National Institute of Public Health Trubarjeva 2, 1000 Ljubljana, Slovenia zdrav.var@nijz.si http://www.nijz.si/sl/nijz/revija-zdravstveno-varstvo ++386 1 2441 543 INSTRUCTIONS FOR AUTHORS Journal: Zdravstveno varstvo (ZV) ISSN 0351-0026 (print edition) / Slovenian Journal of Public Health (SJPH) ISSN 1854-2476 (electronic edition) Slovenian Journal of Public Health publishes internationally oriented articles on the broad area of public health and encourages interdisciplinary approach to public health. 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Any violation of the copyright will be legally persecuted. ZV/SJPH does not have article processing charges (APCs) nor article submission charges. The author receives one copy of the print issue in which the article is published. Nacionalni inštitut za javno zdravje Trubarjeva 2, 1000 Ljubljana, Slovenija zdrav.var@nijz.si http://www.nijz.si/sl/nijz/revija-zdravstveno-varstvo ++386 1 2441 543 NAVODILA AVTORJEM Revija: Zdravstveno varstvo (ZV) ISSN 0351-0026 (tiskana izdaja) / Slovenian Journal of Public Health (SJPH) ISSN 1854-2476 (elektronska izdaja) Navodila so v skladu z Uniform Requirements for Manuscripts Submitted to Biomedical Journals. Popolna navodila so objavljena v N Engl J Med 1997; 336: 309-15 in v Ann Intern Med 1997; 126: 36-47 in na spletni strani http://www.icmje.org. ETICNI STANDARDI Uredništvo sprejema v obdelavo le clanke s širšo mednarodno javnozdravstveno tematiko, ki še niso bili in ne bodo objavljeni drugje. Dele clanka, ki so povzeti po drugi literaturi (predvsem slike in tabele), mora spremljati dovoljenje avtorja in založnika prispevka, da dovoli naši reviji reprodukcijo. Oddan rokopis morajo prebrati vsi avtorji in se z njegovo vsebino strinjati. Raziskave na ljudeh (vkljucno s cloveškimi materiali in osebnimi podatki) morajo biti izpeljane v skladu s Helsinško deklaracijo in potrjene s strani nacionalne eticne komisije. V izjavi na koncu rokopisa morajo avtorji podati izjavo o etiki raziskav na ljudeh, ki mora vsebovati ime eticne komisije in referencno števiko obravnave. Porocanje o raziskavah na ljudeh brez potrdila eticne komisije zahteva dodatno razlago v poglavju o metodah dela. Na zahtevo Uredništva je avtor dolžan predložiti vso dokumentacijo o obravnavi raziskovalne etike njegovega rokopisa. Uredništvo si pridržuje pravico, da kontaktira eticno komisijo. Prav tako morajo avtorji, ki porocajo o ljudeh ali posredujejo javnosti njihovo slikovno gradivo, pridobiti dovoljenja vseh sodelujocih, da se z vkljucitvijo v raziskavo strinjajo (v primeru otrok so to starši ali skrbniki). Izjavo o pridobitvi teh dovoljenj morajo avtorji podati v poglavju o metodah dela. Uredništvo si pridržuje pravico vpogleda v to dokumentacijo. Raziskave na živalih morajo biti izpeljane v skladu z navodili “Animal Research: Reporting In Vivo Experiments” (ARRIVE) in potrjene s strani nacionalne eticne komisije. V poglavju o metodah dela in v izjavi na koncu rokopisa morajo avtorji podati izjavo o etiki raziskav na živalih z veljavno številko dovoljenja. V izjavi na koncu rokopisa morajo biti zapisani morebitni financni ali drugi interesi farmacevtske industrije ali proizvajalcev opreme ter inštitucij, povezanih z objavo v ZV/SJPH. Avtorji morajo