title: A methodological framework for optimally reorganizing liver transplant regions.
abstract: BACKGROUND
  The United States is divided currently into 11 transplant regions, which vary in area and number of organ procurement organizations (OPOs). Region size affects organ travel time and organ viability at transplant.
  
  
  OBJECTIVE
  To develop a methodologic framework for determining optimal configurations of regions maximizing transplant allocation efficiency and geographic parity.
  
  
  METHODS
  An integer program was designed to maximize a weighted combination of 2 objectives: 1) intraregional transplants, 2) geographic parity-maximizing the lowest intraregional transplant rate across all OPOs. Two classes of functions relating liver travel time to liver viability were also examined as part of the sensitivity analyses.
  
  
  RESULTS
  Preliminary results indicate that reorganizing regions, while constraining their number to 11, resulted in up to 17 additional transplants/year depending on the travel-viability function; when not constrained, it resulted in up to 18/year of increase.
  
  
  CONCLUSIONS
  Our analysis indicates that liver transplantation may benefit through region reorganization. The analytic method developed here should be applicable to other organs and sets of organs.
authors.affiliation: Department of Radiology & Department of Medicine, Massachusetts General Hospital, Harvard Medical School, Boston 02114, USA. James@mgh-ita.org
authors.forename: James E
authors.initials: JE
authors.lastname: Stahl
authors.forename: Nan
authors.initials: N
authors.lastname: Kong
authors.forename: Steven M
authors.initials: SM
authors.lastname: Shechter
authors.forename: Andrew J
authors.initials: AJ
authors.lastname: Schaefer
authors.forename: Mark S
authors.initials: MS
authors.lastname: Roberts
mesh_terms: D006801:Humans; D007676:Kidney Failure, Chronic / Q000453:epidemiology* / Q000401:mortality / Q000601:surgery; D016031:Liver Transplantation; D012040:Regional Health Planning / Q000379:methods*; D009927:Tissue and Organ Procurement; D014481:United States / Q000453:epidemiology