By Hendra Lukman 
A groundbreaking national study has illuminated a critical bottleneck in the kidney transplant process, revealing that nearly half of Americans suffering from kidney failure who are referred for a transplant evaluation never even begin the necessary steps to be considered for a life-saving donor organ. The findings are even more stark for those seeking a place on the transplant waitlist: fewer than one in five referred patients successfully complete the rigorous evaluation and secure a spot. This represents a significant and largely unaddressed challenge in the organ transplantation system, leaving many potentially eligible individuals without access to a treatment that could dramatically improve or extend their lives.
Researchers behind the study, conducted by NYU Langone Health, have highlighted that while significant attention is often focused on patients once they are on the transplant waitlist, a vast and concerning knowledge gap exists regarding the critical pre-waitlist stages. The study sought to understand what transpires between a referral and the ultimate goal of being listed for a transplant, and crucially, why so many individuals falter along this demanding path.
Major Disparities Emerge in Transplant Access
The comprehensive analysis, which delved into data from an immense cohort of 720,348 patients referred for kidney transplantation, uncovered significant and concerning disparities in who is able to navigate the complex evaluation process and subsequently reach the transplant waitlist. These inequities are not randomly distributed but are demonstrably linked to a confluence of socioeconomic, demographic, and geographic factors.
Patients who were unmarried, struggled with severe obesity, or resided in rural communities were found to be less likely to initiate or successfully complete the transplant evaluation. This suggests that support systems, accessibility to healthcare facilities, and potentially societal norms play a crucial role in patient progression. The challenges become even more pronounced for older adults, individuals who primarily speak Spanish, and those with lower incomes. These groups face compounded difficulties in accessing information, navigating bureaucratic processes, and meeting the multifaceted demands of the evaluation.
Furthermore, the study identified that the choice of transplant center and its location also significantly influence a patient’s journey. Those receiving care at smaller transplant centers or programs situated in the Southern United States were observed to have a lower likelihood of advancing through the evaluation process and onto the waitlist. This could be attributed to a variety of factors, including resource limitations at smaller centers, differences in transplant program policies, or regional disparities in healthcare access and patient education.
Collectively, these findings paint a sobering picture: only a mere 19% of all referred patients managed to complete the comprehensive evaluation and secure a position on the national transplant waitlist. In stark contrast, a staggering 48% of referred patients never even commenced the initial evaluation phase.
"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 lead author Conor Donnelly, MD, 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."
The Labyrinthine Nature of the Transplant Evaluation Process
Dr. Donnelly and his colleagues posit that the inherent complexity and demanding nature of the transplant evaluation process itself is a primary driver behind the observed variations in patient progression. The journey from referral to waitlisting is not a simple one; it is a meticulously designed, multi-stage process intended to ensure that candidates are medically suitable for transplantation and will benefit from the procedure.
Upon receiving a referral from their nephrologist, patients are typically required to undergo an extensive medical assessment. This evaluation is designed to gauge their overall health status, identify any potential contraindications to surgery and lifelong immunosuppression, and determine their ability to adhere to post-transplant care regimens. The process often encompasses a battery of tests, including comprehensive blood work to assess organ function and screen for infections, advanced imaging such as chest X-rays and CT scans, and various cancer screenings. It may also involve consultations with a multidisciplinary team of specialists, including surgeons, nephrologists, social workers, dietitians, and psychologists.
Crucially, this evaluation process can span several months, during which patients must continue their regular dialysis treatments, which are themselves time-consuming and physically demanding. The need for multiple appointments, often spread out over weeks or months, can create significant logistical challenges, particularly for individuals who lack reliable transportation, have demanding work schedules, or face other social or economic constraints. Only after successfully meeting all the stipulated requirements and receiving unanimous approval from the transplant team can a patient be formally added to the national kidney transplant waitlist.
The researchers also speculated on the role of transplant center resources and selectivity. Smaller transplant centers, potentially operating with fewer staff, financial resources, and a lower volume of transplant surgeries, might adopt a more stringent selection criterion for candidates. This could lead them to be more cautious in advancing patients to the waitlist, especially if there are concerns about a patient’s ability to adhere to complex post-transplant protocols.
