Measuring and monitoring equity in access to deceased donor kidney transplantation

The Organ Procurement and Transplantation Network monitors progress toward strategic goals such as increasing the number of transplants and improving waitlisted patient, living donor, and transplant recipient outcomes. However, a methodology for assessing system performance in providing equity in access to transplants was lacking. We present a novel approach for quantifying the degree of disparity in access to deceased donor kidney transplants among waitlisted patients and determine which factors are most associated with disparities. A Poisson rate regression model was built for each of 29 quarterly, period-prevalent cohorts (January 1, 2010-March 31, 2017; 5years pre-kidney allocation system [KAS], 2years post-KAS) of active kidney waiting list registrations. Inequity was quantified as the outlier-robust standard deviation (SDw) of predicted transplant rates (log scale) among registrations, after discounting for intentional, policy-induced disparities (eg, pediatric priority) by holding such factors constant. The overall SDw declined by 40% after KAS implementation, suggesting substantially increased equity. Risk-adjusted, factor-specific disparities were measured with the SDw after holding all other factors constant. Disparities associated with calculated panel-reactive antibodies decreased sharply. Donor service area was the factor most associated with access disparities post-KAS. This methodology will help the transplant community evaluate tradeoffs between equity and utility-centric goals when considering new policies and help monitor equity in access as policies change. The authors present a novel methodology for measuring equity in access to kidney transplants among waitlisted candidates, revealing substantial recent improvements but also significant residual disparities driven primarily by four factors: donor service area of listing, calculated panel reactive antibodies, blood type, and diagnosis leading to renal failure. See the editorial from Formica on page 1837.