The Mental Health Parity and Addiction Equity Act Evaluation Study: Impact on Specialty Behavioral Health Care Utilization and Spending Among Carve-In Enrollees.

OBJECTIVE: The federal Mental Health Parity and Addiction Equity Act (MHPAEA) sought to eliminate historical disparities between insurance coverage for behavioral health (BH) treatment and coverage for medical treatment. Our objective was to evaluate MHPAEA's impact on BH expenditures and utilization among "carve-in" enrollees.

METHODS: We received specialty BH insurance claims and eligibility data from Optum, sampling 5,987,776 adults enrolled in self-insured plans from large employers. An interrupted time series study design with segmented regression analysis estimated monthly time trends of per-member spending and use before (2008-2009), during (2010), and after (2011-2013) MHPAEA compliance (N=179,506,951 member-month observations). Outcomes included: total, plan, patient out-of-pocket spending; outpatient utilization (assessment/diagnostic evaluation visits, medication management, individual and family psychotherapy); intermediate care utilization (structured outpatient, day treatment, residential); and inpatient utilization.

RESULTS: MHPAEA was associated with increases in monthly per-member total spending, plan spending, assessment/diagnostic evaluation visits [respective immediate increases of: $1.05 (P=0.02); $0.88 (P=0.04); 0.00045 visits (P=0.00)], and individual psychotherapy visits [immediate increase of 0.00578 visits (P=0.00) and additional increases of 0.00017 visits/mo (P=0.03)].

CONCLUSIONS: MHPAEA was associated with modest increases in total and plan spending and outpatient utilization; for example, in July 2012 predicted per-enrollee plan spending was $4.92 without MHPAEA and $6.14 with MHPAEA. Efforts should focus on understanding how other barriers to BH care unaddressed by MHPAEA may affect access/utilization. Future research should evaluate effects produced by the Affordable Care Act's inclusion of BH care as an essential health benefit and expansion of MHPAEA protections to the individual and small group markets.