Affordable Care Act Medicaid expansion associated with increased liver transplant waitlist access without worsening mortality

It is unclear what impact Affordable Care Act (ACA) Medicaid expansion has had on the liver transplantation (LT) waitlist. We aimed to assess associations between ACA Medicaid expansion and LT waitlist outcomes. The United Network for Organ Sharing Standard Transplant Analysis and Research (UNOS STAR) database was queried for patients listed for LT between January 1, 2009, and December 31, 2018. Our primary outcome was waitlist mortality and our secondary outcomes included Medicaid use on the LT waitlist and transplant rate. States were divided into groups based on their expansion status and the study period was divided into 2 time intervals - pre-expansion and post-expansion. Difference-in-difference (DiD) models were created to assess the impacts of expansion on each of the outcomes and for racial/ethnic and sex groups. In total, 56,414 patients from expansion states and 32,447 patients from nonexpansion states were included. Three-year waitlist mortality decreased at a similar rate in both cohorts [DiD estimate: 0.1, (95% CI, -1.1, -1.4), p = 0.838], but Medicaid use increased [DiD estimate: +7.7, (95% CI, 6.7, 8.7), p < 0.001] to a greater degree in expansion states after expansion than nonexpansion states. Between the 2 time intervals, Medicaid use on the LT waitlist increased from 19.4% to 26.1% in expansion states but decreased from 13.4% to 12.1% in nonexpansion states. In patients on Medicaid, there was a slight increase in the 3-year transplant rate associated with Medicaid expansion [DiD estimate +5.0, (95% CI, 1.8, 8.3), p = 0.002], which may in part be explained by differences in patient characteristics. Medicaid expansion was associated with increased Medicaid use on the LT waitlist without worsening overall waitlist mortality or transplant rate, suggesting that lenient and widespread public health insurance may increase access to the LT waitlist without adversely affecting outcomes.