INCIDENCE, SEVERITY AND CHARACTERISTICS OF PATIENTS’ AGGRESSION IN 
ACUTE PSYCHIATRIC WARDS: DATA FROM A SLOVENIAN NATIONAL SURVEY
Andreja ČELOFIGA
 1
   , Jure KOPRIVŠEK
 1
   , Hojka GREGORIČ KUMPERŠČAK
 2 
  , Blanka KORES PLESNIČAR
 3 
1 
University Medical Centre Maribor, Department of Psychiatry, Ljubljanska 5, 2000 Maribor, Slovenia
2 
University Medical Centre Maribor, Child and Adolescent Psychiatry Unit, Ljubljanska 5, 2000 Maribor, Slovenia
3 
University Psychiatric Clinic Ljubljana, Chengdujska 45, 1260 Ljubljana, Slovenia
Received: Jun 06, 2023
Accepted: Sep 14, 2023
Original scientific article
*Correspondence: acelofiga@yahoo.com
10.2478/sjph-2023-0027 Zdr Varst. 2023;62(4):190-197
190
POJAVNOST, RESNOST IN ZNAČILNOSTI AGRESIVNEGA 
VEDENJA PRI PACIENTIH V AKUTNIH PSIHIATRIČNIH ODDELKIH: 
PODATKI IZ SLOVENSKE NACIONALNE RAZISKAVE
© National Institute of Public Health, Slovenia. 
Čelofiga A, Koprivšek J, Gregorič Kumperščak H, Kores Plesničar B. Incidence, severity and characteristics of patients’ aggression in acute psychiatric wards:  
Data from a Slovenian national survey. Zdr Varst. 2023;62(4):190-197. doi: 10.2478/sjph-2023-0027.
ABSTRACT
Keywords: 
Aggression
Incidence
SOAS-R
Mental  
disorders
Acute  
psychiatric  
wards
IZVLEČEK
Ključne besede: 
agresija
incidenca
SOAS-R
duševne  
motnje 
akutni  
psihiatrični  
oddelki
Aim: To evaluate the incidence, severity and characteristics of aggressive behaviour in patients hospitalized in acute psychiatric 
wards, as well as the association between patient characteristics and the incidence of recurrent aggressive behaviour.
Methods: A multicentre prospective study included all twelve acute wards in Slovenian psychiatric hospitals with a total 
capacity of 232 beds. Over five consecutive months, data on the number of treatment episodes involving aggressive 
behaviour and the number of aggressive incidents, their severity and characteristics were obtained using the Staff 
Observation Aggression Scale-Revised (SOAS-R). Patient- and event-based incident rates of verbal and physical aggression 
were calculated. The association between patient characteristics and recurrent aggressive behaviour was analysed. 
Patient characteristics data were extracted from hospital databases.
Results: 3,190 treatment episodes were included during a 5-month period. Aggressive behaviour was observed in 13.4% 
of treatment episodes, and 922 aggressive incidents were recorded, which resulted in 3.98 incidents per 100 occupied 
bed days and 9.48 incidents per bed per year. 74.1% of incidents were severe, and more than half of incidents included 
physical aggression. 75.5% of incidents were directed against medical staff. 5.9% of treatment episodes were involved 
in multiple aggressive incidents. Compared to patients with single incidents, patients with recurrent aggression had a 
less frequent main diagnosis of substance use disorders and a longer duration of hospitalization.
Conclusion: Monitoring the frequency and characteristics of aggressive behaviour allows comparisons with other 
studies and, more importantly, it is necessary for planning and assessing the effectiveness of preventative aggression 
management strategies.  
Namen: Oceniti pojavnost, resnost in značilnosti agresivnega vedenja pri pacientih, ki so hospitalizirani v akutnih 
psihiatričnih oddelkih in ugotoviti povezavo med demografskimi in nekaterimi kliničnimi značilnostmi pacientov in 
pojavnostjo ponavljajočega se agresivnega vedenja.
Metode: V multicentrično prospektivno raziskavo so bili vključeni akutni oddelki vseh slovenskih psihiatričnih bolnišnic. 
