Almost half of the people in the United States who have kidney failure and are sent a referral for a transplant never start the required evaluation. Even fewer—under one in five—complete all the steps and get placed on the official waiting list.
Researchers say most studies look at what happens after a patient reaches the list. Very little is known about why so many never get that far.
Key Reasons People Drop Out
A team from NYU Langone Health examined data from 720,348 patients who were referred for kidney transplants. The numbers showed clear gaps.
- People who are not married, who have severe obesity, or who live in rural areas are less likely to start or finish the evaluation.
- Older adults, Spanish speakers, and those with low income face even bigger hurdles.
- Patients treated at smaller transplant centers or at hospitals in the Southern U.S. also move forward less often.
Overall, only 19% of referred patients completed the whole evaluation and were added to the waiting list. Meanwhile, 48% never began the evaluation at all.
Why the Evaluation Is Hard
The evaluation includes many medical checks: blood work, chest scans, cancer screens, and other tests. These appointments can stretch over several months while the patient continues regular dialysis.
Only after all tests are finished and doctors give approval can a patient be listed.
Smaller centers often have fewer resources and may be more selective. Patients without a spouse or strong social support may struggle with transportation and keeping many appointments.
Those living in cities, where transplant centers are more common, tend to have a better chance of staying in the process.
Largest Study on Drop‑Out Rates
The findings were published online on June 20 in the Journal of the American Society of Nephrology and were shared at the American Transplant Congress.
Researchers used the Epic Cosmos database, which holds over 300 million electronic health records from more than 1,850 hospitals—including more than a third of U.S. transplant centers.
They followed adults referred for kidney transplants from 2014 to 2025 through four steps: referral, evaluation, waitlist, and transplant.
Social and Geographic Factors Matter
Statistical models showed that age, sex, medical history, and where a person lives all influence the chance of moving to the next step.
Researchers also looked at “social vulnerability,” which means problems like poverty, unstable housing, and limited transportation. These issues make it harder to navigate a complicated medical system.
Future work will use the same methods to study other organ transplants, where the path to the waitlist can be very different.