For Juvenile Drug Offenders . A Summary of Research Conducted by Tom Mieczkowski, Ph.D. Estimates of the incidence and prevalence of drug use among juveniles have been derived, historically, from self reports obtained during interviews. However, comparison of survey responses with urinalysis results has shown that self-reported drug behavior does not accurately reflect the extent of drug use. Urine-based testing consistently detects more drug use than is revealed by self reports, suggesting that estimates based on surveys alone underreport drug use. For example, the maximum retrospective period allowed by urinalysis for detecting cocaine or most opiates at currently accepted cutoff values is approximately 48 to 72 hours, as determined by the rate at which these drugs clear the body.
Hair analysis is one such methodology.
Hair entraps drugs or their metabolites for much longer periods than urine and represents an alternative medium for estimating the use of rapidly excreted drugs. The original study showed that hair analysis revealed seven times as much cocaine use as was detected by urinalysis. The findings from the replicated study confirmed those made earlier, although only a fourfold difference was found between hair and urine assay results for cocaine. Participation in the study was voluntary. Study findings o Self reports.