V obdobju petih zaporednih mesecev so bili pridobljeni podatki o številu hospitalnih obravnav z agresivnim vedenjem 
in številu agresivnih incidentov, njihovi resnosti in značilnostih. Za beleženje incidentov, njihovih značilnosti in oceno 
resnosti, je bil uporabljen slovenski prevod opazovalne Lestvice za oceno agresivnega vedenja: angl. The Staff Observation 
Aggression Scale – Revised (SOAS-R). Predstavljene so incidenčne stopnje verbalne in fizične agresije na ravni hospitalnih 
obravnav in dogodkov. Analizirana je povezava med značilnostmi pacientov in ponavljajočimi se agresivnimi incidenti. 
Demografski podatki pacientov in podatki o vodilni diagnozi, komorbidnih diagnozah, protivoljni hospitalizaciji in dolžini 
hospitalizacije so bili pridobljeni iz bolnišnične dokumentacije. Statistična analiza podatkov je bila izvedena z uporabo 
statističnega programskega paketa IBM SPSS 25.
Rezultati: V 5-mesečnem obdobju je bilo vključenih 3190 hospitalnih obravnav. Agresivno vedenje je bilo prisotno 
pri 13,4 % obravnav, zabeleženih je bilo skupno 922 agresivnih incidentov, kar predstavlja 3,98 incidentov na 100 dni 
zasedenih postelj in 9,48 incidentov na posteljo na leto. 74,1 % incidentov je bilo ocenjenih kot hudi, več kot polovica 
incidentov je vključevala fizično agresijo. 75,5 % incidentov je bilo usmerjenih proti zdravstveno-negovalnemu osebju. 
Pri skoraj polovici incidentov ni bil prepoznan sprožilec agresivnega vedenja, med ugotovljenimi sprožilci pa je bila 
najpogosteje opisana zavrnitev pacientovih zahtev in želja. Za zaustavitev agresivnega vedenja je bilo večinoma 
uporabljenih več ukrepov hkrati, najpogosteje pogovor s pacientom v kombinaciji z uvedbo omejitve s pasovi ali 
aplikacijo zdravila. 5,9 % hospitalnih obravnav je bilo vključenih v več agresivnih incidentov. Pacienti s ponavljajočimi 
se agresivnimi incidenti so imeli v primerjavi s tistimi z enkratnimi incidenti v manjšem deležu prisotno vodilno 
diagnozo duševna motnja, povezana z uporabo psihoaktivnih snovi ter daljše povprečno trajanje hospitalizacije. 
Zaključek: Agresivno vedenje pri pacientih, hospitaliziranih v akutnih psihiatričnih enotah, je pogosto povezano 
s poslabšanjem duševne motnje in je lahko neposreden vzrok za sprejem na oddelek. Pričakovanja, da bi lahko 
agresivno vedenje v takem okolju popolnoma odpravili, so najverjetneje nerealna. Zagotovo pa je smiselno spremljanje 
incidence in značilnosti agresivnega vedenja pacientov v psihiatričnem hospitalnem okolju, saj tako pridobljeni 
podatki omogočajo primerjavo z drugimi državami, še pomembneje pa je, da predstavljajo izhodišče za načrtovanje 
preventivnih strategij obvladovanja agresivnega vedenja in spremljanje njihove učinkovitosti.

1 INTRODUCTION
In patients with mental disorders, aggressive behaviour 
is three to five times more common than in the general 
population (1, 2). A recent systematic review of studies 
found that the prevalence of aggressive behaviour in 
psychiatric wards varied from 8-76% (3). Aggressive 
behaviour most commonly occurs in a hospital setting, 
often immediately upon admission to a psychiatric 
emergency room or an acute psychiatric ward. Data from 
a meta-analysis of 35 studies showed that the prevalence 
of aggressive behaviour in acute psychiatric units in 
developed countries ranged from 3 to 44% (4). Recurrent 
episodes of aggression are common, and studies show that 
only a minority of patients are responsible for more than 
half of all incidents (3). 
