Nearly half of patients referred for a kidney transplant drop out

Introduction: the invisible journey before the waiting list

A study that challenges common assumptions

We often imagine that a patient referred for a kidney transplant enters an almost automatic, linear path toward the waiting list. A large study led by researchers at NYU Langone Health and the NYU Grossman School of Medicine, published online on June 20, 2026 in the Journal of the American Society of Nephrology, shows that the reality is far more fragmented and far more discouraging.

The study analyzed 720,348 patients referred for a kidney transplant between 2014 and 2025, drawing on data from the Epic Cosmos platform, which pools more than 300 million electronic medical records from more than 1,850 hospitals, or over a third of American transplant centers.

The number that stands out the most

The central finding of this research is as simple as it is troubling: 48% of referred patients never even begin the evaluation process required to be considered for an organ donation. Only 19% of patients complete that evaluation and secure a spot on the transplant waiting list. An even lower figure deserves highlighting: only 10% of referred patients ultimately receive a transplant.

These numbers are not about a handful of isolated cases. They involve nearly three-quarters of a million people tracked over more than a decade, making this, according to the researchers themselves, the largest and most detailed study to date on the breaking points along the kidney transplant journey in the United States.

What "evaluation" actually means

A demanding, lengthy medical journey

The evaluation for a kidney transplant is not a simple administrative formality. It is a comprehensive medical workup designed to assess a patient's overall health, including blood tests, chest imaging, cancer screenings, and various other exams. This process generally requires multiple appointments spread over several months.

Throughout this evaluation period, patients must also keep showing up to their regular dialysis sessions, which in practice means juggling already physically demanding treatments with a series of additional exams. Only after completing all these requirements and receiving approval can a patient be added to the transplant waiting list.

The concrete timelines revealed by the study

According to the study's detailed data, the median time to begin evaluation, among patients who actually start it, is two months after the initial referral. The median time to then reach the waiting list, once evaluation begins, is four additional months. That means, at minimum, several months of sustained effort demanded of a patient already weakened by kidney failure.

These timelines, combined with the physical toll of dialysis, help explain why so many patients drop out along the way, without this necessarily reflecting a medical rejection of their candidacy.

The weight of marital status and social support

A factor you wouldn't expect in a medical file

Among the most surprising findings of the study is the influence of marital status on the likelihood of progressing through the process. Patients who have never been married show a reduced likelihood of beginning evaluation, with a relative risk of 0.94 compared to married patients, according to the study's precise published data.

This factor is partly explained by the process's implicit logistics: repeated appointments often require transportation, accompaniment, and logistical support that people with a limited social or family network find harder to sustain over several consecutive months.

Why this factor deserves special attention

Dr. Conor Donnelly, the study's lead author and a surgical resident-researcher at NYU Grossman School of Medicine, summed up this reality bluntly: "The transplant center you go to, where you live, and even whether you're married or not, all seem to influence your chances of moving forward on the waiting list for a new kidney."

This quote illustrates just how much factors that at first glance have nothing to do with medicine, like marital status, can have a measurable impact on real access to a life-saving treatment. It is not a question of medical merit, but of logistical capacity to sustain a demanding process.

Severe obesity, a documented obstacle

A factor that weighs heavily on the statistics

The study identifies severe obesity as one of the most decisive factors behind a reduced likelihood of beginning evaluation, with a relative risk of just 0.70 compared to patients without this condition. This is one of the sharpest gaps among all the factors measured in this research.

This gap is partly explained by legitimate surgical considerations: severe obesity can indeed complicate a transplant procedure and increase certain post-operative risks. But the size of this gap raises the question of whether the criteria applied are uniformly fair, or whether they sometimes exclude patients who, with proper support, could still benefit from a transplant.

What this means for health policy

Dr. Allan B. Massie, associate professor in the departments of surgery and population health at NYU and senior co-author of the study, said: "These results demonstrate that finding ways to reduce barriers to both evaluation and waitlisting could help expand much-needed access to kidney transplantation." He added: "Providing patients with better education and support to help them navigate this complex and sometimes grueling process would be a good place to start."

This statement points to a concrete path forward: rather than simply excluding patients with elevated risk factors, some centers could invest more heavily in personalized support that helps these patients overcome the logistical and medical obstacles identified by the study.

Geography, a factor too often underestimated

Rural areas particularly disadvantaged

Patients living in rural zip codes also show a reduced likelihood of beginning evaluation, with a relative risk of 0.98. While this gap is more modest than the one associated with severe obesity, it remains statistically significant across a sample of more than 720,000 patients, and it adds to other well-documented geographic barriers within the American health care system.

According to the study, patients living in urban areas were generally more likely to progress through the process, in part because transplant centers tend to be more physically accessible there, reducing the logistical burden of the repeated travel required by the evaluation.

The regional factor that surprises

Another striking finding concerns institutional geography: programs located in the southern United States were overall less likely to advance their patients through the process, compared to other regions of the country. Smaller transplant centers also showed a reduced relative transplant rate, with a relative risk of 0.92, likely due to more limited resources that make them more selective in evaluating candidates.

These regional and institutional gaps mean, in practice, that two patients with a similar medical profile could have very different odds of getting a transplant, simply based on where they live and which medical center they were referred to.

Social vulnerability, a revealing composite factor

Poverty, unstable housing, and limited transportation

The study highlights the role of social vulnerability as a whole, a factor that reflects challenges tied to living conditions and access to care. Among the examples cited by the researchers are poverty, unstable housing, and limited transportation options, three realities that, combined, can make simply showing up to repeated medical appointments over several months extremely difficult.