na koncu rokopisa zapisati sledece izjave: CONFLICTS OF INTEREST (The authors declare that no conflicts of interest exist.) FUNDING (The study was financed by ... ) ETHICAL APPROVAL (Received from the… ali opis eticnega vidika raziskave) PLAGIATI Kadar uredništvo ugotovi, da je rokopis plagiat, se rokopis takoj izloci iz uredniškega postopka. Plagiatorstvo ugotavljamo s programom za odkrivanje plagiatov CrossCheck plagiarism detection system. ELEKTRONSKA ODDAJA PRISPEVKA Priporocamo uporabo videoposnetka z navodili za avtorje. Prispevke oddajte v elektronski obliki s pomocjo spletne aplikacije Editorial Manager, ki se nahaja na spletnem naslovu http://www.editorialmanager.com/sjph/. V uredništvo sprejemamo po pošti le še Izjave o avtorstvu in avtorskih pravicah, ki zahtevajo lastnorocni podpis. Prosimo, da jih pošljete hkrati z elektronsko oddajo prispevka na naslov: Nacionalni inštitut za javno zdravje, za revijo Zdravstveno varstvo, Trubarjeva 2, 1000 Ljubljana. V spletno uredniško aplikacijo se prijavite kot ‘avtor’. Prva prijava zahteva vnos podatkov o avtorju, vse naslednje prijave pa le še vnos podatkov za prijavo, ki jih na svoj elektronski naslov prejmete po prvi prijavi v sistem. Po uspešni prijavi izpolnite vsa zahtevana strukturirana polja. Potrdite izjavo, da vaš prispevek še ni bil objavljen ali poslan v objavo kakšni drugi reviji, da so prispevek prebrali in se z njim strinjajo vsi avtorji, da so raziskave na ljudeh oz. živalih opravljene v skladu z naceli Helsinško-Tokijske deklaracije oz. v skladu z eticnimi naceli. Avtorji, ki v objavo pošiljate raziskovalno delo, opravljeno s pomocjo nekega podjetja, to navedite na koncu rokopisa v izjavi o financiranju. Navedete lahko tudi do dva neželena recenzenta. Polje ‘Comments’ je namenjeno obveznemu predlogu treh recenzentov z imeni, nazivi, e-naslovi in zaposlitvijo. Navedete lahko tudi do dva neželena recenzenta. Podatke o avtorju in soavtorjih vnesite kar se da natancno in popolno. Naveden naj bo korespondencni avtor (s polnim naslovom, telefonsko številko in elektronskim naslovom), ki bo skrbel za komunikacijo z uredništvom in ostalimi avtorji. Jezik prispevka je anglešcina. Objavljamo izvirne znanstvene clanke, sistematicne pregledne znanstvene clanke, metodologije raziskav in vabljene uvodnike. Pri izvirnih, metodoloških in sistematicnih preglednih znanstvenih prispevkih morajo biti naslov, izvlecek in kljucne besede prevedeni tudi v slovenšcino. Naslov, kljucne besede in izvlecek se oddajajo dvojezicno v anglešcini in slovenšcini v strukturirana polja. Posebno polje za zapis v drugem jeziku obstaja le za izvlecek, preostale podatke vnesite v obeh jezikih v ustrezno isto polje. Prvi izvlecek je vselej v angleškem jeziku (do 250 besed - sistem vam besede sproti šteje), drugi pa v slovenskem jeziku (razširjen izvlecek - do 400 besed). Po vnosu strukturiranih podatkov oddajte še priponko - rokopis (od 1 Uvod naprej), ki ne sme zajemati podatkov, ki ste jih vnesli že pred tem v strukturirana polja, zlasti ne podatkov o avtorjih. Ime datoteke ne sme vkljucevati avtorjevih osebnih podatkov, prav tako ne imen ustanov, vkljucenih v pripravo rokopisa. Graficno in slikovno gradivo je kot ves rokopis v angleškem jeziku. Vkljucite ga v besedilo na