Donor Livers Don't Always Reach the Sickest First
Study: Simple change in transplant program would fix problem
TUESDAY, April 20, 2004 (HealthDayNews) -- Donor livers don't always get to the sickest people first, a new study has found.
Researchers from the University of Colorado Health Sciences Center discovered that rather than distributing donor livers regionally so the sickest patients received them first, the livers were often transplanted to less sick patients within a local organ procurement organization (OPO).
"Patients who are listed in an OPO with few patients are getting transplanted with less severe illness," said study author Dr. James Trotter, an associate professor of medicine at the University of Colorado Health Sciences Center in Denver.
Results of study appear in the April 21 issue of the Journal of the American Medical Association.
There are 59 OPOs across the United States, most of which are private, nonprofit organizations. Nine are hospital-based, according to the United Network for Organ Sharing (UNOS). Some OPOs cover populations of just over 1 million, while others serve populations as large as 18 million.
Each OPO maintains its own waiting list of transplant candidates; there is no national list. The largest OPO has more than 2,000 liver transplant candidates on its waiting list, while the smallest has fewer than 10. Currently, donor livers are matched within an OPO first, then to transplant candidates regionally, and then they are offered nationally, according to UNOS. More than 17,000 people in the United States are currently waiting for a liver transplant.
In February 2002, a new system was introduced for allocating donor livers to ensure that the sickest patients in an OPO would get transplanted first. Each transplant candidate is assigned a Model for Endstage Liver Disease (MELD) score. The higher the score, the more advanced the liver disease is.
For this study, Trotter and his colleagues looked at liver transplant data from the time MELD scores were implemented through March 2003 for 50 OPOs. The researchers considered an OPO small if fewer than 100 people were on its transplant list, and large if it had more than 100. Twenty-four percent of the OPOs studied were small, and 8.3 percent of the total transplants performed during the study period were done in small OPOs.
However, people in smaller OPOs had much higher transplant rates when the number of years on the waiting list was taken into account. The study found the transplantation rate was 2.5 times higher for people in a small OPO. Those in a small OPO were also more likely to receive a transplant when they weren't as sick.
"The current system works very well, but we've found a small problem that is important," said Trotter, who suggested that by redistributing the population in OPOs to make them more uniform, the problem could be fixed.
He said if each OPO served a population of about 9 million people, the system would be more equitable. But he noted that changing the layout of an OPO might mean some people would have to travel far distances to receive a transplant.
Dr. James Eason, director of the abdominal transplant program at Ochsner Clinic Foundation Hospital in New Orleans and a member of the UNOS committee that makes recommendations on donor organ allocations, said that anyone with a MELD score of 15 or higher benefits from transplantation. But if an OPO only has candidates with MELD scores below that number, he suggested the donor organ should be shared regionally, between OPOs, so the sickest people are given priority.
What's most important, he added, is to increase national attention on organ donation to raise the number of available donors.
"Instead of debating who gets what slice of the pie, we need to focus on making the pie bigger," Eason said.