The formula for allocating livers for transplants, known as the Model for End-stage Liver Disease—or MELD—score, has been in place since 2002, and according to a report in the journal Liver Transplantation, “many constituent groups” are satisfied with the current system but would like to see incremental changes aimed at reducing wait-list deaths and minimizing travel distances for organs.
Changes in liver transplant system proposed
The MELD formula is designed so that the sickest person receives the first available liver, and it measures the patient's risk of dying from liver disease without a transplant. A local, regional and then national tier system is used that calls for a local patient most at risk, classified as “1A,” getting the liver first, followed by a regional 1A patient. If there are no regional 1A patients, then a local 1B patient would get the liver before a wider or even national net is cast.
But, according to the report, “These geographic boundaries are to some degree arbitrary, are not uniform across the country, and are not based on any metric related to liver distribution.” Computer modeling has shown that by expanding the initial distribution unit from local to regional would increase the median distance an organ for transplant would travel to about 127 miles from 65, but would result in 61 fewer deaths, the report noted.
The authors point out, however, that most of the waiting list deaths occur among patients with low MELD scores because, numerically, they make up the largest group.
In an accompanying editorial, Dr. Richard Freeman Jr. of the Dartmouth Medical School, Lebanon, N.H., wrote that “It seems self-evident that small changes in distribution or allocation policies are not likely to lead to large changes in results,” and he also questioned the accuracy of the models used to make predictions included in the report.
Freeman concluded that disparities in allocation would only be significantly altered when sharing areas are increased, but he added that “the liver transplant community and perhaps many state regulators are not ready to make this leap.”
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