Utility of routine drug screening in a psychiatric emergency setting.

Objective: The study determined whether dispositions from an urban psychiatric emergency service would differ between patients who received a mandatory urine drug test and those who may or may not have had a test based on the attending psychiatrist's clinical judgment. The accuracy of clinicians' suspicion of substance use among mandatorily screened patients was also examined.

Methods: A total of 392 consenting patients presenting to an urban psychiatric emergency service were randomly assigned to a mandatory-screen group (N=198) or a usual-care group (N=194). Physicians ordered screens based on clinical judgment. Additional screens were performed without physicians' knowledge for patients in the mandatory-screen group for whom no screen was ordered. Demographic and clinical information, results of drug screens, and information about dispositions were collected from clinical charts or hospital databases.

Results: No difference in dispositions was found between the mandatory-screen group and the usual-care group. Survival analysis did not reveal a difference between the two groups in length of stay in inpatient psychiatric units. As for accuracy of physicians' suspicion of substance use, positive drug screens were recorded for 10.2 percent of the 198 patients in the mandatory-screen group who did not admit drug use or for whom physicians did not expect drug use. A total of 39.3 percent of the patients who were suspected of use and 88.2 percent of those who admitted use had positive drug screens. Only 20.8 percent of patients who denied substance use had positive screens.

Conclusions: Routine urine drug screening in a psychiatric emergency service did not affect disposition or the subsequent length of inpatient stays. The results do not support routine use of drug screens in this setting.