Most of the aggressive behaviour is directed at medical 
staff (4, 5). In psychiatric hospitals, 89% of the staff 
experience verbal aggression and more than half 
experience physical aggression (6). Verbal aggression 
is the most reported form of aggression, described in 
more than 80% of incidents, however, about half of the 
incidents involve physical aggression (5, 7). In a recent 
survey in Swiss psychiatric hospitals, almost 30% of nurses 
reported they had experienced a severe aggressive attack 
during their professional lives (8).
Risk factors for aggressive behaviour can be categorized 
into intrinsic factors related to the patient, and extrinsic 
factors related to the ward environment, staff and patient-
staff relationships (2, 9). Intrinsic risk factors include 
patient diagnosis, history of psychiatric treatment and 
aggressive behaviour, involuntary admission, length of 
hospital stay, psychopathological phenomena, biological 
factors, and sociodemographic factors (2, 3). A recently 
published systematic literature review found that high bed 
capacity occupancy, ward crowding, lack of daily structure 
or privacy, smoking and a restrictive environment were the 
most important ward factors associated with aggressive 
behaviour (3). Limitation of the patient’s requests or wishes, 
most often the desire to leave the hospital, is one of the 
most common triggers of aggression (10). On the other hand, 
interactions between patients and staff are often the main 
factor in the escalation and maintenance of aggression (3). 
Aggressive behaviour affects patient and staff safety, has 
a negative influence on their mental and physical health, 
and can lead to a bad reputation for the hospital (11). 
Both patients and staff feel victimized, but for different 
reasons. Patients report being victims of staff control 
within the restrictive ward environment, and staff feel 
victimized by patient aggression and an inappropriate 
work environment and organization. Such feelings have a 
significant negative impact on the therapeutic relationship 
(12, 13). The consequences for patients are longer hospital 
stays, more frequent use of coercive measures, and higher 
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doses of psychotropic drugs, all of which are associated 
with more complications (13, 14). Staff exposed to 
aggressive behaviour often experience feelings of anger, 
anxiety, guilt, shame, helplessness and disappointment. 
Decreased motivation and job satisfaction are common 
consequences (6, 7). Staff exposure to aggression is 
associated with mental disorders such as depression, 
anxiety symptoms, sleep problems, post-traumatic stress 
disorder and burnout syndrome, which occur primarily 
with chronic exposure and by inexperienced staff (11, 
15, 16). A recent study by Italian authors showed that 
exposure to verbal or physical aggression increased the 
incidence of burnout among mental health professionals 
(17). Absenteeism is more common among staff exposed to 
physical aggression and sexual harassment, and leaving or 
changing jobs are also common consequences (15, 18). The 
economic consequences associated with aggression and its 
management should not be overlooked. A Spanish study 
estimated the cost of specific interventions related to the 
management of aggression in an acute psychiatric ward 
to be 6.87% of the total annual hospitalization costs (19).
1.1 Aim of the study
To assess the incidence, severity and characteristics 
of patient aggressive behaviour in all Slovenian acute 
psychiatric wards.
2 METHODS
The study was the initial part of a large project of the 
Slovenian Psychiatric Association, which was carried out 
from 2018 to 2020, and was aimed at reducing aggressive 
behaviour in acute psychiatric wards. The study was 
approved by the Slovenian National Medical Ethics 
Committee (0120-74/2018/4).
2.1 Sample/participants/subjects
A multicentre, prospective study included acute psychiatric 
wards in Slovenian psychiatric hospitals, which serve 
inpatient psychiatric treatment for all inhabitants. There 
are two acute psychiatric wards in each hospital, one for 
male and one for female patients. The total bed capacity 
of all wards during the study period was 232 beds. 
2.2 Questionnaire/measures/data collection
During the study, the revised Staff Observation Aggression 
Scale (SOAS-R) was used in all hospitals to monitor 
aggressive incidents (20). In 2017, SOAS-R was translated 
into Slovenian in collaboration with the two authors of 
the original SOAS-R and was published in the journal 
of the Slovenian Psychiatric Association (21). SOAS-R 
defines aggression as any form of aggressive behaviour 
that threatens or harms the patient, others, or property. 

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The scale has five columns that cover specific aspects 
of aggressive behaviour: provoking factors, type of 
aggression, target, consequences and the measures used 
to stop aggression. At least one statement is marked 
in each column. Staff members witnessing aggressive 
behaviour complete the scale, and this takes about 1 
minute. SOAS-R is freely available for use in clinical 
practice and for research purposes (20). 
