Patient and Prescriber characteristics associated with return to daily-dispense methadone: A multilevel cohort study

Early in the SARS-Cov-2 pandemic, modified clinical guidance recommended the provision of take-home methadone doses for those previously ineligible to facilitate social distancing. Following this change, studies reported improved treatment retention among patients granted expanded access to take-home doses. However, most patients resumed daily dispensed methadone within six months. Factors associated with the return to daily dispensed methadone remain unknown. Therefore, we conducted a population-based cohort study to identify patient and prescriber-related characteristics associated with return to daily dispensed methadone. Our study included all residents of Ontario, Canada who received daily dispensed methadone on March 21, 2020, and were then provided at least one take-home dose between March 22, 2020, and April 21, 2020. Follow-up time was divided into 14-day discrete time intervals. The primary outcome was return to daily dispensed methadone, defined as the first interval where a take-home dose was not dispensed. A multilevel discrete time survival model with a complementary log-log link function and random intercepts across prescribers to account for patient clustering by prescriber was used to approximate cause-specific hazard ratios. Within 26 weeks, 1,675 (58.5%) individuals were reverted to daily dispensed methadone. Person-level variables significantly associated with our primary outcome included occurrence of an emergency department visit during or before the interval of interest (HR = 1.27; 95% CI = 1.05, 1.55) and missed methadone dose(s) in the interval prior (HR = 1.59; 95% CI = 1.44, 1.76). Lastly, patients prescribed methadone by a high-volume (top 20th percentile) opioid agonist treatment prescriber had an increased hazard of return to daily dispensed methadone compared to those prescribed methadone by a low-volume (50th percentile) prescriber (HR = 1.44; 95% CI = 1.14, 1.83). While patient characteristics that may indicate clinical instability, such as recent history of missed methadone dose(s) were associated with return to daily dispensed methadone, prescriber OAT client volume was also be associated this outcome.