A Restorative Justice Project in Kidney Allocation—The Wait Time Modification for Black and African American Candidates Affected by the Race-Based eGFR Equation

Introduction

As of January 2023, an Organ Procurement and Transplantation Network (OPTN) policy is in effect that requires transplant programs to assess their waiting lists and submit waiting time modifications for Black or African American candidates affected by race-inclusive eGFR calculations. Although system performance is monitored closely, the goal of eliminating disparity in access to kidney transplant in the setting of race remains elusive.

This wait time modification policy has been criticized as being unfair to people suffering under other inequities besides Black or African American race and as both unfairly too broad and too narrow. This brief perspective will highlight the process by which this project came about, the intended effect and the opportunities for other changes that this policy highlights, across the key areas of equity/fairness and access to waiting time.

Policy Changes to Decrease Inequity in Access to Transplant Associated with Race

Despite the OPTN's history of making policy changes to address racial inequities in access to transplant, these inequities have diminished but not disappeared.^1,2 A primary goal of the new Kidney Allocation System (KAS) in 2014 was to increase equity in allocation, particularly for ethnic and racial minorities. Under KAS, the waiting time clock began at wait list registration for those not yet on dialysis, but allowed for backdating of waiting time to the start of dialysis for those listed after chronic dialysis was started. This allowed a candidate's access to transplant to reflect documented medical need—when a patient first begins chronic dialysis—even if inadequate education about treatment options or delayed referral resulted in years of dialysis before listing. Post-KAS disparity in access to wait list priority persisted due to many contributing issues reviewed by Mohottige et al.,³ including the standard for calculating kidney function using race-based eGFR.

Race-Based Calculation of eGFR

Before the publication of the first Modification of Diet in Renal Disease formula,⁴ the interpretation of patient characteristics, including serum creatinine, to eGFR in an individual patient was largely the prerogative of the nephrologist because the actual measurement of GFR was and still is unwieldy and not widely available in clinical practice. The Modification of Diet in Renal Disease formula derived an eGFR from the measured GFR and clinical characteristics of roughly 1400 White patients and fewer than 200 Black patients in this study. When these Black patients on average had a higher creatinine for a given measured GFR, the authors concluded that it was based on the poorly substantiated assumption that Black people have more muscle mass. The race variable in the eGFR formula applied this assumption to all Black patients, differentiating Black or African American patients from every other race of patient, no matter their diet, muscle mass, or ethnic ancestry.

While at the time, the application of an eGFR formula to the laboratory report allowed an important, broad screening for CKD in the general population, it also supported the notion that on the basis of skin color, Black patients are somehow different than patients of any other race. As has been written about elsewhere, this perpetuated differential transplant referral and evaluation practices, contributing to racial inequities.⁵

The race variable eGFR resulting in the separation of Black kidney transplant candidates from every other race of candidate in having access to wait time accumulation is an example of race in algorithms that is not limited to the nephrology community. Race-inclusive algorithms guide decisions in ways that direct attention or resources away from racial and ethnic minorities.⁶ Although the intention of the use of a race variable in the eGFR was certainly not intentional expression of individual racism, it resulted in structural racism. This is demonstrated visually in Figure 1, which shows two young men with similar characteristics, including serum creatinine, but with different access to time on the transplant wait list based solely on race.

Figure 1.

Fictional example of structural racism using race-based eGFR calculation. Two young men, one White and one Black, both with a creatinine of 4.0. The White patient had access to transplant listing, whereas the Black patient did not, based solely on the effect his race has on his eGFR calculation. The images used are stock images and do not represent actual patients. MDRD, Modification of Diet in Renal Disease.

In July 2021, the OPTN Kidney Committee and Minority Affairs Committee sought community feedback on eliminating the use of race-based eGFR for the purposes of transplant listing, while the American Society of Nephrology-National Kidney Foundation task force on eGFR was finalizing their work not only to eliminate the use of the race variable in eGFR calculation but also to publish a race neutral and, importantly, more accurate formula in the CKD Epidemiology Collaboration Creatinine Equation (2021) publication.⁷ Prior policy left the method of GFR determination up to each transplant center, to reflect local policies, access to testing, and prevailing medical practice. In July 2022, the OPTN Board of Directors approved a policy change, widely supported during two rounds of public comment cycles, to ban the use of a race-based eGFR formula for purposes of transplant listing.

