Abstract
Background: Medicaid expansion (ME) under the Affordable Care Act has reduced the number of uninsured patients, although its preferential effects on vulnerable populations have been mixed. This study examined whether ME preferentially improved cardiac surgery use by insurance strata, race, and income level. Methods: Non-elderly adults (aged 18-64 years) who underwent coronary artery bypass grafting, aortic valve replacement, mitral valve replacement, or mitral valve repair were identified in the State Inpatient Databases for 3 expansion states (Kentucky, New Jersey, and Maryland) and 2 non-expansion states (North Carolina and Florida) from 2012 to the third quarter of 2015. We used adjusted Poisson interrupted time series to determine the impact of ME on cardiac surgery use for Medicaid or uninsured (MCD/UIS) patients, racial and ethnic minorities, and individuals from low-income areas. Results: In expansion states, use among non-White MCD/UIS patients had a positive trend after ME (2.3%/quarter; P = .156), whereas use for White MCD/UIS patients fell (–1.7%/quarter; P = .117). In contrast, use among non-White MCD/UIS in non-expansion states decreased by 4.4% (P < .001) which was a greater decline than among White MCD/UIS patients (–1.8%/quarter; P = .057). There was no substantial effect of ME on cardiac surgery use for MCD/UIS patients from low- versus high-income areas. Conclusions: These findings demonstrate that the use of cardiac surgical procedures was generally unchanged after ME; however, nonsignificant trend differences suggest a narrowing gap between vulnerable and non-vulnerable groups in ME states. These preliminary findings help describe the association of insurance coverage as a driver of cardiac surgery use among vulnerable patients. © 2021 The Society of Thoracic Surgeons