2.3 Data analysis
Data on the number of aggressive patients, the number 
of aggressive incidents and the severity of aggressive 
incidents were obtained. In our study, the term patient 
represents a hospitalization or treatment episode, as 
some patients were admitted more than once during the 
study. Incident severity was measured using the SOAS-R 
scoring system, ranging from 0 to 22 points (20). Incidents 
with a severity greater than 8 points were regarded as 
severe incidents, according to the scoring algorithm that 
has been developed over the years and is used by most 
research in which SOAS-R is used (22, 23). Severe incidents 
include physical attacks causing fear of harm to the victim, 
as well as attacks with dangerous objects directed at a 
person and incidents that cause pain or physical injury 
(24). Data on multiple aggressive incidents in an individual 
patient were obtained. Incidence rates for all aggressive 
incidents, severe incidents, verbal aggression and physical 
aggression were calculated. Physical aggression refers to 
incidents in which parts of the body, ordinary objects or 
potentially dangerous objects were used against things, 
people or oneself. Patients’ data were taken from the 
hospital databases and included demographic data, the 
main psychiatric diagnosis, comorbid diagnoses, data about 
involuntary hospitalization and length of hospitalization. 
Aggressive patient and incident characteristics were 
analysed using descriptive statistics. Categorical variables 
were presented as frequencies and percentages, whereas 
quantitative variables were provided as mean and standard 
deviations, or median and interquartile range. Patient-
based incidence rates were expressed as the proportion 
of patients with at least one aggressive incident and 
as the average number of incidents per patient. Event-
based incident rates were expressed as incidents per 100 
occupied bed days with a 95% confidence interval (95% 
CI), incidence per bed per year, and incidence per 100 
patients. Differences in the severity of various forms of 
aggression and differences in incident severity between 
shifts were analyzed using the Kruskal-Wallis H test. The 
relationship between aggressive patient characteristics 
and occurrence of recurrent episodes of aggression was 
assessed using Pearson Chi-square and Mann-Whitney 
U tests and logistic regression. The significance level of 
all statistical tests was determined at p<0.05. Statistical 
analysis was performed using IBM SPSS 25 (25).
3 RESULTS
3.1 Sample characteristics
Over a five-month period, 3,190 patients were included. 
53.4% of patients were male, the mean age was 48.86 
years (SD 18.317, range 14-97), the mean length of 
hospital stay was 9.68 days (SD 13.418, range 1-153), and 
the total number of occupied bed days was 30,895. 17.1% 
of patients were involuntarily hospitalized. The most 
common main diagnosis was schizophrenia, schizotypal 
and delusional disorders (F2), present in 35% of patients, 
followed by diagnoses of mental disorders due to the use of 
psychoactive substances (F1) in 20.2%, affective disorders 
(F3) in 17.5%, and organic mental disorders (F0) in 12.1%. A 
comorbid diagnosis of F1 was present in 20.7% of patients, 
and a comorbid personality disorder (F6) in 9.5%.
3.2 Frequency of aggressive incidents 
During the study, aggressive events were recorded in 427 
patients (13.4%). Among aggressive patients, 187 (43.8%) 
were involved in multiple aggressive incidents. 96 (22.5%) 
patients caused two incidents, 32 (7.5%) three and 59 (1.4%) 
four or more incidents. The latter group was responsible 
for 394 (42.7%) incidents. Over five consecutive months, 
922 aggressive incidents were recorded. The largest 
proportion of incidents was recorded during the day: 346 
(37.5%) in the morning and 325 (35.2%) in the afternoon 
shift. 191 (20.7%) aggressive incidents were recorded 
during the night shift. Time data was missing in 60 (6.5%) 
aggressive incidents. The average number of incidents per 
patient with aggressive behaviour was 2.2, ranging from 1 
to 24. Patient-based and event-based aggression incidence 
rates are shown in Table 1. 