Lower-income patients, older individuals, and Spanish-speaking patients also face heightened challenges according to the study's data, painting a picture in which socioeconomic and language-based inequalities layer on top of the purely medical obstacles already documented.

Why so many patients are removed from the process

Among patients who never progress to evaluation at centers that documented the reasons for this non-progression, 18% simply did not meet the criteria or were not deemed candidates, 13% made the personal decision not to continue, 12% simply could not be reached by their medical team, 7% faced financial or insurance complications, and 4% died before being able to progress further.

This last figure, though the smallest in proportion, is a reminder of the human urgency behind these statistics: every additional month of delay in an already lengthy process represents a real risk for patients whose health can deteriorate quickly while waiting for a transplant.

What researchers propose as concrete solutions

Better support rather than simple filtering

Dr. Michal A. Mankowski, assistant professor in the department of surgery at NYU and also a senior co-author of the study, summed up the central issue: "Our results highlight the need to better support patients as they move from referral to waitlisting, where many potentially eligible people are ultimately never listed." This statement reframes the debate: the problem is not purely medical, it is also organizational and human.

The researchers suggest that targeted interventions, such as stronger logistical support for socially isolated patients, or education programs tailored to the language barriers identified, could reduce a significant share of this attrition without requiring a complete overhaul of the current system.

A presentation before the scientific community

These findings were presented at the American Transplant Congress, held in Boston from June 20 to 24, 2026, an annual conference jointly organized by the American Society of Transplantation and the American Society of Transplant Surgeons. This presentation before expert peers reinforces the scientific credibility of the conclusions, which underwent peer review before publication in a recognized journal in the field.

It is worth noting, in the interest of transparency, that some researchers involved in this study disclosed ties to the pharmaceutical industry, notably Dr. Babak J. Orandi, who served on an advisory board for the company Boehringer Ingelheim. These ties are publicly disclosed and managed according to NYU Langone Health's internal policies.

The financial barrier and insurance complications

A factor too often minimized in public debate

Among patients removed from the process at centers documenting their reasons, 7% of cases are directly attributable to financial or insurance complications. This figure, while a minority compared to medical criteria, reveals a well-known American reality: even a medically justified process can fail simply because a patient lacks the means or coverage needed to keep going.

The cumulative cost of the required exams, repeated travel, and sometimes lost income from missing work to attend evaluation appointments can represent a real obstacle for lower-income patients, particularly those who already combine several of the vulnerability factors identified by the study.

What this reveals about the limits of the current system

The American health care system, with its fragmented insurance structure, adds a layer of complexity that other countries with universal health care systems don't necessarily face to the same degree. A patient referred for a kidney transplant should, in theory, never drop out of the process purely for financial reasons, but this study's data suggests that is exactly what happens for a measurable share of the population studied.

This financial dimension of the problem extends well beyond the strictly medical realm, and it is a reminder that improving access to kidney transplantation likely cannot be limited to clinical reforms alone: it will also require addressing the structural economic barriers affecting the most vulnerable patients.

Conclusion: measured hope, not a promised miracle

What this study changes concretely, and what it does not yet change

This research offers no miracle treatment and no immediate solution to the chronic shortage of organs available for transplantation. Instead, it offers a precise map, unprecedented in scale, of the exact points where the current system loses patients who could potentially benefit from a kidney transplant. This is an important scientific contribution, but it has not yet been translated into concrete health policy at the national level.

Nothing in the available data guarantees that American transplant centers will quickly adopt the researchers' recommendations. Implementing stronger support programs requires human and financial resources that not every center, particularly smaller ones, necessarily has.

Why this statistical transparency remains valuable regardless

Simply quantifying precisely where and why patients drop out, with numbers as robust as those drawn from 720,348 medical records, already represents a significant step toward guiding future targeted interventions. This transparency allows transplant centers, insurers, and public health decision-makers to identify exactly where to focus improvement efforts.

For patients currently waiting for a kidney transplant, this study offers no immediate solution to their personal situation. But it represents a concrete step toward a potentially fairer system, provided its findings genuinely translate into changes in practice in the years ahead.

By Maxime Marquette, columnist

Columnist's transparency note

Who I am and my acknowledged biases

I am neither a doctor nor a nephrology researcher. I approach this story with a deliberate commitment to making complex scientific research accessible, without sensationalism and without promising a miracle solution to a structural problem that has been documented for decades in the American health care system.

I did not have access to the full text of the study published in the Journal of the American Society of Nephrology, which requires a subscription or payment. The data reported here comes from institutional press releases and specialized reporting that had access to the research's detailed findings.

What I don't know, and my method

I don't know whether the researchers' recommendations will actually be implemented by American transplant centers, or on what timeline. Nor do I know whether similar studies exist for other countries, which limits my ability to compare the American situation to other health care systems.

My method consists of faithfully reporting the figures and quotes directly attributable to the researchers and the specialized publications consulted, without extrapolating beyond what the sources allow me to state with certainty.

Sources

Primary sources

ScienceDaily — Nearly half of patients awaiting a kidney transplant never begin the process, July 2026

Clinical Briefing Report — Many patients referred for a kidney transplant do not even begin evaluation, July 2, 2026

ScienceDaily — Public health section

Secondary sources

ScienceDaily — Health and medicine section

PubMed Central — Related scientific article on barriers to kidney transplantation

ClinicalTrials.gov — Associated clinical study record