Agreement between urinalysis and self-reported drug use

One hundred fifty-eight drug users received an interview that included self -reported drug use. Opiate/cocaine use in the prior 48 hours was assessed b y urinalysis. Fifty-five subjects received a urine test after the interview and 103 were tested before. Chi-square tests were performed to determine i f agreement between serf-reported drug use and urine test results was assoc iated with timing of urine testing. The rate of agreement was 58% when the urine test was performed after the interview and 93% when performed before the interview (chi(2) = 28.6, p <.001). Conducting urine tests before an in terview can increase the accuracy of self-reports.