title: Prevalence and Risk Factors of Violence by Psychiatric Acute Inpatients: A Systematic Review and Meta-Analysis.
abstract: BACKGROUND
  Violence in acute psychiatric wards affects the safety of other patients and the effectiveness of treatment. However, there is a wide variation in reported rates of violence in acute psychiatric wards.
  
  
  OBJECTIVE
  To use meta-analysis to estimate the pooled rate of violence in published studies, and examine the characteristics of the participants, and aspects of the studies themselves that might explain the variation in the reported rates of violence (moderators).
  
  
  METHODS
  Systematic meta-analysis of studies published between January 1995 and December 2014, which reported rates of violence in acute psychiatric wards of general or psychiatric hospitals in high-income countries.
  
  
  RESULTS
  Of the 23,972 inpatients described in 35 studies, the pooled proportion of patients who committed at least one act of violence was 17% (95% confidence interval (CI) 14-20%). Studies with higher proportions of male patients, involuntary patients, patients with schizophrenia and patients with alcohol use disorder reported higher rates of inpatient violence.
  
  
  CONCLUSIONS
  The findings of this study suggest that almost 1 in 5 patients admitted to acute psychiatric units may commit an act of violence. Factors associated with levels of violence in psychiatric units are similar to factors that are associated with violence among individual patients (male gender, diagnosis of schizophrenia, substance use and lifetime history of violence).
authors.affiliation: Psychiatric Epidemiology and Evaluation Unit, IRCCS Centro San Giovanni di Dio Fatebenefratelli, Brescia, Italy; Department of Public Health and Community Medicine, Section of Psychiatry, University of Verona, Verona, Italy.
authors.forename: Laura
authors.initials: L
authors.lastname: Iozzino
authors.affiliation: Psychiatric Epidemiology and Evaluation Unit, IRCCS Centro San Giovanni di Dio Fatebenefratelli, Brescia, Italy.
authors.forename: Clarissa
authors.initials: C
authors.lastname: Ferrari
authors.affiliation: Prince of Wales Hospital Sydney, Sydney, Australia; University of New South Wales, Sydney, Australia.
authors.forename: Matthew
authors.initials: M
authors.lastname: Large
authors.affiliation: St. Vincent's Hospital Sydney, Sydney, Australia; University of New South Wales, Sydney, Australia.
authors.forename: Olav
authors.initials: O
authors.lastname: Nielssen
authors.affiliation: Psychiatric Epidemiology and Evaluation Unit, IRCCS Centro San Giovanni di Dio Fatebenefratelli, Brescia, Italy.
authors.forename: Giovanni
authors.initials: G
authors.lastname: de Girolamo
mesh_terms: D000328:Adult; D001315:Australia / Q000453:epidemiology; D005060:Europe / Q000453:epidemiology; D005260:Female; D006778:Hospitals, Psychiatric / Q000706:statistics & numerical data; D006801:Humans; D007297:Inpatients / Q000523:psychology* / Q000706:statistics & numerical data; D008297:Male; D015995:Prevalence; D011604:Psychoses, Alcoholic / Q000453:epidemiology*; D012307:Risk Factors; D012559:Schizophrenia / Q000453:epidemiology*; D012737:Sex Factors; D012959:Socioeconomic Factors; D019966:Substance-Related Disorders; D014754:Violence / Q000706:statistics & numerical data*