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193
Patients, n
Proportion of patients with aggressive behaviour, %
Average number of incidents per patient
Incidents, n
Incidence per 100 occupied bed days, 95% CI 
 
Incidence per bed per year
Incidence per 100 patients
260
8.2
1.9
494
1.60 
[1.46;1.75]
5.08
15.49
352
11.0
1.9
683
2.21 
[2.05;2.38]
7.02
21.41
370
11.6
1.9
718
2.32 
[2.16;2.50)
7.38
22.51
427
13.4
2.2
922
2.98 
[2.80;3.18]
9.48
28.90
Physical Severe Verbal All Aggressive behaviour
Table 1.
Figure 1. Figure 2.
Patient-based and event-based aggression incidence rates.
Severity of different types of aggressive behaviour. Time-of-day variations in the severity of aggressive 
incidents.
3.3 Severity of aggressive incidents
At least one severe incident was reported in 11.0% of 
patients. Incident severity ranged from 0 to 21 points 
(mean 11.35, SD 4.262, median 12.00). 683 (74.1%) 
aggressive incidents were rated as severe. The severity 
of incidents involving physical aggression or both physical 
and verbal aggression was significantly higher than the 
severity of verbal incidents (H=192,665, df(2), p<0.001) 
(Figure 1). A statistically significant difference in the 
severity of aggressive incidents was observed between 
shifts (H=11.454, df(2), p=0.003). The average number 
of SOAS-R points was higher in the night and afternoon 
incidents than in the morning (Figure 2). 
Verbal: mean 9.36, SD 3.709, median 9.00, range 0-15; 
physical: mean 12.83, SD 4.084, median 14.00, range 
3-20; verbal and physical: mean 13.24, SD 3.855, 
median 14.00, range 2-21.
Morning: mean 10.87, SD 4.432, median 11.00, range 
0-20; afternoon: mean 11.86, SD 4.144, median 13.00, 
range 3-21; night: mean 12.11, SD 3.657, median 
13.00, range 3-20.
3.4 Characteristics of aggressive incidents 
In 47.9% of incidents, the reason for the aggressive behaviour 
could not be determined. Among the identified triggers, 
rejection of the patient´s request and other types of 
provocations not specifically defined in SOAS-R were most 
frequently described. Verbal aggression was present in 718 
(77.9%) incidents, while physical aggression was identified 
in 494 (53.6%) incidents. Verbal and physical aggression 
were present simultaneously in 290 (31.5%) of the aggressive 
incidents. 696 (75.5%) incidents were directed against staff, 
while 199 (21.6%) involved multiple targets, most often staff 
and patients or staff and objects. Several measures were 
usually taken simultaneously to stop aggression, the most 
common being talking to the patient in combination with 
physical restraint (47.2%), parenteral medication (19.6%) or 
oral drugs (18.3%). Detailed characteristics of aggressive 
incidents are shown in Table 2.

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Provocation
   No
   Other patients
   Help with ADL 
   Patient being denied something
   Required taking medication 
   Other
1
 
Means used by the patient
   Verbal aggression
   Ordinary objects:
      Chair, glass
      Other
2
   Parts of the body:
      Hand, foot, teeth 
      Other
3
   Dangerous objects:
      Knife
      Strangulation
      Other
4
Target of aggression
   Nothing
   Objects
   Other patients
   Patient self
   Staff members
   Other persons
Consequences for victims
   No
   Objects
   Persons:
   Felt threatened
   Pain
   Visible injury
   Need for treatment
Measures to stop aggression
   None
   Talk to patient 
   Calmly brought away
   Oral medication 
   Parenteral medication
   Held with force 
   Seclusion
   Physical restraints 
   Other measures
5
442 (47.9)
68 (7.4)
50 (5.4)
179 (19.4)
79 (8.6)
130 (14.1)
718 (77.9)
47 (5.1)
125 (13.6)
475 (51.5)
33 (3.6)
   
1 (0.1)
4 (0.4)
12 (1.3)
39 (4.2)
170 (18.4)
161 (17.5)
71 (7.7)
696 (75.5)
23 (2.5)
314 (34.1)
53 (5.7)
   
539 (58.5)
55 (6.0)
36 (3.9)
9 (0.9)
13 (1.4)
749 (81.2)
137 (14.9)
197 (21.4)
214 (23.2)
96 (10.4)
22 (2.4)
570 (61.8)
6 (0.7)
Aggressive 
incidents: n (%)
Characteristics of aggression
Table 2. Characteristics of aggressive incidents.
