Medicaid expansion and the mechanics of increased access to organ transplantation

Abstract: Medicaid expansion’s effect on coverage and access are well documented in many health care domains. The extent to which coverage leads to access depends on system, patient, and disease and treatment-specific factors. In this paper, we explore several dimensions of Medicaid expansion on the unique ecosystem surrounding organ transplantation. We use a difference-in-differences design, harnessing within-state variation over time to measure the effect of coverage expansion on a set of access measurements that disentangle different mechanisms through which increased coverage impacted access. We compute the outcomes by dividing the number of Medicaid transplant candidates added to the waiting list (1) by the population in each state, to measure the impact of increased ability to afford care, (2) by the total of Medicaid enrollees in the state, to measure the impact of increased disease detection and (3) by all payers waiting-list additions, measuring crowding out of other forms of health insurance. Using data on the universe of organ donors and transplant candidates, from the Organ Procurement and Transplantation Network, we find Medicaid expansion to result in 10.6% increase of Medicaid waiting list additions per 100,000 habitants, across all organs. Organ-specific estimates indicate potentially larger effects among in kidney transplantation (20.6% on average). The proportion of Medicaid enrollees added to the waiting list increased by 36.1%. and the proportion of Medicaid transplant candidates among all payers increased by 51.6%, relative to non-expansion states. Our findings suggest that increased coverage through Medicaid expansion resulted in better access to transplants´ waiting list, as well as to transplantation itself, albeit with smaller magnitude for the latter. The effect of coverage on access appears to operate through three different mechanisms – increased ability to afford care, disease detection, and crowding out of other insurance forms.