Longitudinal Trajectories of OUD Care following Initial Engagement with a Low-Threshold Bridge Clinic - Opioid use disorder (OUD) continues to represent a major public health crisis contributing to significant rates of overdoserelated death each year. Yet, only 18% of adults with OUD received evidence-based treatment in 2023. Medication for OUD (MOUD) is a highly efficacious pharmacological approach shown to reduce risk of overdose and other adverse health-related outcomes. Of the three FDA-approved MOUDs, buprenorphine has grown in popularity due to its safety profile and flexible administration in outpatient settings. Despite its efficacy and availability, buprenorphine is significantly underutilized due to multi-level barriers such as inadequate program capacity, long wait times, and lack of support during high-risk transitions (e.g., hospital discharge, release from incarceration). To address this, low threshold Bridge Clinics have been established across the US in general medical settings to provide rapid access to buprenorphine. A growing body of literature supports the utility of Bridge Clinics in increasing initial access to buprenorphine, however, there have been no prospectively designed longitudinal studies investigating buprenorphine adherence across time, nor the factors that impact adherence and retention, following initial engagement with a Bridge Clinic model. The overarching goal of this R01 is to leverage a large-scale, multisite investigation, employing a prospective longitudinal naturalistic design, to characterize fine-grain dynamic patterns of buprenorphine adherence, substance use and symptoms, and psychosocial factors among a cohort (N=1,000) of adults initiating OUD treatment at three Bridge Clinics across two large healthcare systems. These variables will be assessed via 3 months of incentivized daily text diaries and surveys at baseline, 6, 9 and 12 months to address the following specific aims:1) Describe day-to-day variability and longitudinal trajectories of buprenorphine adherence, substance use and symptoms, and psychosocial factors via daily text diaries across 3 months, 2) determine which day-to-day trajectories estimated in Aim 1 best predict OUD-related outcomes including linkage to longer term care and health care utilization at 12 months post Bridge Clinic intake. The primary outcome is the number of days to buprenorphine discontinuation objectively verified via state prescription drug monitoring logs, and, 3) explore baseline factors that moderate the effects of day-to-day patterns on OUD-related outcomes using a machine-learning approach. This investigation is the longest, and most comprehensive study of its kind, assessing fine-grained and dynamic patterns of behavior following initial engagement with a low threshold Bridge Clinic, including factors which impact buprenorphine adherence, connection to longer term addiction care, and overdose risk. This is a critical step in understanding how, and for whom, these innovative treatment models may reduce risks associated with OUD, and for identifying modifiable factors for future intervention efforts.