1
 Involuntary admission, loss of personal belongings, visits, lack 
of cigarettes, telephone conversation, court hearing.
2
 Door, tray, ashtray, painting, wheelchair, window, trashcan, 
plate, serving trolley, bottle, bedside table, bench.                                      
3
 Spitting, head.
4
 Lighter, scissors
5
 Transfer to another ward, discharge.
3.5 Recurrent aggressive incidents
Recurrent incidents accounted for 53.7% of all reported 
incidents. Severe aggression was observed in 90.9% of 
patients with recurrent aggressive incidents and in 75.8% 
of patients with a single aggressive incident. A comparison 
of sociodemographic and clinical characteristics of 
patients with single and recurrent aggressive incidents 
showed no difference in gender ( χ
2
(1)=1.821, p= 0.177), 
age (U=22023.500, p=0.742), involuntary hospitalization 
( χ
2
1)=0.960, p=0.327), main diagnoses F0 ( χ
2
(1)=0.004, 
p=0.950), F2 ( χ
2
(1)=2.686, p=0.101), F3 ( χ
2
(1)=0.130, 
p=0.719), and F6 ( χ
2
(1)=0.390, p=0.532), or comorbid 
diagnoses F1 ( χ
2
(1)=1.442, p=0.230) and F6 ( χ
2
(1)=0.195, 
p=0.659). The differences between patients with a single 
and recurrent incident were in the main diagnosis F1 
(single: 23.8%, multiple: 13.4%, χ
2
(1)=7.300, p=0.007) and 
in the average duration of hospitalization (single: median 
6.00, range 1-113; multiple: median 14.00, range 1-153, 
U=14772.500, p<0.001). These findings were also confirmed 
by logistic regression ( χ
2
(1)=47.504, p<0.001, Nagelkerke 
R2=0.141). Holding other predictors constant, with each 
additional day of hospitalization, the odds of repeated 
incidents increase by 3.6% (OR=1.036, 95% CI [1.021;1.051], 
p<0.001). The presence of the main diagnosis F1 represents 
a protective factor for multiple aggressive incidents, 
and the odds were 69% lower than in patients with other 
diagnoses (OR=0.310, 95% CI [0.129;0.741], p=0.008).
4 DISCUSSION
The first Slovenian data on aggressive behaviour for all 
acute psychiatric wards are presented. Although the 
frequency of aggressive behaviour in acute psychiatric 
settings in developed countries varies greatly (3, 4), on 
average the data are comparable to our national data. 
The proportion of aggressive patients in our sample was 
13.4%, which is comparable to the results of the Swiss 
study by Abderhalden et al. (26) but slightly lower than a 
meta-analysis of 35 studies conducted in acute psychiatric 
wards in developed countries (17%) showed (4). The 
incidence of aggressive events per bed per year was 9.5, 
which is comparable to the average rate (9.3) observed in 
European acute psychiatric wards (27). Compared to the 
study from Abderhalden et al. (26), the incidence rate per 
100 treatment days was 40 to 60% higher in the Slovenian 
population. The lower incidence in the Swiss survey may 
reflect the fact that, in addition to closed wards, there 
were also part-time closed wards included and, to a 
lesser extent, wards without seclusion rooms, where the 
patients with the most severe pathology, who are most 
often aggressive, are less likely to be treated. In Slovenia, 
acute psychiatric wards are closed wards, and patients 
are treated for a variety of psychopathology, including 
organic mental disorders and delirium, which are known to 

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195
be associated with aggressive behaviour (28). Aggression 
risk assessment and staff de-escalation training are still 
sporadic, and a systematic prevention strategy is lacking 
in all hospitals.
