Assessment of psychiatric patients' risk of violence toward others.

Abstract

Evaluating a patient’s risk of committing violence against another person is one of the more common duties of the physician in the psychiatric emergency service. In the psychiatric emergency service at the University of Cincinnati Medical Center, with which the first author previously was affiliated, some 10 percent of patient visits are occasioned by concern about homicidal thoughts. Others have reported that up to 17 percent of patients seen in the psychiatric emergency service are homicidal, and that up to 5 percent are both homicidal and suicidal (1). This paper presents guidelines to help clinicians in the psychiatric emergency service evaluate patients who present with homicidal ideation or violent behavior. The guidelines are styled after a similar presentation on the assessment of suicide risk published in this column last year (2). General considerations As with suicide, no clinician can predict what is going to happen. The goal is risk assessment. The treatment decision must be related to the outcome of that risk assessment. In other words, the emergency clinician is not in the business of predicting an out come, but of making a logical assessment of a prevailing risk of violence in order to develop a reasonable treatment plan (3). A limited database on risk factors for violence exists, but researchers have concluded that, in general, the only factor associated with future violent behavior is a history of violence (4). In any case, epidemiological databases are largely irrelevant to the clinician in the psychiatric emergency service. Epidemiology focuses on longterm prevalence rates—for example, three-year rates—or lifetime prevalence rates. The data are related to the overall probability that a person will eventually attempt or commit a violent act. In the psychiatric emergency service, the clinician is con cerned with short-term risk, not the risk over future months or years. The definition of short-term risk is controversial. Does a homicide committed by someone who was evaluated two weeks earlier suggest faulty risk assessment? As we suggested in our discussion of suicide risk assessment (2), we consider a period of 24 hours as the short term. This period represents the maximum amount of time most emergency facilities can retain patients without admitting them as inpatients. As in the assessment of the suicidal