Impact of the Medicare Shared Savings Program on utilization of mental health and substance use services by eligibility and race/ethnicity

OBJECTIVE: To assess the impact of the Medicare Shared Savings Program (MSSP) ACOs on mental health and substance use services utilization and racial/ethnic disparities in care for these conditions. DATA SOURCES: Five percent random sample of Medicare claims from 2009 to 2016. STUDY DESIGN: We compared Medicare beneficiaries in MSSP ACOs to non‐MSSP beneficiaries, stratifying analyses by Medicare eligibility (disability vs age 65+). We estimated difference‐in‐difference models of MSSP ACOs on mental health and substance use visits (outpatient and inpatient), medication fills, and adequate care for depression adjusting for age, sex, race/ethnicity, region, and chronic medical and behavioral health conditions. To examine the differential impact of MSSP on our outcomes by race/ethnicity, we used a difference‐in‐difference‐in‐differences (DDD) design. DATA COLLECTION/EXTRACTION METHODS: Not applicable. PRINCIPAL FINDINGS: MSSP ACOs were associated with small reductions in outpatient mental health (Coeff: −0.012, P