Do Urine Drug Tests Reveal Substance Misuse Among Patients Prescribed Opioids for Chronic Pain?

Background: Urine drug testing (UDT) is a recommended risk mitigation strategy for patients prescribed opioids for chronic pain, but evidence that UDT supports identification of substance misuse is limited.

Objective: Identify the prevalence of UDT results that may identify substance misuse, including diversion, among patients prescribed opioids for chronic pain.

Design: Retrospective cohort study.

Subjects: Patients (n=638) receiving opioids for chronic pain who had one or more UDTs, examining up to eight substances per sample, during a one 1-year period.

Main Measures: Experts adjudicated the clinical concern that UDT results suggest substance misuse or diversion as not concerning, uncertain, or concerning.

Key Results: Of 638 patients, 48% were female and 49% were over age 55 years. Patients had a median of three UDTs during the intervention year. We identified 37% of patients (235/638) with ≥1 concerning UDT and a further 35% (222/638) having ≥1 uncertain UDT. We found concerning UDTs due to non-detection of a prescribed substance in 24% (156/638) of patients and detection of a non-prescribed substance in 23% (147/638). Compared to patients over 65 years, those aged 18-34 years were more likely to have concerning UDT results with an adjusted odds ratio (AOR) of 4.8 (95% confidence interval [CI] 1.9-12.5). Patients with mental health diagnoses (AOR 1.6 [95% CI 1.1-2.3]) and substance use diagnoses (AOR 2.3 [95% CI 1.5-3.7]) were more likely to have a concerning UDT result.

Conclusions: Expert adjudication of UDT results identified clinical concern for substance misuse in 37% of patients receiving opioids for chronic pain. Further research is needed to determine if UDTs impact clinical practice or patient-related outcomes.