PROJECT SUMMARY For the nearly 95,000 people currently waiting for a kidney transplant, their geographic residence has a major impact on whether they will get a transplant. Organ allocation is based on geographic boundaries of donor service areas (DSA) that are artificial. There are 58 DSA in the US, and they vary tremendously in size and population, which explains some of the variation in access to transplantation. The geographic boundaries of DSAs were never designed to optimize organ allocation, and do not account for population, prevalence of kidney disease, or organ donation rates. These geographic boundaries might also contribute to another important problem – unnecessary discard of donated kidneys. Nearly 20% of all kidneys donated in the US are discarded. Improving access to transplant and reducing kidney discard are national priorities under the “Advancing American Kidney Health Initiative.” A new kidney allocation policy that does not use any fixed geographic boundaries is scheduled for implementation in December 2020. However, the new organ allocation policy may have unintended effects on organ outcomes and worsen disparities in access to transplant. This grant will examine three eras of kidney allocation that reveal how the use of geographic boundaries has affected transplant benefits and equity for patients with end-stage kidney disease: 1) Historical Allocation Era: Transplants performed before 12/4/2014, when kidneys procured within a DSA were allocated primarily to recipients within the same DSA; 2) Kidney Allocation System Era (split into two sub eras): Kidneys considered “lower quality” were shared over a wider region until 9/5/2019, and this policy was subsequently reversed due to high kidney discard rates; 3) Concentric Circle Era: This system is scheduled for implementation on 12/15/2020 and eliminates DSA boundaries, and uses a 250-nautical mile radius around donor hospital to allocate kidneys. The overall objective of this scientific proposal is to determine the effects of wider geographic sharing of deceased donor kidneys on the specific outcomes of kidney discard, disparities in access to transplant, and recipient outcomes. My central hypothesis is that systems with wider sharing of deceased donor kidneys might reduce geographic inequities for patients living in areas with high wait-times, but it will worsen organ discard and fail to improve kidney allograft survival. These novel insights into the relationship between geography and kidney allocation could ultimately drive major public health gains for patients with kidney disease by showing how kidneys can be allocated to improve fairness and increase the number of transplants. The applicant has an appointment on the junior faculty at the University of Pennsylvania. With the support of a highly experienced mentorship team and the ample resources available at the University of Pennsylvania, his goal is to foster a career of enduring research as an R01 funded independent...