title: Geographic inequities in liver allograft supply and demand: does it affect patient outcomes?
abstract: BACKGROUND
  Significant geographic inequities mar the distribution of liver allografts for transplantation.
  
  
  METHODS
  We analyzed the effect of geographic inequities on patient outcomes. During our study period (January 1 through December 31, 2010), 11,244 adult candidates were listed for liver transplantation: 5,285 adult liver allografts became available, and 5,471 adult recipients underwent transplantation. We obtained population data from the 2010 United States Census. To determine the effect of regional supply and demand disparities on patient outcomes, we performed linear regression and multivariate Cox regression analyses.
  
  
  RESULTS
  Our proposed disparity metric, the ratio of listed candidates to liver allografts available varied from 1.3 (region 11) to 3.4 (region 1). When that ratio was used as the explanatory variable, the R(2) values for outcome measures were as follows: 1-year waitlist mortality, 0.23 and 1-year posttransplant survival, 0.27. According to our multivariate analysis, the ratio of listed candidates to liver allografts available had a significant effect on waitlist survival (hazards ratio, 1.21; 95% confidence interval, 1.04-1.40) but was not a significant risk factor for posttransplant survival.
  
  
  CONCLUSIONS
  We found significant differences in liver allograft supply and demand--but these differences had only a modest effect on patient outcomes. Redistricting and allocation-sharing schemes should seek to equalize regional supply and demand rather than attempting to equalize patient outcomes.
authors.affiliation: 1 Division of Abdominal Transplantation, Baylor College of Medicine, Houston, TX. 2 Division of Nephrology and Hypertension, University of Kansas, Kansas City, KS. 3 Department of Internal Medicine, University of Arizona, Tucson, AZ. 4 Department of Abdominal Transplantation, University of Arizona, Tucson, AZ. 5 College of Public Health, University of Arizona, Tucson, AZ.
authors.forename: Abbas
authors.initials: A
authors.lastname: Rana
authors.forename: Bruce
authors.initials: B
authors.lastname: Kaplan
authors.forename: Irbaz B
authors.initials: IB
authors.lastname: Riaz
authors.forename: Marian
authors.initials: M
authors.lastname: Porubsky
authors.forename: Shahid
authors.initials: S
authors.lastname: Habib
authors.forename: Horacio
authors.initials: H
authors.lastname: Rilo
authors.forename: Angelika C
authors.initials: AC
authors.lastname: Gruessner
authors.forename: Rainer W G
authors.initials: RW
authors.lastname: Gruessner
mesh_terms: D000293:Adolescent; D000328:Adult; D064591:Allografts / Q000600:supply & distribution*; D005260:Female; D005843:Geography; D054625:Healthcare Disparities; D006801:Humans; D016014:Linear Models; D017093:Liver Failure / Q000453:epidemiology* / Q000601:surgery*; D016031:Liver Transplantation / Q000706:statistics & numerical data*; D008297:Male; D008875:Middle Aged; D016016:Proportional Hazards Models; D012307:Risk Factors; D009927:Tissue and Organ Procurement; D014184:Transplantation, Homologous / Q000379:methods; D016896:Treatment Outcome; D014481:United States; D014850:Waiting Lists; D055815:Young Adult