Implementation of an office-based addiction treatment model for Medicaid enrollees: A mixed methods study.

Introduction: Medications for opioid use disorder (MOUD) are the most effective treatment for opioid use disorder (OUD) but remain underutilized. To reduce barriers to MOUD prescribing and increase treatment access, New Jersey's Medicaid program implemented the Office-Based Addiction Treatment (OBAT) Program in 2019, which increased reimbursement for office-based buprenorphine prescribing and established newly reimbursable patient navigation services in OBAT clinics. Using a mixed-methods design, this study aimed to describe stakeholder experiences with the OBAT program and to assess implementation and uptake of the program.

Methods: This study used a concurrent, triangulated mixed-methods design, which integrated complementary qualitative (semi-structured interviews) and quantitative (Medicaid claims) data to gain an in-depth understanding of the implementation of the OBAT program. We elicited stakeholder perspectives through interviews with 22 NJ Medicaid MOUD providers and 8 policy key informants, and examined trends in OBAT program utilization using 2019-2020 NJ Medicaid claims for 5380 Medicaid enrollees who used OBAT services. We used cross-case analysis (provider interviews) and a case study approach (key informant interviews) in analyzing qualitative data, and calculated descriptive statistics and trends for quantitative data.

Results: Provider enrollment and utilization of OBAT services increased steadily during the first two years of program implementation. Interviewees reported that enhanced reimbursements for office-based MOUD incentivized greater MOUD prescribing, while coverage of patient navigation services improved patient care. Despite increasing enrollment in the OBAT program, the proportion of primary care physicians in the state who enrolled in the program remained limited. Key barriers to enrollment included: requirements for a patient navigator; concerns about administrative burdens and reimbursement delays from Medicaid; lack of awareness of the program; and beliefs that patients with OUD were better served in comprehensive care settings. Patient navigation was highlighted as a critical and valuable element of the program, but navigator enrollment and reimbursement challenges may have prevented greater uptake of this service.

Conclusions: Implementation of an OBAT model that enhanced reimbursement and provided coverage for patient navigation likely expanded access to MOUD in NJ. Results support initiatives like the OBAT program in improving access to MOUD, but program adaptations, where feasible, could improve uptake and utilization.