TOP 44 - Medicaid expansion and post-transplant survival in pediatric heart transplant recipients

Publication Number: 4747.TOP 44

Holly P. Shifman, Boston Children's Hospital, Boston, MA, United States; Elizabeth Blume, Boston Children's Hospital, Boston, MA, United States; Kimberlee Gauvreau, Boston Children's Hospital, Boston, MA, United States; Tajinder P. Singh, Boston Children's Hospital, Boston, MA, United States

Background: Previous studies have demonstrated racial and socioeconomic disparities in post-transplant survival among children undergoing heart transplant. Children from minority backgrounds are more likely to be uninsured or underinsured. Medicaid expansion, part of the Affordable Care Act, was developed to expand access to public insurance, and has been shown to improve post-transplant survival in children undergoing other solid organ transplants.

Objective: To characterize the impact of state Medicaid expansion policies on post-transplant graft survival in pediatric heart transplant recipients.

Design/Methods: Retrospective cohort study of all children ( < 18 years of age) who underwent primary heart transplant in the United States between 2008-2023 using the Organ Procurement and Transplant Network (OPTN) national transplant data. Medicaid expansion status will be determined by recipient home state at transplant and date of expansion implementation for each state. We will use time dependent Cox proportional hazard models to evaluate the association between Medicaid expansion (with varying dates of implementation) and post-transplant graft survival (death/re-transplant) in both the short term ( < 90 days after transplant) and long term (>90 days after transplant), adjusted for recipient and donor clinical variables at transplant. The use of a time dependent analysis will allow us to more accurately characterize the effect of a policy with varying dates of implementation. Sample size is determined by the OPTN database. We anticipate that approximately 6400 patients will meet entry criteria, and that 6100 will not have experienced the primary outcome at 90 days after transplant and therefore be eligible for analysis of the long-term outcome. Although the primary predictor Medicaid expansion is time-varying, we will treat it as fixed for the purposes of this calculation and assume that 70% of patients will undergo transplant in a state with Medicaid expansion at some point during follow-up. With the assumed sample size, we will have 80% power to detect a hazard ratio of 0.84 associated with Medicaid expansion at the 0.05 level of significance. As a sensitivity analysis, we will conduct an interrupted time series analysis of pre- and post-expansion outcomes for the set of states that expanded Medicaid in January 2014 (the first date states were eligible to expand).