title: Addressing geographic disparities in liver transplantation through redistricting.
abstract: Severe geographic disparities exist in liver transplantation; for patients with comparable disease severity, 90-day transplant rates range from 18% to 86% and death rates range from 14% to 82% across donation service areas (DSAs). Broader sharing has been proposed to resolve geographic inequity; however, we hypothesized that the efficacy of broader sharing depends on the geographic partitions used. To determine the potential impact of redistricting on geographic disparity in disease severity at transplantation, we combined existing DSAs into novel regions using mathematical redistricting optimization. Optimized maps and current maps were evaluated using the Liver Simulated Allocation Model. Primary analysis was based on 6700 deceased donors, 28 063 liver transplant candidates, and 242 727 Model of End-Stage Liver Disease (MELD) changes in 2010. Fully regional sharing within the current regional map would paradoxically worsen geographic disparity (variance in MELD at transplantation increases from 11.2 to 13.5, p = 0.021), although it would decrease waitlist deaths (from 1368 to 1329, p = 0.002). In contrast, regional sharing within an optimized map would significantly reduce geographic disparity (to 7.0, p = 0.002) while achieving a larger decrease in waitlist deaths (to 1307, p = 0.002). Redistricting optimization, but not broader sharing alone, would reduce geographic disparity in allocation of livers for transplant across the United States.
authors.affiliation: Department of Surgery, Johns Hopkins University School of Medicine, Baltimore, MD, USA.
authors.forename: S E
authors.initials: SE
authors.lastname: Gentry
authors.forename: A B
authors.initials: AB
authors.lastname: Massie
authors.forename: S W
authors.initials: SW
authors.lastname: Cheek
authors.forename: K L
authors.initials: KL
authors.lastname: Lentine
authors.forename: E H
authors.initials: EH
authors.lastname: Chow
authors.forename: C E
authors.initials: CE
authors.lastname: Wickliffe
authors.forename: N
authors.initials: N
authors.lastname: Dzebashvili
authors.forename: P R
authors.initials: PR
authors.lastname: Salvalaggio
authors.forename: M A
authors.initials: MA
authors.lastname: Schnitzler
authors.forename: D A
authors.initials: DA
authors.lastname: Axelrod
authors.forename: D L
authors.initials: DL
authors.lastname: Segev
mesh_terms: D058625:End Stage Liver Disease / Q000628:therapy*; D005843:Geography; D006301:Health Services Needs and Demand / Q000458:organization & administration; D054625:Healthcare Disparities; D006801:Humans; D016031:Liver Transplantation; D014019:Tissue Donors / Q000600:supply & distribution*; D009927:Tissue and Organ Procurement / Q000458:organization & administration*; D014850:Waiting Lists
keywords: Broader sharing; Liver Simulated Allocation Model; geographic disparities; liver allocation