Background: Buprenorphine and other medications for opioid use disorder (MOUD) are recommended as standard of care in the treatment of opioid use disorder (OUD) and associated with positive health and addiction-related outcomes.31,32 Although observational research suggests that buprenorphine treatment greater than 12 months yields the greatest benefits,19,34,39 more than 50% of patients discontinue early.40,41 Patients who discontinue face substantially heightened risk of all-cause hospitalization, emergency department visits, opioid overdose and death relative to those who continue treatment,32-34 and most will return to substance use.14 Significance: What explains this high rate of discontinuation has not been well studied.20,21 Prior research, largely utilizing retrospective administrative data, has identified some predictors, including polysubstance use, younger age, minoritized race-ethnicity, male birth sex, higher pain interference and low buprenorphine dose,4,10-11,25 but why or how such factors are linked with early discontinuation remains unknown. Research probing the patient perspective is limited, drawing upon patients in clinical trials or small, homogenous samples. The role of provider or system-level factors in discontinuation remains largely unexplored. Innovation & Impact: Design and methodological innovations of the proposed study include: the national scope of the sample; oversampling rural Veterans, women and Veterans of minoritized race and ethnicity in surveys and interviews, and triangulating patient and provider interviews and survey data to understand areas of convergence and divergence in perceptions regarding discontinuation decisions and treatment encounters. The overall impact of this study is high because it will collect novel data that will identify modifiable factors that inhibit patient retention in treatment, which can be used to develop interventions to improve retention, reduce risk of relapse and improve the overall health and well-being of Veterans with OUD. Specific Aims: Aim 1. Surveys with a national sample of (N=965) Veterans prescribed buprenorphine for OUD paired with administrative data and medical record review will identify modifiable patient-, provider- and system-level factors predictive of buprenorphine discontinuation within 12-months of initiation. Aim 2. Interviews with a national sample of patients (N=40) who recently discontinued buprenorphine and their buprenorphine care provider (N=40) will investigate motivations for discontinuation and perspectives on the process. Methodology: We propose a prospective cohort study utilizing a convergent parallel mixed-methods design to obtain complementary quantitative survey and qualitative interview data. We will enroll a national sample of N=965 Veterans initiating buprenorphine, stratifying sampling to ensure diversity in terms of race, ethnicity, birth sex and rural versus urban residence of patients enrolled. Longitudinal quantitative surveys at baseline, 6 and 12 months will obtain patient-reported data unavailable in administrative records to identify modifiable barriers to treatment retention and learn about patient experiences sustaining versus discontinuing buprenorphine. Administrative data supplemented by medical record review will identify provider and system- level factors associated with early discontinuation. Qualitative interviews with a subset of discontinuing patients, and the clinicians with whom they are paired, will identify motivations for, and experiences with, discontinuation, and contextualize results obtained from survey and medical record review. Next Steps/Implementation: Information obtained through this study will provide a foundation from which to develop interventions targeting patients and providers that address the modifiable causes of early discontinuation.

Buprenorphine and other medications for opioid use disorder are standard of care for the treatment of opioid use disorder, and utilization is linked with substantial reductions in the risk of negative outcomes, including overdose and death. Research has shown that longer periods in treatment (>12 months) yield the greatest benefit, yet more than half of patients will discontinue before 12 months. The goal of this study is to understand why early buprenorphine discontinuation takes place, and identify modifiable factors at the patient, provider and system-level that contribute. Ultimately this study will help to inform interventions designed to improve retention in treatment for Veterans with opioid use disorder.