This study compared two frequently used measures of drug use, urine te
sting and self-report in a sample of subjects currently enrolled in me
thadone treatment for a minimum of six months. A comparison between th
e percentage of positive opiate urine screens and subjects' self-repor
ted opiate use indicated that more patients self-reported opiate use (
80%) than had been detected by urinalysis (57%). Similar results were
found for cocaine use. We present arguments that a more inclusive meth
od of measuring drug use during treatment should include the combinati
on of both urinalysis and self-reports.