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. 2019 Oct;103(10):2113-2120.
doi: 10.1097/TP.0000000000002643.

Geographic Disparity in Deceased Donor Liver Transplant Rates Following Share 35

Mary G Bowring  1 , Sheng Zhou  1 , Eric K H Chow  1 , Allan B Massie  1   2 , Dorry L Segev, Sommer E Gentry  1   3
Affiliations

Geographic Disparity in Deceased Donor Liver Transplant Rates Following Share 35

Mary G Bowring et al. Transplantation. 2019 Oct.

Abstract

Background: The Organ Procurement and Transplantation Network implemented Share 35 on June 18, 2013, to broaden deceased donor liver sharing within regional boundaries. We investigated whether increased sharing under Share 35 impacted geographic disparity in deceased donor liver transplantation (DDLT) across donation service areas (DSAs).

Methods: Using Scientific Registry of Transplant Recipients June 2009 to June 2017, we identified 86 083 adult liver transplant candidates and retrospectively estimated Model for End-Stage Liver Disease (MELD)-adjusted DDLT rates using nested multilevel Poisson regression with random intercepts for DSA and transplant program. From the variance in DDLT rates across 49 DSAs and 102 programs, we derived the DSA-level median incidence rate ratio (MIRR) of DDLT rates. MIRR is a robust metric of heterogeneity across each hierarchical level; larger MIRR indicates greater disparity.

Results: MIRR was 2.18 pre-Share 35 and 2.16 post-Share 35. Thus, 2 candidates with the same MELD in 2 different DSAs were expected to have a 2.2-fold difference in DDLT rate driven by geography alone. After accounting for program-level heterogeneity, MIRR was attenuated to 2.10 pre-Share 35 and 1.96 post-Share 35. For candidates with MELD 15-34, MIRR decreased from 2.51 pre- to 2.27 post-Share 35, and for candidates with MELD 35-40, MIRR increased from 1.46 pre- to 1.51 post-Share 35, independent of program-level heterogeneity in DDLT. DSA-level heterogeneity in DDLT rates was greater than program-level heterogeneity pre- and post-Share 35.

Conclusions: Geographic disparity substantially impacted DDLT rates before and after Share 35, independent of program-level heterogeneity and particularly for candidates with MELD 35-40. Despite broader sharing, geography remains a major determinant of access to DDLT.

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Conflict of interest statement

DISCLOSURE

The authors declare no conflicts of interest. The data reported here have been supplied by the Minneapolis Medical Research Foundation (MMRF) as the contractor for the Scientific Registry of Transplant Recipients (SRTR). The interpretation and reporting of these data are the responsibility of the authors and in no way should be seen as an official policy of or interpretation by the SRTR, UNOS/OPTN, or the US Government.

Figures

Figure 1.
Figure 1.. (A) DSA-specific DDLT rates before and after Share 35 and (B) change in DSA-specific DDLT rates after Share 35 by OPTN region.
Each dot represents a DSA. Twenty-six DSAs experienced a decrease and 23 experienced an increase in DDLT rate after Share 35. Figure 1a x- and y-axes are on log scale so that small differences at lower DDLT rates can be better observed. Figure 2 illustrates that changes in DDLT rate at the DSA-level after Share 35 varied within and across regions.
Figure 2.
Figure 2.. MELD-adjusted deceased-donor liver transplant (DDLT) rates per person-year in each Donation Service Area pre- and post-Share 35.
DDLT rates per person-year calculated for candidates with allocation MELD 35-37. DSAs were excluded (white) if they did not have a liver transplant program during the study period (n=6) or included only programs with low transplant volume (n=3).
Figure 3.
Figure 3.. Program-specific DDLT rates in the 4 years after Share 35 (A) holding DSA-level variation constant and (B) after including additional variation observed at the DSA-level.
Dots connected with a dashed line are programs within the same DSA. From this figure, the variation driven by programs alone (3A) can be compared to variation driven by program and geographic location (3B).
See this image and copyright information in PMC

Comment in

References

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