Unintended Consequences in Use of Increased Risk Donor Kidneys in the New Kidney Allocation Era

The new kidney allocation system (KAS) intends to allocate the top 20% of kidneys to younger recipients with longer life expectancy. We hypothesized that the new KAS would lead to greater allocation of Public Health Service (PHS) increased-risk donor organs to younger recipients.Analyses of the Organ Procurement and Transplantation Network data of patients who underwent primary deceased kidney transplantation were performed in pre- and post-KAS periods.The allocation of PHS increased-risk kidney allografts in various age groups changed significantly after implementation of the new KAS, with an increased proportion of younger individuals receiving increased-risk kidneys (7% vs 10% in age group 20-29 y and 13% vs 18% in age group 30-39 y before and after KAS, respectively; P .0001). This trend was reversed in recipients 50-59 years old, with 31% in the pre-KAS period compared with 26% after KAS (P .0001).The new KAS resulted in a substantial increase in allocation of PHS increased-risk kidneys to candidates in younger age groups. Because increased-risk kidneys are generally underutilized, future efforts to optimize the utilization of these organs should target younger recipients and their providers.