Self-Reported Methamphetamine Use Versus Biological Testing Among Treatment-Seeking Patients

Background: The validity of self-reported methamphetamine use among treatment-seeking patients has been reported as inconsistent and therefore inconclusive. Objectives: To evaluate the validity of self-reported methamphetamine use versus urinalysis in patients with methamphetamine use disorder at a drug treatment center. Methods: In this cross-sectional study, we enrolled 71 individuals with methamphetamine use disorder who were referred to the Iranian National Center for Addiction Studies (INCAS) clinic. Self-reported methamphetamine use in the last 72 hours was compared to urinalysis, conducted using the immunoassay technique. Sensitivity, negative predictive value (NPV), Cohen's kappa statistics, percent agreement, and positive percent agreement were estimated. Results: Only 24.6% of participants reported methamphetamine use during treatment. Self-reported methamphetamine use had a sensitivity of 50.0% and a NPV of 86.0%. The percent agreement, positive percent agreement, and Cohen's kappa statistic between self-reported use and the urine test were 86.0%, 42.8%, and 52.4%, respectively. No significant factors were found to be associated with the agreement between self-reported use and the urine test. Conclusions: The validity of self-reported methamphetamine use appears to be relatively acceptable and can be used with caution for monitoring treatment.