Wait Time Modification Policy Development

Feedback was received by the sponsoring committees to ask how we would address the situation of Black patients who were listed under the system of race-based eGFR. Work groups met to establish a way for Black patients affected by the race-based eGFR equation to get a modification or fix to their wait time.

The final policy was a good faith effort to balance the need for restitution of wait time with the standard of “hard evidence” used in the current kidney transplant allocation system. For the Black patient with an eGFR reflecting a value above 20, which if it was race neutral would be 20 or below, the opportunity for referral for transplant evaluation is lost. OPTN policy language has never dictated how GFR should be measured nor does not specify mg/dl or reference whether body surface area should be used in the calculation. Before 2022, debate on the amount of transplant wait list time actually lost because of the race variable was speculative. However, two publications, one small and one large, put that time between 1.3 and 1.9 years, respectively.^8,9 That quieted the skeptics who thought the race variable likely led to “inconsequential delays” in transplant candidacy. Our ultimate goal was to award wait time modification in an equitable and verifiable manner. The policy change followed the OPTN's well-outlined policy development process with patient input and was made after extensive discussion across committees, public comment, and regional meetings during late summer 2022. The final proposal was discussed further and approved at the OPTN Board of Directors in December 2022.

In brief, the policy has two main requirements, involving transparency and submission of evidence to justify wait time modification on a patient by patient basis. The transparency requirement involves notifying all patients on the waiting list of the intent to review the list for Black or African American candidates that could qualify for wait time adjustment. The submission of a laboratory value with the eGFR above 20 with race but 20 or below without is meant to justify waiting time modification. This puts the burden on the transplant center to, patient by patient, look for data showing that they could have, but were not, sent for transplant earlier than their registration date. The ultimate improvement in fairness and accuracy in transplant listing should be reassuring to patients on the list of any race, even if they were not affected by the race variable and do not qualify for a wait time adjustment.

This pathway for wait time modification allows for wait time to even predialysis waiting time, which is not a path for wait time available to other patients on the list. Providing this pathway is meant to address the wait time deficit specifically related to the race-based variable, which only potentially affects some Black of African American candidates who had laboratory work performed during progression through CKD stage 4–5. However, it opens the broader question of backlisting all patients to a time when their eGFR was 20, regardless of referral for transplant. This is a separate and important question that has strong advocates on both sides. The recent National Academy of Science Engineering and Medicine report¹⁰ specifically recommends against any predialysis wait time accumulation, proposing that this pathway be abolished for all patients, to focus kidney allocation to those patients on dialysis. It is beyond the scope of this review to weigh in on this complex topic, but it is worthy of a robust and data-driven debate going forward. However, the current wait time modification policy is intended to address patients affected by the race-based variable. Only Black patients are eligible for this because only Black patients (not any other race) had the higher race-based eGFR value applied to their laboratory creatinine measurement, thus affecting their access to transplant listing. The community needs to engage in a robust debate regarding the merits of predialysis wait time accumulation regardless of referral date for all patients with CKD.

In summary, the wait time modification policy, implemented in 2023, seeks to redress the race-based delay in transplant access that applied to only people registered as Black or African American. It only applies to Black patients who had a race-based eGFR before the registration date that would have justified listing had the race variable not been used. One cannot argue this is the best pathway, the fairest, or the timeliest to redress this disparity in access to transplant for Black patients. However, short of turning our backs on the patients who are waiting for transplant who were affected by the widespread use of the Black race variable, the committees involved decided that it is the best next step in not just addressing or lowering but actually eliminating the disparity in access to kidney transplant that has affected Black patients since the inception of the organ allocation system.

Disclosures

M. Pavlakis reports Consultancy: Merck and Vertex; Research Funding: site PI for APOLLO study, site PI for CareDx OKRA study, and site PI on trial for Trugraf Genomics study TRULO; Advisory or Leadership Role: Moderna Study SAFETY REVIEW COMMITTEE; and Other Interests or Relationships: OPTN/UNOS Chair, Kidney Transplantation Committee. This work is my own and the content of this publication does not reflect the views or policies of the Organ Procurement and Transplantation Network.

Funding

None

Author Contributions

Conceptualization: Martha Pavlakis.

Supervision: Martha Pavlakis.

Writing – original draft: Martha Pavlakis.

Writing – review & editing: Martha Pavlakis.