mesto, kamor le-to sodi in ga opremite z naslovom. Oddate torej le en sam dokument, eno priponko. V Wordu uporabite možnost Postavitev strani/Številke vrstic (tako bo na robu vsake vrstice dokumenta dodana številka vrstice). Pri oddaji sledite napotkom, ki vam jih ponuja sistem, pomagate pa si lahko tudi z ‘Editorial Manager’s Tutorial for Autors’. Sistem najbolje deluje, ce uporabljate zadnjo razlicico Acrobata. Ce pri oddajanju rokopisa naletite na nepremostljive težave, se za pomoc obrnite na naslov uredništva: zdrav.var@nijz.si. V nadaljevanju podajamo še nekaj natancnejših napotkov. ROKOPIS Besedila naj bodo napisana z urejevalnikom Word for Windows 97-2003. Robovi naj bodo široki najmanj 25 mm. Znanstveni clanki naj imajo naslednja poglavja: uvod, metode, rezultati, razpravljanje in zakljucek. Uvodniki in sistematicni pregledni clanki so lahko zasnovani drugace, vendar naj bo razdelitev na poglavja in podpoglavja jasno razvidna iz velikosti crk naslovov. Poglavja in podpoglavja naj bodo številcena dekadno po standardu SIST ISO 2145 in SIST ISO 690 (npr. 1, 1.1, 1.1.1 itd.). DOLŽINA PRISPEVKOV Zahtevana dolžina prispevka je za vabljen uvodnik od 250 do 1000 besed, za znanstveni clanek (originalni, metodološki ali sistematicni pregledni) pa od 2000 do 4500 besed s slikovnim gradivom in literaturo vred. Revizija sme obsegati 5000 besed. NASLOV IN AVTORSTVO Naslov v angleškem in slovenskem jeziku naj bo kratek in natancen, opisen in ne trdilen (povedi v naslovih niso dopustne). Navedena naj bodo imena piscev z natancnimi akademskimi in strokovnimi naslovi ter popoln naslov ustanove, inštituta ali klinike, kjer je delo nastalo. Avtorji morajo izpolnjevati pogoje za avtorstvo. Prispevati morajo k zasnovi in oblikovanju oz. analizi in interpretaciji podatkov, rokopis morajo intelektualno zasnovati oz. ga kriticno pregledati, strinjati se morajo s koncno razlicico rokopisa. Samo zbiranje podatkov ne zadostuje za avtorstvo. IZVLECEK IN KLJUCNE BESEDE Izvlecek v angleškem in slovenskem jeziku naj bo pri znanstvenem in metodološkem clanku strukturiran in naj ne bo daljši od 250 besed v anglešcini in 400 besed v slovenšcini, izvlecki ostalih clankov so lahko nestrukturirani. Izvlecek naj vsebinsko povzema in ne le našteva bistvene vsebine dela. Izogibajte se kraticam in okrajšavam. Napisan naj bo v 3. osebi. Izvlecek znanstvenega clanka naj povzema namen dela, osnovne metode, glavne izsledke in njihovo statisticno pomembnost ter poglavitne sklepe (struktura IMRC - Introduction, Methods, Results, Conclusions). Navedenih naj bo 3-10 kljucnih besed, ki nam bodo v pomoc pri indeksiranju. Uporabljajte izraze iz MeSH - Medical Subject Headings, ki jih navaja Index Medicus. KATEGORIJA PRISPEVKA Kategorijo prispevka predlaga z vnosom v ustrezno polje avtor sam, koncno odlocitev pa sprejme urednik na osnovi predlogov recenzentov. Objavljamo izvirne znanstvene clanke, metodološke clanke, sistematicne pregledne znanstvene clanke in vabljene uvodnike. REFERENCE Avtorjem priporocamo, da pregledajo objavljene clanke na temo svojega rokopisa v predhodnih številkah naše revije (za obdobje zadnjih pet let). Vsako navajanje trditev ali dognanj drugih morate podpreti z referenco. Reference naj bodo v besedilu navedene po vrstnem