Moreover, the study noted that social factors, such as marital status and the presence of a strong social support network, appear to be critical determinants of success. Unmarried individuals or those with limited family or friend support may encounter greater difficulties in arranging transportation to appointments, managing the emotional and practical demands of the evaluation, and ensuring consistent follow-up care. Conversely, patients residing in urban areas, where transplant centers are often more concentrated and accessible, generally demonstrated a higher likelihood of progressing through the evaluation process, likely due to greater proximity and potentially more robust support services available in these locales.
A Landmark Study Sheds Light on Transplant Dropout Rates
The findings of this study, published online on June 20 in the Journal of the American Society of Nephrology, represent the most extensive and in-depth examination to date of patient attrition rates within the kidney transplant pathway prior to waitlisting. The research is also being presented at the prestigious American Transplant Congress, a key annual gathering for the organ transplantation community, jointly organized by the American Society of Transplantation and the American Society of Transplant Surgeons.
To conduct this monumental analysis, the research team leveraged Epic Cosmos, a vast database encompassing over 300 million electronic health records from more than 1,850 hospitals across the United States. This dataset includes records from over one-third of all organ transplant centers in the nation, providing an unparalleled scope for understanding patient journeys.
The study meticulously tracked adults who were referred for kidney transplantation between the years 2014 and 2025. Each patient’s progress was monitored through four distinct stages: referral, evaluation, waitlist inclusion, and ultimately, transplant. This longitudinal approach allowed researchers to precisely identify where and why patients were exiting the transplantation pipeline.
Social Determinants and Geographic Location Profoundly Influence Outcomes
Employing sophisticated statistical modeling techniques, the researchers rigorously evaluated the influence of various factors on a patient’s likelihood of advancing from one stage to the next. Beyond traditional medical history and demographic markers such as age and sex, the study placed significant emphasis on social vulnerability. This concept, which encapsulates challenges related to living conditions, access to essential resources, and overall socioeconomic status, was examined through indicators such as poverty levels, housing stability, and the availability of reliable transportation. These factors, the study underscores, can profoundly impede an individual’s ability to navigate complex healthcare systems and adhere to demanding treatment regimens.
"These results demonstrate that finding ways to reduce barriers to both evaluation and waitlisting could help expand much-needed access to kidney transplantation," commented 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."
Echoing this sentiment, co-senior author Michal A. Mankowski, PhD, an assistant professor in the Department of Surgery at NYU Grossman School of Medicine, emphasized the broader implications: "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 indicated that future research will build upon this foundation by applying a similar analytical framework to other types of organ transplantation, acknowledging that the pathways to waitlisting can differ significantly depending on the organ in question.
The research team involved in this critical study included a robust group of scientists from NYU Langone Health: 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. Additional collaborators contributing to this significant work were Rachel Patzer, PhD, MPH, from Indiana University in Indianapolis, and David Axelrod, MD, from University Hospitals in Cleveland.
It is noteworthy that Dr. Orandi has served on an advisory board for the pharmaceutical company Boehringer Ingelheim. NYU Langone Health has confirmed that the terms and conditions of this relationship are being managed in accordance with its established policies and procedures. The study itself was funded by NYU Langone Health.
Broader Implications for Healthcare Policy and Patient Advocacy
The implications of this study extend far beyond the realm of academic research. The stark disparities in access to kidney transplantation underscore the urgent need for a re-evaluation of current healthcare policies and practices. The findings suggest that simply referring patients for evaluation is insufficient; robust systemic support is required to ensure that all eligible individuals can successfully navigate the process.
The identification of specific barriers – such as social vulnerability, geographic location, and socioeconomic status – points towards targeted interventions that could improve equity in organ transplantation. This might include expanding access to patient navigators who can guide individuals through the complex evaluation process, offering financial assistance for transportation and lodging for appointments, and developing culturally sensitive educational materials for diverse patient populations.
Furthermore, the role of transplant center resources and geographic distribution warrants further investigation. Policies aimed at supporting smaller transplant centers or improving access to transplantation in underserved regions could help mitigate some of the observed disparities.
Patient advocacy groups and healthcare providers are likely to use these findings to push for policy changes and increased funding for programs that support pre-transplant evaluation and waitlisting. The study provides concrete evidence to support the need for a more equitable and accessible organ transplantation system, ultimately aiming to save more lives and improve the quality of life for individuals suffering from kidney failure. The continued pursuit of such research is vital for understanding and dismantling the systemic barriers that prevent many from receiving the life-altering gift of a kidney transplant.
