Association of the kidney allocation system with dialysis exposure before deceased donor kidney transplantation by preemptive wait-listing status

Background It is unknown whether the new kidney transplant allocation system (KAS) has attenuated the advantages of preemptive wait-listing as a strategy to minimize pretransplant dialysis exposure. MethodsResultsWe performed a retrospective study of adult US deceased donor kidney transplant (DDKT) recipients between December 4, 2011-December 3, 2014 (pre-KAS) and December 4, 2014-December 3, 2017 (post-KAS). We estimated pretransplant dialysis durations by preemptive listing status in the pre- and post-KAS periods using multivariable gamma regression models. Among 65385 DDKT recipients, preemptively listed recipients (21%, n=13696) were more likely to be white (59% vs 34%, P<0.001) and have private insurance (64% vs 30%, P<0.001). In the pre- and post-KAS periods, average adjusted pretransplant dialysis durations for preemptively listed recipients were <2years in all racial groups. Compared to recipients who were listed after starting dialysis, preemptively listed recipients experienced 3.85 (95% Confidence Interval [CI] 3.71-3.99) and 4.53 (95% CI 4.32-4.74) fewer average years of pretransplant dialysis in the pre- and post-KAS periods, respectively (P<0.001 for all comparisons). ConclusionsPreemptively wait-listed DDKT recipients continue to experience substantially fewer years of pretransplant dialysis than recipients listed after dialysis onset. Efforts are needed to improve both socioeconomic and racial disparities in preemptive wait-listing.