Geographic disparity in kidney transplantation under KAS

• Published in: American journal of transplantation Vol. 18; no. 6; pp. 1415 - 1423
• Main Authors: Zhou, Sheng, Massie, Allan B., Luo, Xun, Ruck, Jessica M., Chow, Eric K. H., Bowring, Mary G., Bae, Sunjae, Segev, Dorry L., Gentry, Sommer E.
• Format: Journal Article
• Language: English
• Published: United States Elsevier Limited 01.06.2018
• Subjects: Adult; Dialysis; Female; Geography; Health Care Rationing; Humans; Kidney Transplantation; kidney transplantation/nephrology; Kidney transplants; Male; Middle Aged; organ allocation; organ procurement and allocation; Organ Procurement and Transplantation Network (OPTN); organ procurement organization; Pediatrics; Poisson Distribution; Renal Dialysis; Scientific Registry for Transplant Recipients (SRTR); Tissue and Organ Procurement; translational research/science; Transplants & implants; United Network for Organ Sharing (UNOS); Organ Procurement and Transplantation Network (OPTN); translational research/science; organ procurement organization; kidney transplantation/nephrology; organ procurement and allocation; organ allocation; Scientific Registry for Transplant Recipients (SRTR); United Network for Organ Sharing (UNOS)
• ISSN: 1600-6135; 1600-6143
• DOI: 10.1111/ajt.14622

The Kidney Allocation System fundamentally altered kidney allocation, causing a substantial increase in regional and national sharing that we hypothesized might impact geographic disparities. We measured geographic disparity in deceased donor kidney transplant (DDKT) rate under KAS (6/1/2015‐12/1/2016), and compared that with pre‐KAS (6/1/2013‐12/3/2014). We modeled DSA‐level DDKT rates with multilevel Poisson regression, adjusting for allocation factors under KAS. Using the model we calculated a novel, improved metric of geographic disparity: the median incidence rate ratio (MIRR) of transplant rate, a measure of DSA‐level variation that accounts for patient casemix and is robust to outlier values. Under KAS, MIRR was 1.751.811.86 for adults, meaning that similar candidates across different DSAs have a median 1.81‐fold difference in DDKT rate. The impact of geography was greater than the impact of factors emphasized by KAS: having an EPTS score ≤20% was associated with a 1.40‐fold increase (IRR = 1.351.401.45, P < .01) and a three‐year dialysis vintage was associated with a 1.57‐fold increase (IRR = 1.561.571.59, P < .001) in transplant rate. For pediatric candidates, MIRR was even more pronounced, at 1.661.922.27. There was no change in geographic disparities with KAS (P = .3). Despite extensive changes to kidney allocation under KAS, geography remains a primary determinant of access to DDKT. Geography remains a primary determinant of access to deceased donor kidney transplant despite extensive changes to kidney allocation under the Kidney Allocation System.