The prediction of imminent aggression in patients with mental illness and/or intellectual disability using the Dynamic Appraisal of Situational Aggression instrument.

Objective: The aim of this paper was to determine whether imminent aggression in psychiatric inpatients can be accurately predicted using a structured risk assessment instrument, the Dynamic Appraisal of Situational Aggression (DASA). Methods: This prospective validation study involved 10 013 DASA risk assessments of patients residing in a psychiatric hospital. Twenty-four hours after the risk assessment, psychiatric nurses documented whether patients had behaved aggressively towards others or whether they had deliberately damaged property. They also noted the target of aggression, whether towards staff, patients or property. Results: The predictive validity of the DASA varied according to the type and target of aggression. The prediction of any aggressive behaviour, irrespective of type of aggression or target, was significantly greater than chance (AUC = 0.69). The strongest predictive accuracy (AUC = 0.80) was for physical aggression towards staff. Conclusions: These results suggest that imminent aggression in psychiatric hospitals may be able to be accurately predicted by psychiatric nurses using a structured risk assessment instrument.