Utility of Urine Drug Testing in Outpatient Addiction Evaluations.

OBJECTIVE: Data examining usefulness of urine drug testing in addiction settings for accurately establishing diagnoses and informing treatment is limited. In this retrospective-cohort study we examined the utility of performing urine drug testing in patients presenting for an outpatient addiction assessment.

METHODS: Urine drug testing and patient-reported substance use history were obtained from the medical record of patients who presented for an outpatient addiction evaluation. Patients who denied use of a substance within the window of detection but tested positive were considered to have misrepresented their use. Differences between patients accurately representing versus misrepresenting their use were evaluated. Sensitivity/specificity of drug tests were calculated from self-report and changes to treatment recommendations and diagnoses assessed.

RESULTS: One hundred and seventy-four patients (mean age = 43.35 ± 15.68 years) were included and the sample was majority male (67%). Ninety-four (54%) patients reported use of a substance within the window of detection. Of 80 patients denying recent use, 14 tested positive (8%). There were no differences in sex (P = 0.78) or age (P = 0.12); referral sources differed significantly between correct and incorrect responders (P = 0.01). Specificity varied between 96% and 99%, while sensitivity had a wider range (17%-87%). Treatment recommendations and diagnoses were altered after review of drug testing results in 1 patient (0.5%). However, in the remainder, all patients were already diagnosed with a severe substance use disorder and had received recommendations to initiate residential/outpatient substance use treatment.

CONCLUSIONS: Among patients completing urine drug testing during outpatient substance use disorder evaluation positive screens alerted providers to undisclosed persistent substance use and potential withdrawal in 8% of the cohort and resulted in a change in diagnoses and/or treatment in 1 patient.