Affordable Care Act's Medicaid Expansion and Use of Regionalized Surgery at High-Volume Hospitals.

Background: The Affordable Care Act (ACA)'s Medicaid expansion has increased access to surgical care overall. Whether it was associated with reduced disparities in use of regionalized surgery at high-volume hospitals (HVH) remains unknown. Quasi-experimental evaluations of this expansion were performed to examine the use of regionalized surgery at HVH among racial/ethnic minorities and low-income populations.

Study Design: Data from State Inpatient Databases (2012 to 2014), the American Hospital Association Annual Survey Database, and the Area Resource File from Health Resources and Services Administration, were used to examine 166,558 nonelderly (ages 18 to 64) adults at 468 hospitals, who underwent 1 of 4 regionalized surgical procedures in 3 expansion (KY, MD, NJ) and 2 nonexpansion states (NC, FL). Thresholds of HVH were defined using the top quintile of visits per year. Interrupted time series were performed to measure the impact of expansion on use rates of regionalized surgery at HVH overall, by race/ethnicity, and by income.

Results: Overall, ACA's expansion was not associated with accelerated use rates of regionalized surgical procedures at HVH (odds ratio [OR] 1.016, p = 0.297). Disparities in use of regionalized surgical procedures at HVH among ethnic/racial minorities and low-income populations were unchanged; minority vs white (OR 1.034 p = 0.100); low-income vs high-income (OR 1.034, p = 0.122).

Conclusions: Early findings from ACA's Medicaid expansion revealed no impact on the use rates of regionalized surgery at HVH overall or on disparities among vulnerable populations. Although these results need ongoing evaluation, they highlight potential limitations in ACA's expansion in reducing disparities in use of regionalized surgical care.