Health Equity

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Measuring Kidney Disease Progression May Be More Accurate Than a Single Measure of Organ Function, New Study Says 

The Focus on Progression Also Cut Disparities in Waiting List Times for Black and Hispanic Patients, but Not for Asian/Pacific Islander Patients

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Over 89,000 people in the U.S. are currently waiting for a kidney transplant, while more than 550,000 suffer from end-stage kidney disease and rely on dialysis. Kidney transplants offer a significantly better quality of life and longevity compared to dialysis, which is grueling and disruptive. Despite this, getting a transplant isn’t an easy endeavor. Long wait times mean 5,600 people in the U.S. die on the transplant waiting list every year.

Patients must undergo a thorough medical and psychosocial evaluation to ensure that a transplant is safe and effective for them. This process can be lengthy, and starting early can provide more opportunities to avoid dialysis and identify compatible living donors or accumulate waiting time on the deceased donor list before reaching a critical stage. In many regions, waiting times can exceed five years for a kidney.

One big challenge is to create a system that measures patients’ needs accurately and helps make organ allocation fairer for everyone—our team has some ideas on how to accomplish this.  

Racial and Ethnic Disparities

There are significant racial and ethnic disparities in kidney transplantation. Non-white patients often face reduced access to the waiting list, fewer living donors, and poorer outcomes after transplant. While many interventions have focused on educating patients and providers about the benefits of transplantation, systemic barriers in transplant eligibility also contribute to the problem.

In the U.S., to be listed for a deceased donor kidney transplant, a patient needs a documented blood test showing their kidney function (eGFR) is below 20%. Many transplant centers won’t start the evaluation process until this threshold is reached.

However, kidney diseases progress at different rates. Conditions like focal segmental glomerulosclerosis (FSGS), which are more common in Black and Hispanic individuals, lead to faster disease progression. This means that a Black patient with FSGS will have less time to complete the transplant evaluation, get on the waiting list, or find a living donor compared to a white patient with a slower-progressing condition.

A New Approach

Relying on a single measure of kidney function doesn’t adequately reflect a patient’s need for a transplant. A better approach would be to consider how quickly a person’s kidney disease is progressing. The kidney failure risk equation (KFRE) is a validated formula that predicts a patient’s two-year risk of needing dialysis or a transplant. It accounts for a patient’s age, sex, kidney function, and protein levels in their urine (which indicate more rapid progression).We studied patients in an electronic health record system to compare hypothetical waiting times if they started when their eGFR blood test was below 20% or when the KFRE predicted a 25% risk of kidney failure within two years. We then compared these hypothetical waiting times by race/ethnicity, looking at non-Hispanic white, Black, Hispanic, and Asian/Pacific Islander patients.

Findings and Implications

Our findings show that using the KFRE instead of a single eGFR measure would provide more waiting list time for patients before they needed dialysis or a transplant. The KFRE approach also reduced disparities in waiting times for Black and Hispanic patients, though not for Asian/Pacific Islander patients.

This study suggests that systematic and policy changes could help reduce racial and ethnic disparities in access to kidney transplantation. The Organ Procurement and Transplantation Network could consider adjusting eligibility policies to account for disease progression rates. Implementing the KFRE in clinical practice is a straightforward step that could make a significant difference.

The study, “Strategies to Guide Preemptive Waitlisting and Equity in Wait-Time Accrual by Race/Ethnicity,” was published in March 2024 in the Clinical Journal of the American Society of Nephrology. Authors include Elaine Ku, Timothy Copeland, Ling-Xin Chen, Matthew R. Weir, Charles E. McCulloch, Kirsten L. Johansen, Naeem Goussous, Jonathan D. Savant, Isabelle Lopez, and Sandra Amaral.

Author

Sandra Amaral

Sandra (Sandi) Amaral MD, MHS

Associate Professor, Pediatrics and Epidemiology, Perelman School of Medicine

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