Improvement in physical and mental health attributable to the affordable care act.

Introduction: The Affordable Care Act (ACA) represents the most comprehensive U.S. health reform since Medicare and Medicaid. However, evidence on its impact on population health in the general U.S. population, particularly mental health, remains limited. Methods: We analyzed a nationally representative sample of non-elderly adults aged 18-64 from the Medical Expenditure Panel Survey (2007-2019). Outcomes included two health-related quality of life (HRQOL) measures derived from the SF-12 v2: physical component summary (PCS) and mental component summary (MCS) scores. Using conditional-mean and quantile-regression difference-in-differences models, we examined the effect of the ACA by comparing pre-post changes in PCS and MCS scores among non-elderly adults relative to counterfactuals from TRICARE beneficiaries not subject to ACA provisions. Results: Our conditional-mean DID estimates indicate that the ACA was associated with a 2.7% increase in PCS scores among non-elderly adults during 2011-2013. Although statistically insignificant, MCS scores exhibited increases of growing magnitude following the implementation of the major ACA major provisions in 2014. Notably, simultaneous-quantile DID estimates suggest that the increases in PCS and MCS scores attributable to the ACA were concentrated among individuals with relatively lower health levels, particularly those around the 30th to 60th percentiles of the score distributions. Discussion: Findings indicate that the ACA led to measurable gains in physical and mental health, particularly among relatively lower-middle levels of physical and mental health. Policymakers assessing the value of the ACA, or more generally debating the value of expanding access to health insurance in the population, should consider these positive gains in population health.