Roberts, whose research includes developing mathematical models for efficient treatment, explained that regions are used by local organ-procurement organizations (OPOs) to provide livers to recipients in other parts of the country if recipients are not available at the local level. But the national regions were not developed scientifically or with efficiency in mind. In the end, livers are wasted, he said.
In some cases, dense populations supply and draw from rural areas that have neither the requisite need for nor stock of donor livers. For instance, Seattle is the largest city in the region covering the entire Pacific Northwest, plus Hawaii and Alaska. Oklahoma is paired only with Texas, which has more than six times the population. At the same time, large population centers such as New York City and New Jersey that could easily support each other are in separate regions, while a swath of countryside in the Great Plains states has no large city handy.
To determine the most efficient regional arrangements, the Pitt researchers plugged procurement data from OPOs nationwide into an optimization model they developed called an integer program that considered more than a trillion configurations before finally deciding on the two most efficient, Schaefer said.
Illustrations of the current regional breakdown and both Pitt rearrangements are available on Pitt's Web site at www.news.pitt.edu/news/Schaefer-donor-liver-redesign.
Both Pitt models basically break the Eastern United States into four proportioned population clustersNew England, New York City-New Jersey, the Southeast, and the Rust Beltwhile the Western states form two expa
|Contact: Morgan Kelly|
University of Pittsburgh