The new Kidney Allocation System has not solved inequities that low-income and minority patients with kidney disease face when seeking the benefits of preemptive waitlisting for a transplant, Drexel University College of Medicine researchers reported in a study published in the Journal Clinical Transplantation.
Preemptive waitlisting allows patients with kidney disease to be listed for a kidney transplant before requiring dialysis.
“The goal of this study was to examine whether the new [Kidney Allocation System] KAS was associated with differences in pre-transplant dialysis durations for (deceased donor kidney transplant) recipients with and without preemptive waiting time,” wrote study lead author Meera Nair Harhay, MD, a nephrologist and associate professor of medicine at Drexel University College of Medicine, and colleagues. “We performed a retrospective pre-post cohort study to examine whether average pre-transplant dialysis durations differed among kidney transplant recipients before and after KAS implementation based on the recipient’s preemptive listing status and by race/ethnicity.”
Getting on a waitlist for a transplant – and avoiding dialysis – has for some time “been skewed toward patients with a higher socioeconomic status, access to better health insurance and primary care,” wrote Lauren Ingeno in a summary of the study for the newsletter Drexel Now. “Low-income and minority patients, by contrast, are disproportionately less likely to receive care for their disease early, and therefore spend much longer on dialysis.”
Harhay and colleagues performed a retrospective study of deceased donor kidney transplant (DDKT) recipients between Dec. 4, 2011 and Dec. 3, 2014, prior to the implementation of the KAS, and between Dec. 4, 2014 to Dec. 3, 2017, post-KAS. Among 65,385 DDKT recipients, “preemptively listed recipients (21%, n = 13,696) were more likely to be white (59% vs. 34%, P < 0.001) and have private insurance (64% vs. 30%, P < 0.001),” the authors wrote. “In the pre- and post-KAS periods, average adjusted pretransplant dialysis durations for preemptively listed recipients were [less than] 2 years 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).”
“You would expect that this new system would reshuffle the deck a bit and narrow this gap - so that someone who had been on dialysis for 2 or 3 years might get a kidney transplant before someone who has not started dialysis,” said Harhay in Drexel Now. “But we did not find that to be the case. The gap between those who were listed early and listed late is still quite wide.”
KAS also gives the highest-quality kidneys to those who have had the least years on dialysis, opening the door to further disparities based on the timing of waitlisting, Leone wrote.
“[This] study found that among kidney transplant recipients of all races and ethnicities, preemptive wait-listing continues to confer a large benefit with respect to minimizing pre-transplant dialysis duration compared to listing after dialysis under the new KAS,” Harhay and colleagues wrote. “Future studies should be directed at mitigating persistent drivers of disparate access to preemptive waitlisting.”
Disclosure: The study was supported in part by Health Resources and Services Administration contract 234-2005-37011C. The authors reported no relevant disclosures.