Weekly Drug Testing is Associated With Modestly Improved Treatment Retention Among People Receiving Medications for Opioid Use Disorder

Urine drug testing (UDT) is routinely used alongside the provision of medications for opioid use disorder (MOUD) to monitor for nonmedical use of other substances and diversion. However, there is little evidence to guide us on how frequently to use this test. Researchers in British Columbia, Canada used data from a cohort of 30,898 adults with OUD who initiated methadone or buprenorphine to investigate the association of UDT frequency with MOUD retention and all-cause mortality.

• The study included 18,988 individuals who started methadone, and 11,910 who started buprenorphine; approximately 40 percent of all patients discontinued MOUD within one month of initiation.
• Weekly UDT was associated with a 5 percent decrease in the risk of MOUD discontinuation in the first year of treatment when compared with no testing. There was no significant difference in risk of MOUD discontinuation between less frequent and no testing.
• There was no significant association between UDT frequency and mortality.

Comments: This study suggests that UDT does not have a large impact on MOUD retention or mortality; it cannot tell us if it mitigates diversion. The modest improvement in retention with weekly UDT could be due to the information that UDT provides, or simply because these patients may have had more frequent contact with care. It should be noted that in British Columbia, methadone and buprenorphine are prescribed through primary care and dispensed at pharmacies; these findings may not apply to other settings.

Darius A. Rastegar, MD

Reference: Kurz M, Guerra-Alejos BC, Min JE, et al. Comparative effectiveness of urine drug testing scheduled alongside opioid agonist treatment; emulation of a population-based target trial in British Columbia, Canada. Addiction. 2025;120(12):2435–2447.