RESUMO
Violence risk assessment instruments are increasingly being used. Their use has, however, mostly been confined to forensic psychiatry for assessing the risk among perpetrators to repeat violent acts. In general psychiatry, very few studies of violence risk among discharged persons from acute inpatient units have been conducted. The available instruments are extensive and time consuming. This study aimed at the construction of a brief checklist. A 33-item scale, the PS (Preliminary Scheme), strongly influenced by the established HCR-20 (Historical, Clinical and Risk Management Assessment Scheme) was developed to undergo logistic regression analysis and possible item reduction. One hundred and ten patients from an acute inpatient unit, scored with PS at discharge, were monitored for violent episodes throughout the following year. Risk assessments and violence registrations were then compared. Of the 110 patients, 29 (26%) had acted violently during the follow-up, with the PS showing a definite association with post-discharge violence. Receiver operating characteristics (ROC) for the instrument yielded an area under the curve (AUC) of 0.71 (P<0.01). Regression analysis indicated that the number of PS items could be strongly reduced without losing predictive validity. Even a four-item checklist showed a higher AUC (0.77) than the PS did with all 33 items. The four items were: 1) Previous violence, 2) Substance use problems, 3) Lack of empathy and 4) Stress. The development of a brief risk assessment instrument with good predictive properties seems possible. Further clinical trials are planned. Ethical aspects of violence prediction must always be considered.
