The impact of peer support in treatment engagement and adverse events for Medicaid beneficiaries with substance use disorder: a mixed-methods study - PROJECT SUMMARY/ABSTRACT Substance use disorder (SUD) due to drugs other than alcohol, which affects 9% of adults in the United States, is a significant public health concern contributing to substantial morbidity and mortality, resulting in over 100,000 overdoses in 2022 alone. While effective SUD treatment exists, fewer than 25% of people with SUD receive treatment. Peer support services (PSS) offer a potential avenue for enhancing SUD treatment and outcomes, with the goal of helping people with SUD initiate and remain engaged in the recovery process. These services, delivered by trained and credentialed peer specialists who have firsthand experience with SUD, encompass a wide range of support services, including recovery planning, community linkages, and social and emotional support services. PSS are unique to other types of care navigation in that they emphasize improving clients' psychosocial skills, including resilience, coping, and empowerment. PSS, which use a recovery coaching model, are also distinct from the peer support provided by uncredentialed sponsors in 12- step facilitation. Growing adoption of PSS has outpaced the evidence on the effectiveness of PSS, which is limited and mixed. Nowhere is this more evident than with Medicaid, the largest payer of SUD treatment services in the U.S. Medicaid is an innovator in coverage of PSS. In 2024, 41 state Medicaid programs covered PSS for adults with SUD, increasing from only 26 states in 2017. Medicaid's substantial expansion of PSS coverage and the urgent need for SUD treatment services within the Medicaid population creates an opportunity to rigorously evaluate the impact of receiving PSS on SUD treatment and SUD-related adverse outcomes. Furthermore, the COVID-era Medicaid policy changes that expanded telehealth coverage provide an avenue to compare the effectiveness of telehealth PSS relative to in-person delivered PSS. The overall goals of this study are to provide robust evidence on whether and how PSS impact SUD treatment engagement and outcomes and to inform the design of PSS coverage policy in Medicaid and other insurance programs. We will focus on the following specific aims to achieve these objectives: (1) Assess the impact of Medicaid-covered PSS on SUD treatment initiation, engagement, and retention among Medicaid beneficiaries with SUD, (2) Assess the impact of Medicaid PSS on adverse events including SUD-related emergency department visits, unplanned inpatient readmissions, and drug overdose among Medicaid beneficiaries with SUD; and (3) Characterize how Medicaid PSS coverage policies can influence PSS implementation for Medicaid beneficiaries with SUD. This proposed mixed-methods study will use a concurrent-embedded approach, such that quantitative results (Aims 1-2) will inform qualitative analyses (Aim 3) and vice versa at various points in the study. Study findings will build evidence on the impact of PSS on SUD treatment and overdose and inform the rapidly evolving landscape of PSS policy and implementation.
