Nearly half of kidney transplant patients never even get started

Researchers say much attention has been given to patients after they reach the waitlist, but far less is known about what happens before that point and why so many people never make it there.

Major Barriers to Kidney Transplant Waitlisting

The study, led by researchers at NYU Langone Health, analyzed data from 720,348 patients referred for kidney transplantation. The findings revealed significant disparities in who advances through the process.

Patients who were unmarried, had severe obesity, or lived in rural communities were less likely to begin or complete a transplant evaluation and ultimately reach the waitlist. Older adults, Spanish speakers, and people with lower incomes faced even greater challenges. Patients receiving care at smaller transplant centers or programs located in the Southern United States were also less likely to move forward.

Overall, just 19% of referred patients completed the evaluation process and were placed on the waitlist, while 48% never started the evaluation at all.

"Our findings suggest that a substantial proportion of people who need a new kidney fall out of the process long before they reach the waitlist, let alone make it to the operating room," said study lead author Conor Donnelly, MD. "Which transplant center you go to, where you live, and even whether you are married all appear to influence your chances of moving forward to the waitlist for a new kidney."

Donnelly is a resident and PhD student in the Department of Surgery at NYU Grossman School of Medicine.

Why the Evaluation Process Can Be Difficult

According to Donnelly, the complexity of the transplant evaluation process may explain much of the variation seen in the study.

After receiving a referral, patients must complete an extensive medical assessment designed to evaluate their overall health. This often includes blood tests, chest imaging, cancer screenings, and other examinations. The process may require multiple appointments over several months while patients continue attending regular dialysis treatments.

Only after completing these requirements and receiving approval can a patient be added to the transplant waitlist.

Researchers noted that smaller transplant centers may have fewer resources and available transplant opportunities, which could lead them to be more selective when evaluating candidates. They also pointed out that patients who are unmarried or have limited social support may face greater difficulties arranging transportation and attending repeated appointments.

These factors may help explain why patients living in urban areas, where transplant centers are often more accessible, were generally more likely to continue through the process.

Largest Study of Kidney Transplant Dropout Rates

Published online June 20 in the Journal of the American Society of Nephrology, the research is the largest and most detailed study to date examining where patients leave the kidney transplant pathway before reaching the waitlist, according to the authors.

The findings are also being presented at the American Transplant Congress, the annual meeting jointly organized by the American Society of Transplantation and the American Society of Transplant Surgeons.

To conduct the analysis, researchers used Epic Cosmos, a database containing more than 300 million electronic health records from over 1,850 hospitals, including more than one-third of US transplant centers.

The team examined adults referred for kidney transplantation between 2014 and 2025. Each patient was tracked through four stages: referral, evaluation, waitlist, and transplant.

Social and Geographic Factors Influence Outcomes

Using statistical modeling, the researchers evaluated how factors such as age, sex, medical history, and geographic location affected the likelihood of advancing 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 options, all of which can make navigating complex medical systems more difficult.

"These results demonstrate that finding ways to reduce barriers to both evaluation and waitlisting could help expand much-needed access to kidney transplantation," said study co-senior author Allan B. Massie, PhD, an associate professor in the Departments of Surgery and Population Health at NYU Grossman School of Medicine. "Providing patients with better education and support to help them navigate the complex and sometimes grueling process would be a good start."

"Our findings highlight the need to better support patients in progressing from referral to the waitlist, where many possibly eligible individuals are not ultimately listed," said study co-senior author Michal A. Mankowski, PhD.

Mankowski, an assistant professor in the Department of Surgery at NYU Grossman School of Medicine, said future research will apply a similar approach to other types of organ transplantation, where the path to the waitlist can differ significantly.

Additional NYU Langone researchers involved in the project included Suhani Patel, MPH; Syed Ali Husain, MD, MPH; Sommer E. Gentry, PhD; Bonnie E. Lonze, MD, PhD; Sunjae Bae, MD, PhD; Babak J. Orandi, MD, PhD; Mara A. McAdams DeMarco, PhD; and Dorry L. Segev, MD, PhD. Other collaborators included Rachel Patzer, PhD, MPH, of Indiana University in Indianapolis and David Axelrod, MD, of University Hospitals in Cleveland.

Dr. Orandi has served on an advisory board for the pharmaceutical company Boehringer Ingelheim. NYU Langone Health is managing the terms and conditions of this relationship in accordance with its policies and procedures.

NYU Langone Health funded the study.