Kidney failure affects Black individuals at four times the rate of white individuals in the U.S.,[1] but fewer Black patients are put on kidney transplant waiting lists and even fewer receive transplants than their white counterparts across the country. For people with kidney failure and who are eligible, kidney transplantation is the ideal treatment. Many factors can play into an individual’s eligibility — including medical conditions and social determinants of health. However, it is likely that variability in clinical practices over the course of the transplant process (from patient referral to a transplant center, to wait listing to organ transplantation) also contribute to the racial inequity in transplantation.

To help identify at which stage of the transplant process racial disparities emerge, DaVita Clinical Research (DCR) conducted a study that tracked patients’ kidney transplantation journeys.

“The kidney community has known for some time now that racial disparities exist,” Dr. Francesca Tentori, Vice President of Outcomes Research and Patient Empowerment for DCR, says. “Our goal in this study was to identify steps in the transplant process where inequity exists so that we can start to address specific issues.”

DCR was able to leverage a dataset that spanned the U.S., providing a national-level picture for the first time. The cohort consisted of 60,229 patients — of which 61% of patients were identified as white and 39% were identified as Black. Patients with prior transplant or who had been evaluated for transplant prior to commencing dialysis were excluded. Also, this cohort was unique in that it contained detailed information about upstream parts of the transplant process, including when and if patients were referred or wait listed. Such data had been lacking in prior studies.

“We were looking for three primary outcomes, each reflecting successful completion of a distinct stage in the transplant process contingent on successful completion of prior stages,” says Dr. Steven Brunelli, Vice President and Medical Director of Health Analytics and Insights at DCR. “For the first time, we were able to look from dialysis start to referral for transplant evaluation, as separate from the time from referral to wait listing, as separate from the time from wait listing to receipt of transplant.

Results indicated that Black patients were actually more likely to be referred for transplant evaluation than white patients — as high as 22% more likely. However, referred Black patients had an 18% lower likelihood of being placed on the transplant waitlist and those who did get placed on the waitlist were 53% less likely to receive a transplant during the duration of the study.

Pushing for Equity in Transplantation

The primary finding of the study was that there are two key steps of the transplant process where inequity was found: wait listing and organ transplantation. Closer examination of the steps between referral and transplant receipt may identify opportunities to reduce racial disparities in kidney transplantation.

In this study, DCR also investigated the role of certain factors that, based on prior research, might contribute to observed racial disparities, including socioeconomic status, insurance type, and dialysis modality. Although each of these did play some role, their collective effects were limited relative to the magnitude of disparity seen in the current study. This strongly suggests that other structural barriers exist which mediate transplant racial disparities; these must be identified and ameliorated to promote equitable delivery of care.

This will become increasingly important as the U.S. kidney community, including the National Institutes of Health and the U.S. Department of Health and Human Services, is starting to place greater emphasis on transplantation as a form of treatment. New care models, including the End Stage Renal Disease (ESRD) Treatment Choices model (ETC Model), now outline specific goals surrounding kidney transplantation. DCR’s work highlights that emerging efforts must be viewed with an eye towards health equity so as not to exacerbate existing disparities.

Dr. Tentori explains:

“Knowing where we see disparity in the transplant journey enables the kidney community — including nephrology groups, transplant centers, and dialysis providers — to address the right issues to expand equity in transplant.”