Prevalence and risk factors of violence by psychiatric acute inpatients: systematic review and meta-analysis - A 2019 update

Violence by patients in acute psychiatric wards affects both patients and staff. This study updates a 2015 meta-analysis of the prevalence of violent patients in acute psychiatric wards. Forty-two studies conducted in high-income countries were located in searches of the electronic databases PubMed, Scopus, and CINAHL. The pooled prevalence of reported acts of violence by patients was 18% (95% CI), although with very high heterogeneity (I2 = 98.7%, Q = 1735.3, p < 0.0001). Analysis of moderator variables found that 17.9% of the between-study heterogeneity was explained by the proportion of males (p = 0.0035), 16.4% by ward size (p = 0.0217), 12.8% by the proportion of involuntary patients (p = 0.0225), and 36.1% by the proportion of patients with alcohol-use disorder (p = 0.0007). The proportion of patients with other diagnoses, including psychotic illness, was not a source of heterogeneity. The continued high rate of violence confirms the need for improvement in the identification and containment of violent behavior in psychiatric wards in order to provide safer and more therapeutic environments.