A recent policy change in how patients are assessed for a kidney transplant has helped Black patients get on the list of those waiting for donor organs — and has helped more patients get lifesaving treatment, according to a new study from Boston-area researchers.

The paper, published in March in the journal JAMA Internal Medicine, looked at how retroactively adjusting wait times affected patients waiting for an organ and found that on average, Black people earned nearly two years of time on the waitlist — raising their priority level for a kidney. The study also found that because of the policy change, there were roughly five more kidney transplants performed per 1,000 Black patients.

“I think this paper is an incredible example of how rigorous science, advocacy and attention to these kinds of historic harms … can really lead to the meaningful and necessary changes that we’re all seeking,” said Dr. Dinushika Mohottige, a nephrologist and health equity professor at Mount Sinai Health System in New York. Mohottige wasn’t involved in the study but co-authored an invited commentary in response.

Those historic harms refer to how, for over two decades, who got a kidney transplant from organ donors was governed by a clinical algorithm that assessed risks in chronic kidney disease and the need for a transplant. That algorithm was built around measuring how well the kidneys were able to filter out creatinine, a by-product of everyday metabolism, from blood.

The worse the algorithm said a person’s kidney function was, the more likely they were to be eligible for a kidney transplant.

The algorithm was designed to consider a host of factors, including a patient’s race. But bias in the way that algorithm was built meant Black patients needed to have a higher creatinine level — meaning their kidney function had to be much worse than patients of other demographics — to get on the waitlist for a transplant. A longer time on the waitlist often meant a higher priority. Black patients who didn’t get put on the waitlist until after other patients with similar severity of disease therefore tended to be considered a lower priority to receive an organ.

“If you’re waiting for a transplant, no matter what your race is, you’re best served by a system that is as fair and unbiased as possible,” said Dr. Martha Pavlakis, a nephrologist at Beth Israel Deaconess Medical Center and a senior author on the paper.

It was with that aim that in 2021 the National Kidney Foundation and American Society of Nephrology recommended removing race as a variable in the algorithm — a push which Pavlakis helped champion during her time chairing the Kidney Committee of the Organ Procurement and Transplantation Network (OPTN), the federal system that coordinates the organ transplant system. In early 2023 the OPTN called on transplant centers to review patient records and retroactively recognize the time that they would have been on the waitlist were it not for the race-based formula.

The new study specifically considered the impact of that policy change on wait-listed kidney transplant candidates in the United States from January 2022 to June 2025.

“The question this paper asked is, ‘What happened to the transplant rate after this policy was implemented?’” Pavlakis said. “The very simple answer was that the disparity in access to kidney transplants that affected Black patients was improved.”

Specifically, the team found that retroactively adjusting the wait times recognized — and included as a priority factor for receiving a kidney — a median 1.7 years, in the wait-list for Black patients. Overall, the more than 22,100 patients whose wait time was modified gained a combined 51,061 years of time they would otherwise have not had. The study also found that there were 5.3 more transplants, on average, per 1,000 Black patients on the list.

For many patients, that shift could be significant. Pavlakis said that in her experience, the average time a patient spends on the wait-list for a donor kidney is between three and five years. Previous research found that the use of race-based factors in the kidney algorithm delayed the transplant eligibility listing of Black patients by a median of 1.9 years.

“If you have to ‘five years and you’re being held back from 1.9 of those five years because you’re Black, you can see that’s pretty impactful,” Pavlakis said.

Notably, patients of other ethnicities did not see any gains from modifying the algorithm, underscoring how Black patients were at a particular disadvantage before the policy change.

“We weren’t bumping people up on the list because they were Black,” Pavlakis said. “We were implementing a change that actually made the list a more accurate reflection of people’s need for kidney transplant.”

Following the changes, Mohottige said she saw patients move to the top of the list and more quickly receive a donor kidney.

Importantly, perhaps, the policy shift — and the new evidence of its efficacy — are a potential bellwether for other changes such as reconsidering the use of race in algorithms, Mohottige said.

“There is nothing truly biologic about race,” Mohottige said. “If we’re going to develop clinical algorithms to predict across broad populations what’s going on with the population, race should not be something that we are equating with a true biologic or genetic risk. We should be seeking a far more precise way of understanding what that is.”

More broadly, however, reevaluating medical practices may be a way to right past wrongs. “This is one of many clinical algorithms that embedded race. Some have changed; some are in the process of changing,” Mohottige said. “As a country, how can we look at who is harmed and who was helped, and how can we try to repair some of those harms?”