Since opioid-use disorder is a serious health condition for which buprenorphine is proven effective but is underused by providers, this article presents two approaches to measuring treatment duration, factors associated with retention, and patterns of care.
The study determined incident buprenorphine prescribing for all Washingtonians, using prescription monitoring program data from 2012 to 2019. The study calculated episode of care and cumulative time in care. Generalized linear models estimated associations among the length of the first episode of care and cumulative time in care with sex, age, and rurality. Cox proportional hazards models estimated the time to discontinuing buprenorphine for the first four episodes of care and time to discontinuing the last episode of care. Mean and median duration of the first episode were 320 and 84 days, respectively, and for cumulative time in care, 308 and 195 days. A minority of peoples' first episodes exceeded 180 days (37 percent). Being female and older were significantly associated with longer first episodes and cumulative time in care. Survival analyses indicated that the proportion of those still in care at 6, 12, and 24 months into their first episode of care declined for those with more than one episode of care; conversely, the study found much smaller differences in retention for the last episode of care, indicating that many people were eventually able to be retained in care for longer periods of time. (publisher abstract modified)