Kidney Transplant Population Study Reveals Dramatic Outcome Changes

A Cleveland Clinic study on the national kidney transplant candidate population illustrates dramatic changes in outcomes, including declines in mortality rates.

Over the last 15 years, the study – “Dramatic Secular Changes in Prognosis for Kidney Transplant Candidates in the United States” – notes a significant decline in annual mortality rates on the kidney transplant waiting list, as well as notable declines in deceased and living donor transplantation. There also were significant increases in the rate of waitlist removal among transplant candidates.

The findings, according to lead researcher Jesse D. Schold, PhD, are important in considering prospective policy development, informed clinical and patient decision-making, and assessment of the impact of interventions and processes of care on these outcomes.

In the last two decades, the number of patients placed on the kidney transplant waiting list more than doubled. About 16 percent of patients with end-stage renal disease are placed on the waiting list within one year.

The study evaluated changes in mortality, transplantation and waitlist removal rates to assess patterns in the health and prognosis of the transplant candidate population. The intent was to provide data on prospective policy, decision-making, clinical care and research.

Mortality rates

An examination of 340,115 kidney transplant candidates between 2001 and 2015 on the national Scientific Registry of Transplant Recipients reveals a mixed bag of factors impacting prognosis of kidney transplantation candidates in the United States.

The main findings of the study found that mortality on the waiting list and transplant rates declined significantly, and waitlist removals increased significantly. The study also reveals the time to receive a deceased donor kidney transplant increased significantly nationwide due to the growing waiting list and relative stagnation of annual transplant rates.

“On the one hand, mortality is not as high; but you have to wait longer for a kidney, and the chances of being removed from the waitlist increase over time,” Dr. Schold says. “Decision-making may be affected – and viability may be affected – the longer they are on the waiting list.”

And while mortality rates decreased, those changes are highly variable among subgroups. African Americans, diabetics and patients with longer standing dialysis saw the most improvement.

The majority of transplant candidates are treated with maintenance dialysis. Mortality rates for patients on maintenance dialysis significantly declined nationally over the last two decades, suggesting the cumulative effect of dialysis exposure also declined over time.

Outcome

Dr. Schold attributes changes in prognosis to several factors, including increased demand for transplantation as more patients with end-stage renal disease are viable for the procedure, policy changes, changes in quality evaluations of transplant programs, and clinical advances.

“It’s a mixed bag of interpretations, in terms of how it affects prognosis,” Dr. Schold says.

Clinicians and transplant programs – as well as policy makers – still use 10-15-year-old data to determine waitlist eligibility and policy formulation. That data, he says, is outdated and potentially no longer relevant.

Significant changes in regulatory oversight of transplant centers occurred in the last decade, which may impact selection and management of the kidney transplant candidate population. Dr. Schold describes the oversight process for kidney transplant candidates as more rigorous than in any other aspect of health care. Programs that fail to meet certain quality benchmarks can lose public support or viability.

Dr. Schold says several studies show the unintended consequences of this oversight driving more risk-averse behavior. Programs are more reluctant to accept higher risk patients. The risks to the program are real, and there is some concern this is leading to more conservative practices.

“The findings of increased waitlist removals is concerning, and may be a product of this type of oversight,” he says. “Programs are becoming more stringent in listing and maintaining patients on the waiting list for concern of regulatory retribution.”

Dr. Schold says the study magnifies the need to update policies based on a more contemporary cohort.

A shortage of donors

The number of patients on the transplant waiting list is growing; something Dr. Schold attributes to population demographics. The most prominent risk factors for end-stage renal disease are age, diabetes, obesity and hypertension – all of which are increasing in the U.S. population. Patients also recognize that transplantation is the most desirable treatment for kidney disease.

But the rate of donors – both deceased and living – has not kept pace with the need. The reasons are unclear. The one exception in the past year or two is the opioid epidemic.

“Overdose patients are viable deceased donors,” he says. “That is one area of growth in transplant donors, but otherwise it is very flat; and unfortunately, we’ve not been able to increase the rates of donation in the country.”

Changing practice

Dr. Schold says while the study results may have an immediate impact on policies and research findings, translation for clinical care may take an intermediate step.

“It’s something that should be part of the conversation when clinicians are talking to their patients,” Dr. Schold says.