The Mental Health Parity and Addiction Equity Act Evaluation Study: Some Key Findings

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Speaker: Susan Ettner

Date/Time: October 9, 10 AM – 12 PM

Location: Health Sciences Building (155 College Street, Toronto ON), Room HS 100



Importance: Historically, generosity of insurance benefits for behavioral health (BH) care has lagged behind medical benefits. The federal Mental Health Parity and Addiction Equity Act (MHPAEA), which took effect starting in January 2010, required commercial large-group plans offering BH benefits to match medical benefits in terms of financial requirements and quantitative treatment limits; its Interim Final Rule (IFR), taking effect starting January 2011, added parity in non-quantitative treatment limits (e.g., pre-authorization of services). These provisions went well beyond those of previous federal and state parity laws, potentially having a far greater impact.

Objective: To test whether MHPAEA and its IFR increased BH care penetration rates (the probability of any use) and the level of utilization and expenditures among treated patients.

Design: Individual-level interrupted time series using linked insurance claims, eligibility, plan and employer data from 2008-2013 to estimate segmented regression analyses, allowing for level and slope changes during the transition and post-parity periods. Linear, logistic and gamma regression models are used respectively to estimate the overall impact of parity as well as the impact on penetration rates and levels of use and expenditures among treated patients, controlling for certain patient, plan and employer group characteristics. Generalized Estimating Equations are used to adjust for clustering.

Setting: 6,587 “carve-in” plans administered by Optum, one of the largest managed behavioral health organizations in the country.

Participants: 5,987,776 individuals ages 27-64 (representing 179,506,951 person-months) with behavioral healthcare coverage through large-group, self-insured commercial insurance plans that renew on a calendar-year cycle and are subject to MHPAEA compliance.

Exposure(s): The exposure of interest is time period (pre-parity = 2008-2009; transition period = 2010; post-parity = 2011-2013).

Main Outcome and Measure(s): Total, plan and patient out-of-pocket expenditures on specialty behavioral healthcare; number of outpatient visits (assessment/evaluation, psychotropic medication management, and individual, family, and group psychotherapy); days of intermediate (structured outpatient, day treatment, residential) and inpatient care.

Results: Relative to the pre-parity period, total and plan expenditures increased post-parity due to level changes (by $1.05 and $0.88 PMPM respectively). Assessment/evaluation, individual and group psychotherapy visits increased due to level changes (and in the case of individual psychotherapy, an increase in time trend) but the magnitudes of increases were modest. Structured outpatient care showed a decline in level that was partially offset by an increase in time trend. Both penetration rates and conditional levels of use/expenditures among the treated population contributed to unconditional changes among the full sample.

Conclusions and Relevance: In contrast to most prior parity studies, MHPAEA appears to have some impact among carve-in enrollees, but primarily on total and plan expenditures. These changes may reflect cost-shifting from the patients to the plan rather than increased service use. Enacting a law (and even ensuring compliance) may not change behavior unless consumers are aware of and understand the law. In a recent APA survey, only 4% of Americans knew about MHPAEA and when asked about their BH coverage, many described benefit designs that were incompatible with parity compliance. Patients must also be able to overcome other constraints, such as limited provider supply/poor geographic access, stigma, etc. If the goal of parity legislation is to increase access to care, policymakers might consider additional avenues such as raising awareness and facilitating provider linkages.


Susan L. Ettner is Professor in the Division of General Internal Medicine and Health Services Research in the UCLA Department of Medicine and in the Department of Health Policy and Management in the Fielding UCLA School of Public Health. Dr. Ettner obtained her Ph.D. in Economics at the Massachusetts Institute of Technology in 1991. She was on the faculty of Harvard Medical School in the Department of Health Care Policy prior to joining UCLA in 1999. Dr. Ettner was the 2001 recipient of the Alice S. Hersch New Investigator Award by the Academy for Health Services Research and Health Policy, given each year to the outstanding new health services researcher in the country.

Dr. Ettner’s research interests include mental health and substance abuse services, reciprocity in the relationship between health and labor market outcomes, insurance markets and managed care, chronic disability, post-acute and long-term care. She teaches an advanced research methods course for the doctoral students in the Fielding School of Public Health and is involved in a number of research projects, including a study of the cost-effectiveness of a randomized, integrated patient-provider intervention to prevent harmful and hazardous alcohol use in the elderly; an administrative data analysis of treatment patterns and their relationship to outcomes among managed behavioral health patients; a pilot study of provider financial incentives for improving the quality of depression care; an evaluation of the impact of the Medicare Part D benzodiazepine exclusion on managed care patients with anxiety diagnoses or a history of benzodiazepine use; and an assessment of predictors of health services and long-term care use among triply diagnosed HIV+ patients. Dr. Ettner is also a member of the Task Force and legislative analyst for the California Health Benefits Review Program, which provides independent analyses of the medical, financial, and public health impacts of proposed health insurance benefit mandates.