Utilization of Standard Criteria Donor and Expanded Criteria Donor Kidneys After Kidney Allocation System Implementation

BACKGROUND Implementation of the Kidney Allocation System (KAS) changed how kidneys are allocated and the information on which organ utilization decisions are based. We aimed to evaluate how KAS implementation changed kidney utilization and recipient outcomes. MATERIAL AND METHODS Using the United Network for Organ Sharing database, we identified recipients of kidney transplants from donors with kidney donor profile index (KDPI) of 61-90% in the 5-years pre- and 18-months post-KAS implementation and examined patient and graft survival and donor kidney discard rates based on standard criteria donor (SCD) or expanded criteria donor (ECD) status. RESULTS The proportion of ECD kidneys was unchanged pre- versus post-KAS. Post-KAS, SCD kidneys were less likely to be transplanted into young recipients while ECD kidneys were more likely to be transplanted. SCD kidneys in the post-KAS period conferred a 1.42 (95% CI: 1.18-1.73) times higher adjusted mortality and 2% lower 1-year survival (94.2% vs. 96.2%, P