Comparison of self-reported drug use with quantitative and qualitative urinalysis for assessment of drug use in treatment studies.

The effectiveness of substance abuse treatment programs can be monitored by self-reported drug use and objectively measured by qualitative and quantitative urinalysis. The advantages and disadvantages of each of these three methods of assessing drug use are reviewed. Data collected in a clinical trial of a behavioral treatment for cocaine abuse are used to evaluate the relationships among qualitative and quantitative urinalysis for cocaine metabolite and self-reported cocaine use. Qualitative and quantitative urine testing showed greater rates of drug use than that shown by self-report, though there were significant correlations between self-reported use and urine toxicology results. Benzoylecgonine concentrations in urine specimens supported the suggestions that rates of drug use as determined by qualitative urinalysis are artificially high due to carryover and were informative about subjects' patterns of use.