redu, tako kot se pojavljajo. Referenca naj bo navedena na koncu citirane trditve. Reference v besedilu, slikah in tabelah navedite v oklepaju z arabskimi številkami ((1), (2, 3), (4-7)). Reference, ki se pojavljajo samo v tabelah ali slikah, naj bodo oštevilcene tako, kot se bodo pojavile v besedilu. Kot referenc ne navajajte izvleckov in osebnih dogovorov (slednje je lahko navedeno v besedilu). Seznam citirane literature dodajte na koncu prispevka. Literaturo citirajte po priloženih navodilih, ki so v skladu s tistimi, ki jih uporablja ameriška National Library of Medicine v Index Medicus. Uporabljajte numericno citiranje. Imena revij krajšajte tako, kot doloca Index Medicus (popoln seznam na naslovu URL: http://www.nlm.nih.gov). Navedite imena vseh avtorjev, v primeru, da je avtorjev šest ali vec, navedite prvih šest avtorjev in dodajte et al. Ce ima clanek/knjiga DOI številko, jo mora avtor navesti na koncu reference. PRIMERI ZA CITIRANJE LITERATURE primer za knjigo: 1. Anderson P, Baumberg P. Alcohol in Europe. London: Institute of Alcohol Studies, 2006. 2. Mahy BWJ. A dictionary of virology. 2nd ed. San Diego: Academic Press, 1997. primer za poglavje iz knjige: 3. Urlep F. Razvoj osnovnega zdravstva v Sloveniji zadnjih 130 let. In: Švab I, Rotar-Pavlic D, editors. Družinska medicina. Ljubljana: Združenje zdravnikov družinske medicine, 2002:18-27. 4. Goldberg BW. Population-based health care. In: Taylor RB, editor. Family medicine. 5th ed. New York: Springer, 1999:32-6. primer za clanek iz revije: 5. Florez H, Pan Q, Ackermann RT, Marrero DG, Barrett-Connor E, Delahanty L, et al. Impact of lifestyle intervention and metformin on health-related quality of life: the diabetes prevention program randomized trial. J Gen Intern Med. 2012;27:1594-601. doi: 10.1007/s11606-012-2122-5. primer za clanek iz revije, kjer avtor ni znan: 6. Anon. Early drinking said to increase alcoholism risk. Globe. 1998;2:8-10. primer za clanek iz revije, kjer je avtor organizacija: 7. Women’s Concerns Study Group. Raising concerns about family history of breast cancer in primary care consultations: prospective, population based study. Br Med J. 2001;322:27-8. primer za clanek iz suplementa revije z volumnom in s številko: 8. Shen HM, Zhang QF. Risk assessment of nickel carcinogenicity and occupational lung cancer. Environ Health Perspect. 1994;102(Suppl 2):275-82. 9. de Villiers TJ. The role of menopausal hormone therapy in the management of osteoporosis. Climacteric. 2015; 18(Suppl 2):19-21. doi: 10.3109/13697137.2015.1099806. primer za clanek iz zbornika referatov: 10. Sugden K, Kirk R, Barry HC, Hickner J, Ebell MH, Ettenhofer T, et al. Suicides and non-suicidal deaths in Slovenia: molecular genetic investigation. In: 9th European Symposium on Suicide and Suicidal Behaviour. Warwick: University of Oxford, 2002:76. 