Screening urine for drugs of abuse in the emergency department: do test results affect physicians' patient care decisions?

BACKGROUND Drug abuse is a frequent factor in emergency department (ED) visits. Although commonly performed, qualitative testing of urine for drugs of abuse (u-DOA) is inherently limited in its ability to establish the identity, timing or dose of substances used. Previous studies have demonstrated these limitations, but their designs cannot be used to determine whether the results of u-DOA tests affect physicians' patient care decisions. Our objective was to determine the impact of u-DOA testing on the care of patients who present to the ED. METHODS All adults 18 years of age or older who had u-DOA testing in 2 urban teaching EDs were eligible. Victims of vehicular trauma or sexual assault were excluded. Just prior to communicating the results of u-DOA testing for a patient, an investigator interviewed the ordering physician or consultant physician about the patient care plans for that patient. Test results were then revealed, and the questions immediately repeated. This design isolated the impact of knowledge of u-DOA test results on physicians' patient care decisions. Any intended changes in patient care plans reported by the interviewed physician were compared to a priori criteria for substantive change and then subsequently reviewed by an independent expert to determine whether that change was justified. RESULTS Of the 110 u-DOA test results studied and the resultant 133 opportunities to influence physician management plans, there were 4 reported changes in management. One management change was judged to be substantive, but none of the 4 reported changes were considered by the independent expert reviewer to be justified. Urine-DOA testing thus led to a justified change in management in 0/133 instances (95% confidence interval 0%-2.3%). CONCLUSIONS Urine-DOA is rarely helpful in guiding patient care decisions in the ED. The results of this study call into question the need for this test in the ED setting.