Buprenorphine prescriber monthly patient caseloads: An examination of 6-year trajectories

Background: Many active buprenorphine prescribers treat few patients monthly, but little information is available regarding how prescribers’ buprenorphine caseload fluctuates over time or how long it takes new prescribers to reach higher patient caseloads. We examine buprenorphine-prescribing clinicians’ patient caseloads over time and explore prescriber characteristics associated with different caseload trajectories. Methods: Using 2006–2018 national buprenorphine pharmacy claims, we calculate monthly patient caseloads for buprenorphine prescribers for 6 years following a clinician's first filled buprenorphine prescription. We use K-means clustering to identify clusters of clinician caseload trajectories and bivariate analyses to examine prescriber and county characteristics associated with different trajectory classes. Results: We identified 42,067 buprenorphine prescribers with 3 trajectory classes. High-volume (1.4%;n = 571) whose mean monthly patient caseload increased to approximately 40 patients through the initial 20 months and stabilized at 40 or more patients; moderate-volume (9.2%;n = 3891) whose mean patient caseload increased during the initial 20 months, stabilizing at 15–20 patients; and low-volume (89.4%;n = 37,605), who typically had fewer than 5 patients monthly. Most low-volume prescribers (n = 31,470; 83.7% of all prescribers) initially treated 1–2 patients for several months, followed by no subsequent prescribing. Conclusion: Almost three-quarters of buprenorphine prescribers treated no more than a few patients for several months before ceasing buprenorphine prescribing; only 10% of prescribers averaged more than 10 patients per month over the next 6 years. Efforts are needed to identify factors contributing to prescribers being willing to continue prescribing buprenorphine over time and to prescribe to more patients in order to increase access to buprenorphine treatment.