Revised equation moves thousands of Black Americans higher on kidney transplant waitlist

When Mario Hicks was put on the waitlist for a kidney transplant in 2019, his doctors told him that it probably would be 10 years before his turn would come. In the meantime, his life revolved around being hooked up to an at-home dialysis machine for nine hours a day.

Four years later, after a race-based factor was removed from a formula used to determine kidney function, Hicks, 43, and thousands of other Black Americans got moved up on the long transplant waitlist. Last fall, the truck driver for the city of Chicago underwent a successful transplant at Loyola University Medical Center, a Trinity Health hospital in suburban Chicago.

Since his transplant, Hicks no longer must spend more than a third of his day tethered to a device. "I actually have time to enjoy life with my wife, with the kids," says Hicks, the father of two adult children.

In June, he and his wife vacationed in Mexico to celebrate their anniversary. He happily left behind the two pieces of luggage he had needed in recent years to carry his dialysis supplies. "It was much easier," Hicks says.

New calculation
The formula adjustment that changed the calculus for Hicks and other Black Americans waiting for a kidney transplant was approved in June 2022 by the United Network for Organ Sharing, which oversees the nation's donation and transplant system. The network said the change was "intended to address disparities in waiting times faced by Black patients on the kidney transplant waitlist."

The calculation that changed involved the glomerular filtration rate, a measure of how quickly a person's kidneys remove a waste product called serum creatinine from the blood. The rate is used to determine the point of kidney failure and when a patient is eligible to be put on the transplant waitlist. Since 2009, race had been one of the factors in the calculation, along with age, sex and the amount of serum creatinine in the blood.

The change that removed race from the calculation took effect Jan. 5, 2023. In addition, the United Network for Organ Sharing required transplant centers to review their waitlists and credit time to any patients who had been affected by the old formula.

A year later, the network said the revised formula had resulted in recalculations of the timing of kidney failure for 14,701 Black transplant candidates, with a median of 1.7 years of wait time credited. Wait times are among the variables that factor into prioritization for transplants. Of the transplant candidates whose wait times were revised, the network said 2,709 received a deceased donor transplant and 158 received a living donor transplant.

Wait times can mean the difference between life and death for kidney patients. The Department of Health and Human Services says there were more than 90,000 patients on the waitlist for a transplant last year and just over 28,000 operations. The United Network for Organ Sharing says 13 people die every day waiting for a kidney.

Significant impact
Sanjeev Akkina is a transplant nephrologist and medical director for the kidney transplant program at Loyola Medicine, of which Loyola University Medical Center is part. He estimates that the change that expedited Hicks' transplant affected as many as half of Loyola Medicine's Black patients on the waitlist. He says that translates into 40-50 people.

"It was a pretty significant number," Akkina says.

The change also had a significant impact for dozens of patients with kidney failure at SSM Health Saint Louis University Hospital. Of 118 Black patients on the transplant waitlist whose records were reviewed by the hospital, 68 gained additional credit for wait time and 12 got transplants earlier than they would have if not for the change.

Dr. Krista Lentine, an SSM Health nephrologist specializing in the treatment of adult patients with kidney disease, says the revised transplant formula is an indication of changing times in health care.

"Across medical disciplines, there is increasing recognition that categorizing race as a biologic rather than social construct has contributed to health care disparities," Lentine says. "This problem is particularly apparent in the burden of kidney disease, which affects Black Americans three to four times as often as white persons."

She was among 10 researchers who published a study in October 2021 on the use of the glomerular filtration rate in the calculations for kidney function. The study found strong support among staff at kidney transplant centers for revising the equation to improve transplant access. The findings were shared with the taskforce that was evaluating the revised equation.

An unintended consequence
Lentine says race was part of the earlier equation because it had been identified in kidney research data as associated with glomerular filtration rate. That research had shown, based on self-reported race, a difference between Black and white patients in measures of glomerular filtration rate levels. Research has never established what the root cause of the difference was.

The fact that the formula meant Black patients waited longer than other patients for kidney transplants, Lentine says, "was an unintended consequence of prior allocation policy, not a factor in how the original equations were developed or planned for use."

The study Lentine and other researchers published notes: "Critics have argued that use of race in clinical tools, although ostensibly in service to precision, is a poor proxy for individual genetic differences, exacerbates inequities, and may propagate structural racism."

In terms of addressing disparities in kidney care for Black Americans, Akkina says revising the formula used to determine kidney failure "was one of the easier fixes we could do." Among the more difficult and more impactful fixes the nation could undertake, he and Lentine say, would be addressing social factors that affect health. Those factors include access to screenings for diabetes and other conditions that can lead to kidney failure and access to transportation to medical appointments.

A fair chance
Hicks says his doctors never diagnosed the cause of his kidney failure. By the time it was detected in 2015, his kidney function was only 50%. It wasn't until he went on dialysis in 2019 that his doctors told him he also would be put on the transplant list.

He didn't know that race had been a factor in how he was prioritized for a transplant until last year, when he learned from the transplant center in Iowa where he was also on a transplant registry that he likely qualified for a wait time adjustment. Once that adjustment was made, his turn for a transplant came up quickly at Loyola.

Hicks says he can't say enough about the quality of care he received there and how grateful he is to have a new kidney. He would like to see more done to identify and address disparities like the one that might have delayed his transplant.

"I just hope that they change the system all around for fairness, for whatever race or color, (so) that everyone gets a fair chance at getting a kidney donated," he says.

Related story: Catholic hospitals part of national effort to increase organ donation among people of color