By Hendra Lukman 
A groundbreaking nationwide study has unveiled a deeply concerning trend within the U.S. kidney transplant system: a staggering number of individuals suffering from kidney failure, who are deemed candidates for a life-saving transplant, never even initiate the rigorous evaluation process. The research, published in the Journal of the American Society of Nephrology, reveals that nearly half of all patients referred for a kidney transplant fail to commence the necessary steps to be considered for a donor organ. The situation is even more dire when looking at completion rates, with fewer than one in five patients successfully navigating the evaluation and securing a coveted spot on the national transplant waitlist. This sobering statistic highlights a critical bottleneck in the organ transplantation pathway, where significant numbers of potentially eligible patients are falling through the cracks long before they can be considered for a new kidney.
The study, a comprehensive analysis of over 720,000 patients referred for kidney transplantation, was spearheaded by researchers at NYU Langone Health. It underscores a significant gap in our understanding of the pre-waitlist journey, an area that has historically received far less attention than the challenges faced by patients once they are on the waitlist. While much research and public discourse often focus on the intricacies of waitlist management, organ allocation, and post-transplant care, this new study pivots the spotlight to the crucial, and often overlooked, initial stages of the transplant process.
Identifying the Hurdles: Major Barriers to Kidney Transplant Waitlisting
The NYU Langone Health study, utilizing data from the expansive Epic Cosmos database, which encompasses over 300 million electronic health records from more than 1,850 hospitals, including a substantial portion of U.S. transplant centers, meticulously tracked patients from their referral stage through evaluation, waitlisting, and ultimately, transplantation. This extensive dataset allowed researchers to identify significant demographic and geographic disparities in who successfully progresses through the transplant pathway.
The findings paint a stark picture of inequity, revealing that certain patient populations face considerably greater obstacles in reaching the transplant waitlist. Individuals who were unmarried, struggled with severe obesity, or resided in rural communities demonstrated a lower likelihood of both initiating and completing a transplant evaluation. The disparities were even more pronounced for older adults, Spanish speakers, and individuals with lower incomes, all of whom encountered amplified challenges. Furthermore, the study indicated that patients receiving care at smaller transplant centers or those located in programs within the Southern United States were also less likely to advance in the process.
Cumulatively, the research found that a mere 19% of all referred patients managed to complete the comprehensive evaluation process and earn a place on the transplant waitlist. In stark contrast, a disheartening 48% of referred patients never even took the first step by starting the evaluation.
"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," stated Dr. Conor Donnelly, the study’s lead author and a resident and PhD student in the Department of Surgery at NYU Grossman School of Medicine. "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."
This assertion highlights the multifaceted nature of the barriers, suggesting that systemic factors, geographical access, and even social determinants of health play a significant role in determining a patient’s ability to access a potentially life-saving organ transplant.
The Labyrinthine Evaluation Process: Understanding the Challenges
Dr. Donnelly and his colleagues posit that the inherent complexity and demanding nature of the kidney transplant evaluation process itself likely accounts for a significant portion of the observed variations. For patients referred for a transplant, the journey involves an exhaustive medical assessment designed to ascertain their overall health and suitability for such a major procedure. This typically includes a battery of tests, such as extensive blood work, chest imaging, cancer screenings, and various other specialized examinations. The entire evaluation can span several months and necessitate multiple appointments, all while the patient is concurrently undergoing regular dialysis treatments, a process that is itself time-consuming and physically taxing.
It is only after successfully meeting all these stringent requirements and receiving formal approval from the transplant team that a patient can be officially added to the national kidney transplant waitlist.
The researchers also pointed to potential resource limitations at smaller transplant centers. These centers may possess fewer resources and a more limited capacity for performing transplants, potentially leading them to adopt a more selective approach when evaluating potential candidates. Additionally, the study noted that patients who are unmarried or lack robust social support networks may face considerable difficulties in coordinating transportation to and from frequent appointments, as well as managing the logistical demands of a prolonged evaluation period.
This factor could help explain why patients residing in urban areas, where transplant centers are generally more concentrated and accessible, tended to have a higher likelihood of progressing through the evaluation process. The proximity and availability of transplant services appear to be a critical determinant in a patient’s ability to navigate the system.
