Cascade of care for office-based buprenorphine treatment in Bronx community clinics

Introduction: The cascade of care for opioid use disorder (OUD) has been described at the population level to inform health policy and in health care systems, programs, and communities to guide targeted interventions. Office-based buprenorphine treatment is essential for expanding access to OUD treatment; however, few studies examine the cascade of care specifically for office-based buprenorphine treatment. Our objective was to describe a cascade of care for patients referred for office-based buprenorphine treatment in the primary care setting. Methods: We conducted a retrospective cohort study of patients with OUD who were referred for office-based buprenorphine treatment within a large, urban health care system between 2018 and 2019. Our primary outcomes included completion of each step of the buprenorphine treatment cascade of care: 1) referred for treatment, 2) scheduled initial visit, 3) completed initial visit, 4) initiated buprenorphine treatment, and 5) retained in treatment at 90 days. We constructed a cascade of care by calculating proportions of patients identified at every step, starting with the total number of patients referred for treatment as the first step. We extracted data from the program's referral database and electronic medical record system. We compared characteristics of patients referred who initiated buprenorphine to those referred who did not initiate buprenorphine treatment using chi-squared tests and t-tests. To account for the hierarchical nature of the data, we conducted a Generalized Estimating Equation (GEE) modeling to test the differences in attrition rates among the steps of the cascade of care. Results: In the 24-month period between 2018 and 2019, 226 patients were referred for office-based buprenorphine treatment at Montefiore's Buprenorphine Treatment Network. Patients' mean age at referral was 47 years, and most were male (68.6%), Hispanic (49.6%), and publicly insured (75.7%). Among all patients, 182 (80.5%) were scheduled for an initial visit, 142 (62.8%) completed the initial visit, 134 (59.3%) initiated buprenorphine treatment, and 95 (42.0%) were retained in treatment at 90 days. 37.2% of all patients referred did not complete the initial visit. A GEE model showed that attrition is significantly steeper in the first two steps of the cascade of care, compared to the later three steps (AOR = 1.95, 95% CI = 1.31–2.91, p < 0.05). Compared to referred patients who did not initiate treatment, those referred who initiated treatment were more likely to be using non–prescribed buprenorphine at time of referral (19.4% vs. 5.4%, p < 0.05) and be self-referred (22.4% vs. 9.8%, p < 0.05). Conclusion: Our study is the first to describe a cascade of care for office-based buprenorphine treatment in a large health care system. The study observed the steepest attrition in the first two steps of the cascade of care, where more than a third of patients referred did not complete the initial visit. Patients who were self-referred, or using non–prescribed buprenorphine were more likely to initiate treatment. A cascade of care specific for office-based buprenorphine can inform future efforts to improve linkage to care.