OPTN statement regarding liver transplant waiting times and allocation
Published on: Wednesday, June 24, 2009
Recent news regarding liver transplantation has raised public questions regarding how donated livers are allocated and potential variation in transplant waiting times. The national Organ Procurement and Transplantation Network (OPTN), operated by United Network for Organ Sharing (UNOS) under federal contract, cannot discuss details of individual transplant candidates subject to federal laws and regulations regarding patient confidentiality. The OPTN can address general questions about policy and process.
Whenever a person known to the public receives a transplant, it is tempting to compare that person's waiting time to national averages. Any comparison of one person's experience to that of thousands of others can be misleading.
Liver waiting time is greatly influenced by a formula that assigns priority for organ offers based on the candidate's risk of dying within three months without a transplant. For candidates 12 or older, this formula is called a MELD score. (Younger candidates are prioritized by a companion system known as PELD).
MELD uses objective calculations of common laboratory tests of liver and kidney function. MELD scores can range from 6 (least urgent) to 40 (most urgent); candidates with a score of 15 or higher are at considerable risk of dying in the short term without a transplant.
OPTN policy prioritizes liver candidates local to the organ donor with a MELD or PELD score of 15 or higher, then those candidates within the region of the donor who have scores of 15 and higher, before any less urgent candidates may be considered.
Of candidates listed in the United States with an initial MELD or PELD score between 19 and 24, half receive a liver transplant within approximately 15 weeks of being listed. Of those listed with an initial MELD or PELD score of 25 or higher, half receive a transplant within 20 days of listing. Candidates with lower MELD/PELD priority may often wait months to years for a transplant opportunity.
Other factors may further affect waiting time, such as whether the candidate is generally compatible or incompatible with many donor offers based on blood type or body size. Waiting time in a given local area may reflect particular characteristics in that area's recipient population that are not common to other areas. The national allocation system cannot and does not make any distinction of candidate priority based on wealth, celebrity or other purely social characteristics.
In recent years, approximately 6,500 liver transplants have been performed annually in the United States. Today more than 15,000 men, women and children continue to await this lifesaving gift. We hope the current attention generated by news reports will remind the public of the continuing need of all transplant candidates, and of the opportunity to end their wait through making a positive commitment to organ donation.