11. Shaw EH. An exploration of the process of recovery from heroin dependence: doctoral thesis. Hull: University of Hull, 2011. primer za elektronske vire: 12. EQ-5D, an instrument to describe and value health. Accessed January 24th, 2017 at: https://euroqol.org/eq­5d-instruments/. TABELE Tabele v angleškem jeziku naj bodo v besedilu prispevka na mestu, kamor sodijo. Tabele naj sestavljajo vrstice in stolpci, ki se sekajo v poljih. Tabele oštevilcite po vrstnem redu, vsaka tabela mora biti citirana v besedilu. Tabela naj bo opremljena s kratkim angleškim naslovom. V legendi naj bodo pojasnjene vse kratice, okrajšave in nestandardne enote, ki se pojavljajo v tabeli. SLIKE Slike morajo biti profesionalno izdelane. Pri pripravi slik upoštevajte, da gre za crno-beli tisk. Slikovno gradivo naj bo pripravljeno: • crno-belo (ne v barvah!); • brez polnih površin, namesto tega je treba izbrati šrafure (ce gre za stolpce, t. i. tortice ali zemljevide); • v linijskih grafih naj se posamezne linije prav tako locijo med samo z razlicnim crtkanjem ali razlicnim oznacevanjem (s trikotniki, z zvezdicami...), ne pa z barvo; • v grafih naj bo ozadje belo (tj. brez ozadja). Crke, številke ali simboli na sliki morajo biti jasni, enotni in dovolj veliki, da so berljivi tudi na pomanjšani sliki. Rocno ali na pisalni stroj izpisano besedilo v sliki je nedopustno. Vsaka slika mora biti navedena v besedilu. Besedilo k sliki naj vsebuje naslov slike in potrebno razlago vsebine. Slika naj bo razumljiva tudi brez branja ostalega besedila. Pojasniti morate vse okrajšave v sliki. Uporaba okrajšav v besedilu k sliki je nedopustna. Besedila k slikam naj bodo napisana na mestu pojavljanja v besedilu. Fotografijam, na katerih se lahko prepozna identiteta bolnika, priložite pisno dovoljenje bolnika. MERSKE ENOTE Naj bodo v skladu z mednarodnim sistemom enot (SI). KRATICE IN OKRAJŠAVE Kraticam in okrajšavam se izogibajte, izjema so mednarodno veljavne oznake merskih enot. V naslovih in izvlecku naj ne bo kratic. Na mestu, kjer se kratica prvic pojavi v besedilu, naj bo izraz, ki ga nadomešca, polno izpisan, v nadaljnjem besedilu uporabljano kratico navajajte v oklepaju. UREDNIŠKO DELO Prispelo gradivo z javnozdravstveno tematiko mednarodnega pomena posreduje uredništvo po tehnicni brezhibnosti v strokovno recenzijo trem mednarodno priznanim strokovnjakom. Recenzijski postopek je dvojno slep. Po koncanem uredniškem delu vrnemo prispevek korespondencnemu avtorju, da popravke odobri in upošteva. Popravljen cistopis vrne v uredništvo po spletni aplikaciji Editorial Manager. Uredništvo dopušca obravnavo najvec treh revizij. Ce tretja revizija rokopisa ne upošteva vseh pripomb recenzentov, se rokopis umakne iz uredniškega postopka. Sledi jezikovna lektura, katere stroške krije založnik. Med redakcijskim postopkom je zagotovljena tajnost vsebine prispevka. Avtor dobi v pogled tudi prve, t. i. krtacne odtise, vendar na tej stopnji upoštevamo samo še popravke tiskarskih napak. Krtacne odtise je treba vrniti v treh dneh, sicer menimo, da avtor nima pripomb. V uredništvu se trudimo za cim hitrejši uredniški postopek. Avtorji se morajo držati rokov, ki jih dobijo v dopisih, sicer se lahko zgodi, da bo clanek odstranjen iz postopka. Morebitne pritožbe avtorjev obravnava uredniški odbor revije. Za objavo clanka prenese avtor avtorske pravice na Nacionalni inštitut za javno zdravje kot založnika revije (podpiše Pogodbo o avtorstvu in avtorskih pravicah). Kršenje avtorskih in drugih sorodnih pravic je kaznivo. Prispevkov ne honoriramo in tudi ne zaracunavamo stroškov uredniškega postopka. Avtor dobi izvod tiskane revije, v kateri je objavljen njegov clanek.