A large proportion of aggressive incidents were severe, 
with the mean severity of aggression slightly higher 
than in other similar studies (5, 26). The high proportion 
of severe incidents in our study may be due to the 
underestimation of less severe incidents without clear 
perceived consequences. Staff working with patients with 
severe mental disorders often perceive mild, especially 
verbal forms of aggression, as normal behaviour of 
patients with an acute mental disorder rather than as a 
distortion (11). Increased tolerance of aggressive behaviour 
and the perception of aggression as “part of the job” 
are particularly pronounced among staff working with 
patients with mental disorders, the elderly population and 
in emergency rooms (13, 29). Psychiatric nurses reported 
lower levels of stress after being verbally attacked than 
other nurses (30). Therefore, it is possible that the high 
proportion of severe incidents in our study is due to the 
underestimation of less severe incidents. On the other 
hand, the high rate of severe incidents may also be related 
to the subjective perception of a greater proportion of 
aggressive behaviour as threatening. According to some 
researchers, the item “being threatened” in the SOAS-R 
scale is unclear, as it is not further defined to whom the 
threat refers (5). The assessment of being threatening is 
subjective, but at the same time, this item contributes a 
high proportion (6 points) to the total score on the SOAS-R. 
Thus, most incidents that cause a feeling of danger are 
assessed as severe. Feeling threatened is one of the 
most frequently described consequences of aggressive 
behaviour (10), which is confirmed by our findings. 
Abderhalden et al. found that up to 46% of incidents of 
verbal aggression were classified as severe, and 43% were 
followed by the use of coercive measures (26). Our study 
found an even higher rate of severe verbal incidents (59.8%). 
Approximately half of the incidents assessed as severe 
were followed by the introduction of physical restraints, 
which indicates the seriousness of these incidents, as the 
decision to introduce restraints is usually made within 
the staff team with the psychiatrist’s approval and is not 
based on a risk assessment by an individual staff member. 
Seclusion is almost never used in acute psychiatric wards 
in Slovenia, mainly due to inadequate room capacities and 
the inability to adequately monitor such patients. 
In almost half of the incidents in our study, staff did 
not identify a trigger for aggressive behaviour, which 
is consistent with findings from other researchers (5, 
26). Some authors report that the reason for the high 
proportion of unrecognized causes may be due to the 
limited number of possible trigger items listed in SOAS-R 
(5). However, the staff who complete the scale could list 
other causes that they recognize. In fact, the staff in our 
survey entered specific causes of aggression under the item 
“other provocations” on the SOAS-R in 14% of incidents. 
The attitudes of staff and patients related to the causes of 
aggressive behaviour differ. From patients’ perspectives, 
aggressive behaviour is associated with staff attitude and 
interpersonal skills, inadequate communication, the use 
of coercive intervention or a controlling approach, ward 
structure and treatment procedures (31). On the other 
hand, staff often do not recognize their involvement 
in the process of escalating aggression and attribute 
aggressive behaviour to internal patient factors (9). 
However, the systematic review of seventy-one studies 
revealed that staff-patient interaction was the most 
frequent antecedent of aggression, precipitating 39% of 
all incidents (32). Among the identified triggers, in our 
research, rejection of the patient’s requests was the 
most frequently described, as some other authors also 
noted (10). This fact could be important in the planning 
of interventions aimed at reducing aggressive behaviour, 
as most de-escalation programmes involve interventions 
focused on this issue.
In our study, the highest proportion of aggressive incidents 
were recorded during the day, but these were rated as less 
severe compared to incidents in the afternoon and night 
shifts. More frequent aggressive behaviour during the day 
may be related to more staff on the ward, more activities, 
court hearings and visits. During the day, patients are more 
often faced with various rejections of their requests, such 
as being discharged, reducing therapy, or transferring to 
an open ward, which are the most common triggering 
factors of aggressive behaviour identified in our and other 
studies (24). Among incidents on the night shift, a sense of 
threat was more commonly reported, which may also be 
due to subjective experience associated with fewer staff 
on the ward at night. The staff-to-bed ratio during the 
study ranged from 0.1 to 0.3, which is low compared with 
some other European countries (33). Weekend and night 
shifts have the lowest ratio.
