Characteristics of aggression in a German psychiatric hospital and predictors of patients at risk.

This study investigated the aggressive behaviour of all mentally ill patients within a whole psychiatric hospital with a catchment area of 325 000 inhabitants over a 1-year period (i) to assess the 1-year prevalence and characteristics of aggressive episodes and index inpatients, and (ii) to identify predictors of patients at risk by a multivariate approach. Staff Observation of Aggression Scale was used to assess aggressive behaviour. Characteristics of index inpatients were compared with those of non-index inpatients. Logistic regression analysis was applied to identify risk factors. A total of 171 out of 2210 admitted patients (7.7%) exhibited 441 aggressive incidents (1.7 incidents per bed per year). Logistic regression analyses revealed as major risk factors of aggression: diagnoses (organic brain syndromes OR = 3.6, schizophrenia OR = 2.9), poor psychosocial living conditions (OR = 2.2), and critical behaviour leading to involuntary admission (OR = 3.3). Predictors of aggressive behaviour can be useful to identify inpatients at risk. Nevertheless, additional situational determinants have to be recognized. Training for professionals should include preventive and de-escalating strategies to reduce the incidence of aggressive behaviour in psychiatric hospitals. The application of de-escalating interventions prior to admission might be effective in preventing aggressive behaviour during inpatient treatment especially for patients with severe mental disorders.