High Prevalence of Recent Cocaine Use and the Unreliability of Patient Self-report in an Inner-city Walk-in Clinic

Abstract

To determine the prevalence of recent cocaine use and the reliability of patient self-reported cocaine use. A survey with blinded comparison to a criterion standard. Walk-in clinic of a large public hospital in metropolitan Atlanta, Ga. Male patients, aged 18 to 39 years, presenting to the triage desk for immediate care during weekdays. Of the 415 eligible men who agreed to participate (acceptance rate, 82%), the average age was 29.5 years, 91.6% were black, and 89% were uninsured. None. Comparison of self-reported illicit drug use with results from urinary immunoassays for benzoylecgonine, a major cocaine metabolite. Determination of which drug history questions produce the most accurate responses using anonymous urine testing as the criterion standard. Thirty-nine percent of patients tested positive for the presence of benzoylecgonine and were statistically more likely to be older, black, and have a prior history of sexually transmitted disease (P less than .01). Seventy-two percent of men with positive urinary assays denied illicit drug use in the 3 days prior to sampling. When queried with several formats, subjects with positive urine assays were more likely to admit to "any illegal drug" use (87.5%) than to the more specific "any form of cocaine" use (60.6%) within the prior year (P less than .0001). These results underscore the magnitude of cocaine abuse among black, inner-city men. Patient self-report of illicit drug use is highly inaccurate. Accuracy of self-report may be increased by asking less specific questions.