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The Algorithm Change That Closed a Race-Based Medical Disparity

A few rule changes have helped close the gap between how likely black and white Americans are to get a kidney transplant in a time of need.
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(Photo: Tareq Salahuddin/Flickr)

(Photo: Tareq Salahuddin/Flickr)

Among the many ways racial bias shows up in the American medical system: who receives kidney transplants. (This is true of other organs as well, but we'll only talk about kidneys for now.) Until recently, whites in need of transplants were more likely to receive them than blacks or Hispanics. So in December 2014, officials changed the algorithm that determines who's prioritized for donated kidneys. Now, just about a year later, a new study shows the change worked.

The evidence comes from a paper published last month in the Journal of the American Society of Nephrology. The study's authors, a team of transplant researchers and epidemiologists, examined data on who receives kidneys from cadaver donors. In the year before the algorithm change, blacks and Hispanics who needed kidney transplants were less likely to receive an organ from a deceased donor. Afterwards, transplant rates rose for both blacks and Hispanics, the study found.

There were, however, some problems following the algorithm alteration. For one, more people saw their new implants fail. That's because, after the system change, donated kidneys spent more time on ice before being transplanted into a person. In addition, slightly more donated kidneys were tossed out before they could be transplanted into a patient—a wasteful fate that happens to nearly one out of five kidneys donated by those who have died.

What changes made the difference? One was the prioritization of patients who had spent more time on dialysis. Historically, it's taken longer for Hispanic and black people to get onto kidney waitlists, but to spend a longer time on dialysis. Previously, the algorithm counted how long a person had been on the waitlist—and not dialysis—as a factor in deciding who next gets a transplant. That's changed, and the amount of time someone spends on dialysis now also counts. (Previous rule changes went a long way toward closing the gap between white and black kidney transplant recipients.)

Doctors and patients have been waiting for these changes for a long time, so it's good to see them work, even if they do come with some drawbacks. In the future, transplant policymakers can tweak the rules further, the new study's authors suggest: To help individuals get the transplants they need, medical organizations may want to further encourage people to donate their organs upon death, and to better monitor harvested kidneys to make sure they stay viable.


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