Consistent with previous studies, approximately 20% 
of aggressive patients accounted for nearly half of all 
incidents (3). Among patients with recurrent incidents, 
the proportion of those with a main diagnosis of F1 was 
lower compared to patients with a single incident. This 
can be explained by the temporary and transitory effect 
of intoxication on aggressive behaviour. Patients with 
recurrent incidents had on average longer hospitalizations, 
as shown by the results of other studies (34). However, the 
cause-and-effect relationship is not entirely clear. Patients 
with longer hospitalizations often have severe mental 
disorders associated with an increased risk of aggression. 
On the other hand, patients with longer hospitalizations 
have a longer period in which incidents may occur.

10.2478/sjph-2023-0027 Zdr Varst. 2023;62(4):190-197
196
4.1 Strengths and limitations
This is the first study in Slovenia to examine the frequency 
and characteristics of aggressive behaviour in patients in the 
acute psychiatric wards. Due to the large and representative 
sample size, the five-month prospective study design, 
and the use of a standardized reporting instrument, the 
incidence rates could be representative for acute wards in 
Slovenia and useful as a reference for comparative research 
and studies aimed at reducing aggression. 
The study has some limitations. Our findings cannot 
be generalized outside the acute settings of Slovenian 
psychiatric hospitals. Possible victims of the patient’s 
aggressive behaviour were staff, other patients, 
themselves and objects. However, if not hospitalized, 
the same patients usually have a wider range of potential 
victims in their home or workplace, where violence is 
common, particularly in the period before hospitalization 
(35). Nurses’ reports of incidents are subject to potential 
observer bias, and the lack of inter-rater reliability 
assessment limits the study’s power. Underreporting 
incidents and incorrect completion of the SOAS-R may 
affect the outcomes, which were minimized by introducing 
the scale into clinical practice before the study and by 
checking the consistency between reported incidents and 
patient records. The high percentage of serious incidents 
may be a sign that verbal-only incidents are underreported. 
The problem with the severity assessment, on the other 
hand, is the inability to exclude the subjective component 
of the threat experience. We examined the effect of 
primary diagnosis and comorbid diagnoses F1 and F6 
on the occurrence of recurrent aggression. It should be 
emphasized that the choice of the main diagnosis may be 
influenced by several factors, such as insurance policy or 
the psychiatrist’s own judgment. 40.9% of our sample had 
an F1 diagnosis, which is important to note as substance 
use disorders have the highest population-level impact in 
terms of interpersonal violence (36). 
4.2. Implications for practice and further research
Monitoring the frequency and characteristics of aggressive 
behaviour helps identify high-risk situations and implement 
preventative measures, and it can be useful for planning 
individualized treatment with targeted interventions. 
Optimizing the use of resources, such as allocating 
additional personnel, safety measures or de-escalation 
training, where aggressive behaviour is common, may 
be another potential benefit. Tracking the frequency 
of aggression is beneficial for quality improvement as it 
allows investigation of the impact of different treatment 
approaches, and development of specific interventions to 
prevent or manage aggressive behaviour. Assessing the 
effectiveness of interventions for managing aggression 
and monitoring the long-term outcomes of patients with 
aggression are interesting areas of research.
5 CONCLUSION
In Slovenia, preventive strategies and mechanisms for 
managing aggression should be introduced in all psychiatric 
hospitals. Assessing the frequency, characteristics and 
long-term monitoring of aggressive behaviour may be a 
good start to this challenging task. 
ACKNOWLEDGEMENT
We would like to acknowledge and thank all colleagues 
from Slovenian Psychiatric Hospitals who participated 
in the survey: A. Plemenitas, B. Stojceska, M. Klemen, 
S. Klasinc, D. Lunder, M. Strbad, I. Vucko Miklavcic, T. 
Prokselj, D. Loncnar, M. Mavri Tratnik, M. Salkic, V. Bozic, 
A. Trpin Kataric.
CONFLICTS OF INTEREST
The authors declare that no conflicts of interest exist.
FUNDING
The research was conducted as part of a research project 
of the University Medical Centre Maribor (IRP 2018/1-09).
ETHICAL APPROVAL
Ethical approval to conduct the study was obtained from 
the National Medical Ethics Committee of the Republic of 
Slovenia (NMEC), No. 0120-74/2018/4.
AVAILABILITY OF DATA AND MATERIALS
Data used in this study are available upon request.
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