Nearly half of Americans with kidney failure referred for a kidney transplant never begin the evaluation process necessary to consider a donor organ, according to a new national survey. What’s even more surprising is that fewer than 1 in 5 people complete the evaluation and get placed on the transplant waiting list.
Researchers say that while much attention is paid to patients once they reach the waiting list, little is known about what happens up to that point and why so many people fail to make it.
Key barriers to kidney transplant waiting list
The study, led by researchers at New York University Langone Health, analyzed data from 720,348 patients referred for kidney transplants. The results revealed wide disparities in who gets to drive the process.
Patients who were unmarried, severely obese, or lived in rural areas were less likely to begin or complete transplant evaluation and ultimately reach the waiting list. Older adults, Spanish speakers, and low-income people faced even greater challenges. Patients treated at smaller transplant centers and programs in the southern United States were also less likely to move forward.
Overall, only 19% of referred patients completed the assessment process and were placed on the waiting list, and 48% did not initiate an assessment at all.
“Our findings suggest that a significant proportion of people who need a new kidney drop out of the process long before they even enter the operating room or even get on the waiting list,” said study lead author Conor Donnelly, MD. “Which transplant center you go to, where you live, and even whether you’re married appear to affect your chances of getting on the waiting list for a new kidney.”
Donnelly is a resident and doctoral student in the New York University Grossman School of Medicine Department of Surgery.
Why the evaluation process is difficult
The complexity of the transplant evaluation process may explain much of the variation seen in the study, Donnelly said.
After receiving a referral, patients must complete an extensive medical evaluation designed to assess their overall health. This often includes blood tests, chest imaging, cancer screening, and other tests. This process can require multiple appointments over several months while the patient continues to attend regular dialysis treatments.
Patients can only be added to the transplant waiting list if they meet these requirements and receive approval.
The researchers noted that smaller transplant centers may have fewer resources and fewer transplant opportunities available, which may allow them to be more selective when evaluating candidates. They also noted that unmarried patients and those with limited social support may face more difficulty arranging transportation and attending repeat medical appointments.
These factors may help explain why patients living in urban areas with easier access to transplant centers are generally more likely to continue with the transplant process.
Largest study of kidney transplant dropout rates
Published online on June 20th. American Society of Nephrology JournalAccording to the authors, this study is the largest and most detailed study to date to examine how patients are weaned off the kidney transplant pathway before being placed on the waiting list.
The study results will also be presented at the American Transplant Conference, an annual meeting co-sponsored by the American Society of Transplantation and the American Association of Transplant Surgeons.
To conduct their analysis, researchers used Epic Cosmos, a database containing more than 300 million electronic medical records from more than 1,850 hospitals, including more than one-third of U.S. transplant centers.
The research team looked at adults who were referred for kidney transplants between 2014 and 2025. Each patient was followed through four stages: referral, evaluation, waiting list, and transplantation.
Social and geographic factors influence results
Researchers used statistical modeling to assess how factors such as age, gender, medical history, and geographic location affect the likelihood of progressing from one stage to the next.
The team also studied social vulnerability, which reflects challenges related to living conditions and access to care. Examples include poverty, unstable housing, and limited transportation, all of which can make complex health systems more difficult to operate.
“These results demonstrate that finding ways to reduce barriers to both evaluation and waiting lists may help expand access to much-needed kidney transplants,” said study co-senior author Dr. Alan B. Massey, associate professor in the Department of Surgery and Population Health at New York University Grossman School of Medicine. “Providing better education and support to help patients navigate the complex and sometimes grueling process would be a good start.”
“Our findings highlight the need to better support patients from referral to waiting list, where many potentially eligible people end up not making it,” said study co-author Dr. Michal A. Mankowski.
Mankowski, assistant professor of surgery at New York University’s Grossman School of Medicine, said future studies will apply similar approaches to other types of organ transplants, where the path to the waiting list may be very different.
New York University Langone researchers involved in the project included Suhani Patel, MPH; Syed Ali Hussain, MD, MPH. Dr. Summer E. Gentry. Bonnie E. Ronze, MD. Sunjae Bae, MD; Babak J. Orandi, MD. Dr. Mara A. McAdams DeMarco. Dolly L. Segev, MD. Other collaborators include Rachel Patzer, PhD, MPH, of Indiana University in Indianapolis, and David Axelrod, MD, of University Hospitals of Cleveland.
Dr. Orandi serves on the advisory board of the pharmaceutical company Boehringer Ingelheim. NYU Langone Health governs the terms and conditions of this relationship in accordance with its policies and procedures.
NYU Langone Health funded this study.
