Medicaid Expansion and 30-Day Mortality After Heart Failure Hospitalization: A Nationwide Study

Medicaid Expansion (ME) under the Affordable Care Act sought to improve health access though not all states expanded Medicaid. Our goal is to examine whether ME impacts 30-day post-discharge mortality rates for heart failure (HF) hospitalizations.

We constructed a data set incorporating 30-day HF mortality and hospital service area (HSA) characteristics using five sources: (1) Centers for Medicare and Medicaid Services, (2) Medicaid Budget and Expenditure System, (3) US Census Bureau, (4) Dartmouth Atlas of Healthcare, (5) Kaiser Family Foundation. We categorized states as expanding Medicaid by 2014 or not expanding until 2020, excluding five states that expanded between 2014 and 2020. A difference-in-difference (DID) model, adjusted for hospital and HSA factors, was used for analysis.

Among 3839 hospitals, 52% were in ME states. Before 2014, 30-day mortality rates were higher in non-ME state hospitals than in ME state hospitals (11.6% vs. 11.4%; p < 0.001). After 2014, rates increased in non-ME state hospitals (change = 0.11%, 95% CI: 0.04% to 0.18%) but remained unchanged in ME state hospitals (change = 0.01%, 95% CI: -0.07% to 0.08%). The adjusted DID analysis showed a significant disparity in trends between ME and non-ME states (adjusted DID: -0.11%, 95% CI: -0.21% to -0.02%; p = 0.02). A dose-response relationship revealed that each increase of 10,000 new Medicaid enrollees was associated with 0.002% (95% CI: -0.003 to -0.001; p < 0.001) reduced 30-day HF mortality.

Hospitals in ME states maintained stable mortality rates, contrasting with increases in non-ME states, suggesting that improved healthcare access through ME contributed to better outcomes.