Prescribing Characteristics Associated With Opioid Overdose Following Buprenorphine Taper.

Importance: Retention in buprenorphine therapy is associated with a lower risk of opioid overdose. Nevertheless, many patients discontinue treatment, and there is limited evidence to guide buprenorphine tapering. Objective: To understand what prescribing characteristics are associated with opioid overdose following buprenorphine taper. Design, Setting, and Participants: This is a population-based, retrospective, cohort study of adults who were maintained on buprenorphine for at least 60 days and underwent a buprenorphine taper. The study was conducted in the Canadian province of Ontario, using linked administrative health data. New buprenorphine treatment episodes were accrued between January 1, 2013, and January 1, 2019, and the maximum follow-up was April 30, 2020. Data analysis was performed from December 2020 to August 2022. Exposures: The primary exposure of interest was time to taper initiation (≤1 year vs >1 year). Secondary exposures included mean rate of taper, percentage days during which the dose was decreasing, and taper duration. Main Outcomes and Measures: The primary outcome measure was time to fatal or nonfatal opioid overdose within 18 months following treatment discontinuation. Results: Among 5774 individuals, the median (IQR) age at index date was 34 (28-44) years, and 3462 individuals (60.0%) were male. Time to taper initiation longer than 1 year vs 1 year or less (6.73 vs 10.35 overdoses per 100 person-years; adjusted hazard ratio [aHR], 0.69; 95% CI, 0.48-0.997), a lower mean rate of taper (≤2 mg per month, 6.95 overdoses per 100 person-years; >2 to ≤4 mg per month, 11.48 overdoses per 100 person-years; >4 mg per month, 17.27 overdoses per 100 person-years; ≤2 mg per month vs >4 mg per month, aHR, 0.65; 95% CI, 0.46-0.91; >2 to ≤4 mg per month vs >4 mg per month, aHR, 0.69; 95% CI, 0.51-0.93), and dose decreases in 1.75% or less of days vs more than 3.50% of days during the taper period (5.87 vs 13.87 overdoses per 100 person-years; aHR, 0.64; 95% CI, 0.43-0.93) were associated with reduced risk of opioid overdose; however, taper duration was not. Conclusions and Relevance: In this retrospective cohort study, buprenorphine tapers undertaken after at least 1 year of therapy, a slower rate of taper, and a lower percentage of days during which the dose was decreasing were associated with a significantly lower risk of opioid overdose, regardless of taper duration. These findings underscore the importance of a carefully planned taper and could contribute to reduction in opioid-related overdose death.