International registry review shows advantage in outcomes for US transplant recipients drops after first year
While kidney transplant recipients in the United States initially have better outcomes compared to patients in other countries, registry data show that advantage disappears after the first year, according to a study published in the American Journal of Transplantation.
The authors of the paper, led by Robert M. Merion, MD, of the Arbor Research Collaborative for Health, said some of those diminishing outcomes — the authors of the study estimate U.S. patients had a 25% greater risk of graft failure after the first year — may be due to how those transplant patients are managed.
“ ... There are other differences in health care systems and potentially identifiable differences in post-transplantation care practice patterns that would be candidates to study as factors leading to disparate kidney transplant outcomes around the world,” the authors wrote. “Focused studies of transplant center practices (eg, the extent to which uniform patient care guidelines are used; the timing and extent of return of care responsibility from the transplant center to local physicians; differences in immunosuppression practices) are needed to better understand the differences in outcome we observed and to suggest interventions in post-transplantation care to test as best practices.”
In the study, the authors did a retrospective review of 379,257 first-time transplant recipients listed in the Scientific Registry of Transplant Recipients for the United States, the National Health Service Blood and Transplant for the United Kingdom, and the Australia and New Zealand Dialysis and Transplant Registry. The transplants took place from 1988 to 2014.
Data showed that, within the first year after transplant, the United States and Australia had significantly better outcomes compared to the United Kingdom as measured by graft failure, which was defined as patient death, the need for a re-transplant, transplant nephrectomy or initiation of or return to dialysis. Patients in Australia had the best outcomes in the first year.
However, “we found that the risk of long-term graft failure among those whose grafts were functioning at 1 year was approximately 25% lower in Australia, New Zealand and the United Kingdom than in the United States,” the authors wrote. Case mix differences and residual confounding from unmeasured factors did not seem a likely explanation, they wrote in the paper.
In a statement released by Arbor Research about the study, Merion said, “The dramatic difference in long-term outcome in the United States compared to three other countries with well-developed kidney transplant systems should concern patients. Roughly 3 years of time with a functioning kidney – off dialysis – are being forfeited by U.S. patients, for reasons that are unknown at present. This is unacceptable.”
In an interview with NN&I, John S. Gill, MD, MS, professor of medicine at the division of nephrology at the University of British Columbia in Vancouver, Canada and deputy editor of the American Journal of Transplantation, said the lack of long-term, coordinated management of transplant patients in the United States, concerns about access to immunosuppressive drug therapy to protect the transplanted kidney – the U.S. Medicare program, for example, only offers 3 years of prescription coverage post-transplant – and the focus on first-year outcomes among transplant centers to meet performance standards could all play a part in the long-term results shown in the study.
“The positive things shown in this study [are] that [outcomes] are getting better over time in all countries,” he said. However, he agreed that “transplant centers are highly attuned to 1-year outcomes” because of pressure to meet performance standards. As a result of that approach, “the entire system in the U.S. in the long term is not geared toward transplant programs providing direct care for their patients,” he said. That care is divided up among a number of health care professionals, while in other countries, “patients are often treated directly by the transplant center over a long period of time,” he noted.
The authors of the paper published in the American Journal of Transplantation did look at whether a patient’s health care insurance in the United States played a role in the diminishing outcomes, but the results showed graft failures occurred both among patients with Medicare and commercial health plan coverage.
“In each of the countries other than the United States in the study, health insurance coverage and medication availability are universal,” the authors wrote. “Our sub-analysis showed that recipients in the United States with private health care insurance and government-funded health care insurance (Medicare/Medicaid) each had significantly higher risks of long-term graft failure than recipients in Australia, New Zealand and the United Kingdom.”
Among the transplanted patients from the three registries, living donor organs were used for 36% of transplants in the United States; 33% in Australia; 40% in New Zealand; and 25% in the United Kingdom. The authors also noted that the proportion of zero HLA-mismatched transplants was higher in the United States (8.8%) and the United Kingdom (9.4%) than in Australia (5.2%) and New Zealand (5.4%). – by Mark E. Neumann
Disclosure: The authors reported no relevant financial disclosures