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. 2019 Jul;19(7):2044-2052.
doi: 10.1111/ajt.15297. Epub 2019 Mar 18.

Geographic disparities in liver supply/demand ratio within fixed-distance and fixed-population circles

Christine E Haugen  1 , Tanveen Ishaque  1 , Abel Sapirstein  1 , Alexander Cauneac  1 , Dorry L Segev  1   2   3 , Sommer Gentry  1   4
Affiliations

Geographic disparities in liver supply/demand ratio within fixed-distance and fixed-population circles

Christine E Haugen et al. Am J Transplant. 2019 Jul.

Abstract

Recent OPTN proposals to address geographic disparity in liver allocation have involved circular boundaries: the policy selected 12/17 allocated to 150-mile circles in addition to DSAs/regions, and the policy selected 12/18 allocated to 150-mile circles eliminating DSA/region boundaries. However, methods to reduce geographic disparity remain controversial, within the OPTN and the transplant community. To inform ongoing discussions, we studied center-level supply/demand ratios using SRTR data (07/2013-06/2017) for 27 334 transplanted deceased donor livers and 44 652 incident waitlist candidates. Supply was the number of donors from an allocation unit (DSA or circle), allocated proportionally (by waitlist size) to the centers drawing on these donors. We measured geographic disparity as variance in log-transformed supply/demand ratio, comparing allocation based on DSAs, fixed-distance circles (150- or 400-mile radius), and fixed-population (12- or 50-million) circles. The recently proposed 150-mile radius circles (variance = 0.11, P = .9) or 12-million-population circles (variance = 0.08, P = .1) did not reduce the geographic disparity compared to DSA-based allocation (variance = 0.11). However, geographic disparity decreased substantially to 0.02 in both larger fixed-distance (400-mile, P < .001) and larger fixed-population (50-million, P < .001) circles (P = .9 comparing fixed distance and fixed population). For allocation circles to reduce geographic disparities, they must be larger than a 150-mile radius; additionally, fixed-population circles are not superior to fixed-distance circles.

Keywords: Organ Procurement and Transplantation Network (OPTN); clinical research/practice; donors and donation: deceased; liver transplantation/hepatology; organ allocation.

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Conflict of interest statement

Disclosure

Authors have no conflict of interest to report as described by American Journal of Transplantation.

Figures

Figure 1.
Figure 1.
Fixed-distance circles surrounding each transplant center (red triangles) and donor hospital (black triangle) showing the weighted portion of donor liver supply from the donor hospital based the transplant center waitlist size (demand).
Figure 2.
Figure 2.
Fixed-distance (150-mile, 400-mile) and fixed-population (12-million, 50-million) circles around transplant centers CAPC (Stanford), MABI (Beth Israel), LATU (Tulane), WICH (University of Wisconsin).
Figure 3.
Figure 3.
Supply/demand ratio under current donor service area (DSA) allocation.
Figure 4.
Figure 4.
Supply/demand ratio for (a) 150-mile fixed-distance and (b) 12-million fixed-population circle.
Figure 5.
Figure 5.
Supply/demand ratio within (a) 400-mile fixed-distance and (b) 50-million fixed-population circles.
See this image and copyright information in PMC

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