Buprenorphine Utilization and Prescribing Among New Jersey Medicaid Beneficiaries After Adoption of Initiatives Designed to Improve Treatment Access.

Importance: Buprenorphine is underutilized as a treatment for opioid use disorder (OUD); state policies may improve buprenorphine access and utilization. Objective: To assess buprenorphine prescribing trends following New Jersey Medicaid initiatives designed to improve access. Design, Setting, and Participants: This cross-sectional interrupted time series analysis included New Jersey Medicaid beneficiaries who were prescribed buprenorphine and had 12 months continuous Medicaid enrollment, OUD diagnosis, and no Medicare dual eligibility, as well as physician or advanced practitioners who prescribed buprenorphine to Medicaid beneficiaries. The study used Medicaid claims data from 2017 to 2021. Exposure: Implementation of New Jersey Medicaid initiatives in 2019 that removed prior authorizations, increased reimbursement for office-based OUD treatment, and established regional Centers of Excellence. Main Outcomes and Measures: Rate of buprenorphine receipt per 1000 beneficiaries with OUD; percentage of new buprenorphine episodes lasting at least 180 days; buprenorphine prescribing rate per 1000 Medicaid prescribers, overall and by specialty. Results: Of 101 423 Medicaid beneficiaries (mean [SD] age, 41.0 [11.6] years; 54 726 [54.0%] male; 30 071 [29.6%] Black, 10 143 [10.0%] Hispanic, and 51 238 [50.5%] White), 20 090 filled at least 1 prescription for buprenorphine from 1788 prescribers. Policy implementation was associated with an inflection point in buprenorphine prescribing trend; after implementation, the trend increased by 36%, from 1.29 (95% CI, 1.02-1.56) prescriptions per 1000 beneficiaries with OUD to 1.76 (95% CI, 1.46-2.06) prescriptions per 1000 beneficiaries with OUD. Among beneficiaries with new buprenorphine episodes, the percentage retained for at least 180 days was stable before and after initiatives were implemented. The initiatives were associated with an increase in the growth rate of buprenorphine prescribers (0.43 per 1000 prescribers; 95% CI, 0.34 to 0.51 per 1000 prescribers). Trends were similar across specialties, but increases were most pronounced among primary care and emergency medicine physicians (eg, primary care: 0.42 per 1000 prescribers; 95% CI, 0.32-0.53 per 1000 prescribers). Advanced practitioners accounted for a growing percentage of buprenorphine prescribers, with a monthly increase of 0.42 per 1000 prescribers (95% CI, 0.32-0.52 per 1000 prescribers). A secondary analysis to test for changes associated with non-state-specific secular trends in prescribing found that quarterly trends in buprenorphine prescriptions increased in New Jersey relative to all other states following initiative implementation. Conclusions and Relevance: In this cross-sectional study of state-level New Jersey Medicaid initiatives designed to expand buprenorphine access, implementation was associated with an upward trend in buprenorphine prescribing and receipt. No change was observed in the percentage of new buprenorphine treatment episodes lasting 180 or more days, indicating that retention remains a challenge. Findings support implementation of similar initiatives but highlight the need for efforts to support long-term retention.