The Impact of Medicaid Expansion on Living Donor Kidney Transplantation in the U.S

End-stage renal disease (ESRD) is the final stage of chronic kidney disease (CKD), an illness which affected over 725,000 patients in the US in 2016. Living donor kidney transplant (LDKTx) is the preferred treatment for patients with ESRD but continues to be significantly less common than deceased donor kidney transplant. Individuals with lower SES and minorities tend to have worse access to healthcare and to be less knowledgeable about ESRD and their various treatment options, including LDKTx. The Affordable Care Act intended to expand Medicaid to cover a larger range of individuals than had been previously covered and, as of 2016, 33 states had expanded Medicaid. In this study, we describe variation in LDKTx rates and estimate the impact that Medicaid expansion had on patients’ likelihood of receiving a LDKTx.

We use United Network for Organ Sharing data from January 2008 through December 2016. The outcome of interest was receipt of a LDKTx among waitlisted patients and the exposure was Medicaid expansion. We examine LDKTx rates at the transplant center level, both describing the extent of variation and using OLS to examine what transplant center-level factors may drive such variation. We use difference-in-difference analysis to estimate the impact of Medicaid Expansion on LDKTx rates at the state level, comparing states based on expansion status. Finally, our main analysis examines the impact of Medicaid expansion on the likelihood of LDKTx.

Expansion intended to increase access to care for disadvantaged individuals which may not necessarily lead to an increase in living donor kidney transplant rates. In fact, we find that expansion is associated with a decrease in the likelihood of LDKTx within the first year of 2.3 percentage points (p<0.001). The percentage of waitlisted patients at a given center that were black was negatively associated with LDKTx rates (p<0.001). In analyses between states, we find comparing Early and Late expansion to Never expansion states after Medicare expansion showed a decline in LDKTx rates (~ 0.2% and ~0.3% respectively) relative to Never expansion states. The distribution of LDKTx rates suggests that while most centers performed relatively low rates of LDKTx, some centers vastly outperform others (0-19.3% of waitlisted patients in 2016).

Medicaid expansion has changed the health insurance landscape across the country and it is important to understand the impact that is has had on kidney transplantation. LDKTx is the preferred treatment for ESRD patients and our results suggest that increased insurance coverage is not enough to improve access to this life-saving treatment for low SES individuals in the US. The large amount of variation seen across transplant centers is a cause for concern when we consider the goal of equitable treatment for patients across the nation. However, such variation also serves as a reminder that there remains much room for improvement in the treatment of ESRD patients. This is an issue that is likely to increase in importance as our end-stage renal disease population continues to grow by around 20,000 individuals per year.