Reuters Health Information (2007-11-19): New organ allocation criteria may reduce liver waiting list mortality
New organ allocation criteria may reduce liver waiting list mortality
Last Updated: 2007-11-19 16:00:12 -0400 (Reuters Health)
NEW YORK (Reuters Health) - A change in the way that donated livers are allocated to recipients appears to have resulted in a drop in waiting list mortality, according to a report in the November issue of the Archives of Surgery.
Since 1991, there has been a tenfold increase in the number of waiting list patients, yet the number of available donor livers only increased twofold. In 1989, a system was introduced whereby patients with end-stage liver disease were divided into four groups based on medical urgency. As the list grew, however, duration on the list became the primary way to sort patients within each category.
In 2002, a new system was introduced based on the Model for End-stage Liver Disease (MELD) score, which uses a variety of laboratory values to objectively assess disease severity. The goal of the system was to allocate donor organs based on recipient need, not on waiting time.
"Our study provides strong evidence that the adoption of the MELD-based allocation system has led to a decline in wait list mortality," lead author Dr. Mary T. Austin told Reuters Health. "Other studies support these findings but...these studies did not employ methodology that would allow them to isolate the effect of the policy change on wait list mortality."
With the MELD-based system, "it is no longer beneficial to list patients early for the sole purpose of banking time on the waiting list as organs are allocated to sicker patients first without regard to time on the list," she emphasized.
In the present study, Dr. Austin and colleagues, from Vanderbilt University Medical Center in Nashville, Tennessee, analyzed national liver transplantation data collected from March 1999 to July 2004. The study was confined to adult liver transplant candidates.
With implementation of the MELD-based system, waiting list mortality actually increased initially, from roughly 11 to 13 deaths per 1000 registrants per month. Over time, however, waiting list mortality dropped by about 0.09 deaths per 1000 registrants per month (p < 0.001).
These changes coincide with a reduction in waiting time from approximately 294 to 250 days, the report indicates (p < 0.001).
Use of the MELD-based system did not affect the number of new registrants listed per month or influence 3- and 6-month survival after transplantation.
"The allocation of donor organs is a complex and constantly evolving process," Dr. Austin concluded. "It is critical that we continue to re-evaluate our system to ensure the most equitable distribution of such a precious resource."
Arch Surg 2007;142:1079-1085.