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.