• aggression;
  • violence;
  • psychiatry;
  • psychotic disorders

Objective:  Research on the prevalence and causes of in-patient aggression has been hindered by the use of different methods for measuring aggression. Since Palmstierna and Wistedt presented the Staff Observation Aggression Scale (SOAS) in 1987, this data collection method has been used in various studies, which may make comparisons more useful.

Method:  Studies with SOAS aggression data were compiled using MEDLINE, the Internet, and references from SOAS papers.

Results:  Reviews of studies on psychometric properties suggest fair to good inter-rater reliability and validity for SOAS assessments. The number of aggressive incidents per patient per year found on acute admissions wards (n = 38) considerably varied, with a range of 0.4–33.2 incidents (mean = 9.3).

Conclusion:  Although the aggression data included in the present review were obtained in highly comparable ways, substantial differences in aggression rates between wards were still found. Some countries (e.g. the Netherlands) appear to have a relatively high incidence of aggression on acute wards.