Maximizing kidney transplant equity means minimizing geography

For decades, geography heavily influenced who received kidney and other organ transplants in the United States and who didn’t.

An assessment released late last year of a new national policy, which takes a more logical approach to allocating kidneys, indicates that the days when an individual’s place of residence dictates whether they live are on the wane. This is good news for those needing a kidney, who make up the vast majority of patients on the transplant waitlist.

The new policy, which was specifically designed to increase transplant equity, became effective in March 2021. The assessment report, issued in October by the United Network for Organ Sharing (UNOS), shows that the policy is working as intended and making access to deceased donor organs more fair. What’s more, the total number of kidney transplants rose 22%, from 4,926 to 6,025, over the course of four months after the policy was instituted.

When the U.S. organ donation and transplantation system was founded in the mid-1980s, the federal government divided the country into more than 100 “donor service areas,” though the number has since been whittled down. Some are geographically large, like the one that covers the entire states of Minnesota, North Dakota, and South Dakota; others are small, like the one that covers the Washington D.C. metropolitan area. Each service area is overseen by an organ procurement organization, which has the responsibility for recovering organs from donors who live within its geographic area.

The common-sense decision was made in the 1980s to use these donor service areas to determine who would be offered the organs that were recovered in them. The unintended consequence of this decision was that too many people on organ transplant waiting lists were not offered organs they qualified for simply because they lived outside the arbitrary boundaries of a donor service area.

The new kidney policy made a simple but crucial change. It replaced donor service area borders with 250-mile-wide circles around donor hospitals, the places where organs are recovered. It makes sense to redraw the geographic borders within which patients will be offered kidneys around the hospitals where the donor organ originates.

The findings from the October assessment report are good news for the 90,000 people in the U.S. waiting for kidneys — approximately 85% of the total number of people on the transplant waitlist. Since the policy change:

• Kidney transplants are up 22% overall, with increases across all age groups and blood types
• Two-thirds of kidney transplant programs had the same number or more kidney transplants
• Pediatric kidney transplants increased
• The number of kidney transplants increased among Black and Hispanic patients, and those who had been on dialysis longer
• The percentage of kidneys deemed unusable by transplant teams remained stable

The vast majority of transplants are now taking place within 250 nautical miles of the donor hospital.

UNOS, which operates under federal oversight to set policy for the nation’s transplant system and offers matched organs to patients and their medical teams, will continue to monitor the new kidney policy through 2023 to assess its effectiveness and flag any unintended consequences.

Committees convened by UNOS constantly evaluate and improve equity across the system. As a member of UNOS’s kidney committee since 2014, and its chair from 2019 to 2021, I know firsthand that these committees have been working collaboratively and methodically to build one policy on top of the next in the drive toward optimal equity.

In 2013, for example, Black individuals made up 34% of patients on the kidney transplant waiting lists yet accounted for 32% of deceased donor kidney transplants. White candidates, on the other hand, represented 36% of the waiting list but accounted for 42% of recipients.

Faced with this disparity, UNOS convened committees of organ donor and transplant stakeholders to write policies intended to increase kidney transplants among Black and Hispanic individuals, who tend to spend more time on dialysis than white candidates. That’s largely due their historically not being referred for transplant evaluation as expeditiously due to issues of inequity across the U.S. health care system.

The resulting policy change in 2014 gave higher priority to those who had spent longer on dialysis. The percentage of Black candidates receiving kidney transplants initially rose sharply after this change, from 32% to 40%, reflecting a surge in the number of Black people who received kidney transplants. By 2018, it had tapered to 34%, which aligned with Black patients’ percentage on the national waitlist at that time, suggesting improved equity.

While the policy was deemed largely successful, it exposed the system’s issues with equity relative to geography. For example, though incorporating time spent on dialysis helped improve transplant rates for Black recipients, it revealed that designated service areas with high numbers of Black residents still had a disproportionate number of people waiting for kidneys, thus creating longer wait times for them.

This realization set the stage for the next big kidney policy push: the effort to replace designated service areas with 250-mile circles around donor hospitals as the geographic borders within which patients are offered kidneys.

While the circles-based approach is a great step in making transplant geography more equitable, it is just a step. The system’s next advance is a framework called continuous distribution. In this framework, it will be possible to develop a composite score for every individual needing a transplant that incorporates multiple factors, such as medical urgency, waiting time, and individual biology. For example, a patient with a harder-to-match blood type would receive more points compared to a patient with an easier-to-match blood type when a donor organ that is compatible with both candidates becomes available.

UNOS will monitor the effectiveness of continuous distribution through ongoing data analysis. If the data suggest too much emphasis is being placed on one factor and not enough on another, or if medical advances offer opportunities to further refine matching, adjustments to the composite score can be made easily and quickly.

As a transplant clinician, I am one of many stakeholders in the U.S. system — potential recipients and their families, donors and their families, teams that recover organs and those that perform transplants — who are energized by the capacity of continuous distribution to further drive equity.

The many participants in the national organ donation and transplant system will continue advocating for, and creating, more equitable policies that ensure the best possible organ match for everyone on the transplant waitlist — regardless of who they are or where they live.

Vincent Casingal is a transplant surgeon, chief of abdominal transplantation, and surgical director of the kidney transplant program at Atrium Health in Charlotte, North Carolina.