A Landmark Study: Unpacking Kidney Transplant Dropout Rates
Published online on June 20th in the Journal of the American Society of Nephrology, this research represents the most extensive and detailed examination to date of patient attrition rates at various stages of the kidney transplant pathway prior to reaching the waitlist. The findings are also being presented at the prestigious American Transplant Congress, the annual gathering jointly organized by the American Society of Transplantation and the American Society of Transplant Surgeons, underscoring the significance of this new data for the transplant community.
The methodological rigor of the study is noteworthy. Researchers leveraged Epic Cosmos, a vast database that aggregates electronic health records from a substantial number of U.S. hospitals, providing an unparalleled view into patient care pathways. By examining adult patients referred for kidney transplantation between 2014 and 2025, the team was able to meticulously follow each patient’s progression through four distinct phases: referral, evaluation, waitlisting, and ultimately, transplantation. This longitudinal approach enabled a precise quantification of dropout rates at each critical juncture.
The Interplay of Social and Geographic Factors on Transplant Outcomes
Employing sophisticated statistical modeling, the research team delved into how a multitude of factors, including patient age, sex, medical history, and geographic location, influenced the probability of advancing from one stage of the transplant process to the next. Beyond these clinical variables, the study also critically examined "social vulnerability," a concept that encapsulates the myriad challenges individuals face due to their living conditions and access to healthcare. This includes factors such as poverty, housing instability, and limited transportation options, all of which can significantly impede a person’s ability to navigate the complexities of a specialized medical system like organ transplantation.
"These results demonstrate that finding ways to reduce barriers to both evaluation and waitlisting could help expand much-needed access to kidney transplantation," commented Dr. Allan B. Massie, a co-senior author of the study and 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."
The sentiment is echoed by Dr. Michal A. Mankowski, another co-senior author and an assistant professor in the Department of Surgery at NYU Grossman School of Medicine. "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," Dr. Mankowski stated. He further indicated that future research endeavors will employ a similar analytical framework to investigate other types of organ transplantation, acknowledging that the pathways to waitlisting can exhibit considerable differences across various organ systems.
The study’s implications extend beyond the immediate concern of kidney transplantation. The identification of social and geographic determinants of access underscores a broader societal challenge in ensuring equitable healthcare for all. The findings serve as a clarion call for a systemic re-evaluation of how patients are supported throughout the complex journey of organ transplantation, from the initial referral to the ultimate goal of receiving a new organ.
Broader Implications and Future Directions
The research’s meticulous data collection and analysis provide a robust foundation for understanding and addressing the significant attrition observed in the kidney transplant pathway. The identification of specific patient groups and geographic areas experiencing greater barriers suggests targeted interventions could be developed. For instance, enhancing patient education and support services, particularly for those with limited social support or living in underserved regions, could prove invaluable. Mobile clinics, culturally sensitive outreach programs, and dedicated patient navigators could help bridge the gaps in access and understanding.
Furthermore, the findings may prompt transplant centers to re-examine their evaluation protocols. Streamlining certain aspects of the process, where medically appropriate, or offering more flexible appointment scheduling could reduce the burden on patients. A more coordinated approach between referring nephrologists, primary care physicians, and transplant centers could also ensure a smoother transition for patients.
The study’s authors and their colleagues are actively involved in disseminating these critical findings. The presentation at the American Transplant Congress ensures that the findings are directly communicated to the leading experts in the field, fostering discussion and potential policy changes. The collaborative nature of the research, involving multiple institutions and a wide array of NYU Langone Health researchers including 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, along with external collaborators Rachel Patzer, PhD, MPH, of Indiana University and David Axelrod, MD, of University Hospitals, highlights a concerted effort to tackle this complex issue. It is important to note the disclosure regarding Dr. Orandi’s advisory board role with Boehringer Ingelheim, managed by NYU Langone Health according to its policies, indicating transparency in potential conflicts of interest.
Ultimately, this landmark study serves as a critical impetus for action. By shedding light on the silent crisis of pre-waitlist attrition, it provides the evidence needed to advocate for systemic changes that can expand access to kidney transplantation, offering hope and a chance at a longer, healthier life for the thousands of Americans who desperately need it. The path forward requires a multi-pronged approach, involving healthcare providers, policymakers, and patient advocacy groups, all working collaboratively to dismantle the barriers and ensure that every eligible patient has a fair opportunity to be considered for a life-saving kidney transplant.
