Reuters Health Information (2008-11-20): Relatively stable patients on liver transplant list not getting best organs: study
Relatively stable patients on liver transplant list not getting best organs: study
Last Updated: 2008-11-20 15:43:05 -0400 (Reuters Health)
NEW YORK (Reuters Health) - Since the Model for End-stage Liver Disease (MELD) organ allocation system was implemented in 2002, there has been a shift toward using poorer quality organs in patients least in need of a transplant (i.e., those with low MELD scores), research suggests.
"This has reduced post-transplant survival in recent years among patients with low MELD scores," the University of Michigan, Ann Arbor-based research team reports in the November issue of Gastroenterology.
"What's striking," first author Dr. Michael L. Volk noted in a university-issued press statement, "is that these patients typically have a low pre-transplant risk of mortality, and ultimately derive limited benefit, in terms of survival, from liver transplantation. In some cases, these patients may actually be harmed by a transplant, even with an organ of average quality."
Although priority for liver transplantation is determined by the MELD score -- a formula that uses creatinine, bilirubin and international normalized ratio levels to gauge mortality risk in people with liver disease -- the quality of organs used and the patients to whom they are given is subject to physician discretion, Dr. Volk and colleagues explain.
They set out to determine whether implementation of MELD has affected the quality of organs transplanted, the type of patients that receive the higher risk organs, and the impact of these changes on post-transplant survival.
To accomplish this, they analyzed data from the United Network for Organ Sharing (UNOS) for adults who underwent a deceased donor liver transplant between January 1, 1997 and August 1, 2007. Their analysis included estimates of the Donor Risk Index, which predicts the risk of graft failure associated with transplantation of a given organ.
Dr. Volk's team reports that the overall quality of transplanted livers has gotten worse since the implementation of the MELD-based priority system. In the 5 years since the system took effect, there has been a 4% rise in the Donor Risk Index after adjustment for temporal trends.
"This was accompanied by a shift from using the higher risk organs in the more urgent patients (in the pre-MELD era) to using the higher risk organs in the less urgent patients (in the post-MELD era)," according to the investigators.
As a result, post-transplant survival has worsened over time among patients with MELD scores less than 20.
"The most striking finding of this study was the complete reversal from the pre- to post-MELD eras in which organs were deemed acceptable for use in which patients," the investigators write. "This demonstrates how strongly changes in national policy can affect individual medical decisions."
"We do not favor revision of the MELD system, but rather restructuring of the reimbursement system for liver transplantation," they continue. "Under the current system, transplant centers lose money by transplanting patients with higher MELD scores because the cost becomes higher than the reimbursement."
They point out that there is no evidence that economic concerns have influenced clinical decisions. Still, they write, "the economic and clinical incentives here are clearly misaligned."