Substance use in a school-based clinic population: use of the randomized response technique to estimate prevalence.

Students attending school-based clinics acknowledge only minimal involvement with drug or alcohol use. In order to explain this unanticipated finding, we used a statistical method called randomized response to study adolescents in one school-based clinic. The sample consisted of 133 students (57% female; 75% black, 20% Hispanic, 5% other; and 58% grades 9-10, 42% grades 11-12). Using both lifetime and 30-day prevalence rates, these students revealed more cigarette smoking and alcohol use on randomized response than they had on questionnaires completed earlier the same academic year, minimal involvement with either marijuana or cocaine use by either method, and a similar amount of sexual activity by both methods. This study demonstrates that randomized response can be a useful method to generate more truthful group responses from adolescents.