Concordance between verbal report and urine screen of recent marijuana usein adolescents

This study compared the concordance of self-report for recent marijuana use with results obtained from urine drug screen. The sample consisted of adol escent sons of fathers with DSM-III-R lifetime substance use disorder (SUD) [high average risk (HAR); N = 75] and sons of fathers with no Axis 1 psych iatric or SUD [low average risk (LAR); N = 125]. To avoid recall bias, and to ensure that the timeframe for accurate detection was restricted to promo te accuracy, urine drug screen results were compared to self-reported marij uana use during the prior 48 h using an interview format. The HAR group of adolescents reported a higher rate of recent cannabis use and also had a hi gher rate of cannabis detection as measured in urine. The two groups did no t differ with respect to either over or under-reporting marijuana use. Over all, of 19 participants who obtained positive urine cannabis results, six ( 31.5%) verbally denied that they used marijuana within the previous 2 days. Among the 181 participants who obtained a negative urine drug screen, 20 s ubjects (11.5%) inaccurately asserted that they had used marijuana within t he prior 2 days. In total, 13% of the participants (26/200) inaccurately re ported recent cannabis use. These results underscore the need for caution i n interpreting the results of self-report methods documenting the prevalenc e of drug use among youth. (C) 2001 Elsevier Science Ltd. All rights reserv ed.