# Geographic Variation in Non-HCC MELD Exceptions and Its Effect on Liver Transplant Waitlist Outcomes

> **NIH NIH K08** · UNIVERSITY OF ALABAMA AT BIRMINGHAM · 2022 · $160,775

## Abstract

Summary: Geographic variation in model for end stage liver disease (MELD) scores at transplant across
donation service areas has fueled a major policy debate over allocation of donor livers. An important caveat to
this perceived disparity is the focus on allocation MELD, in which patients with lower calculated MELD scores
may be assigned a higher score if their calculated MELD is thought to underestimate the risk of waitlist
mortality. Analysis of calculated MELD at transplant demonstrates much less variation between regions. Some
high allocation MELD regions actually have low calculated MELD scores relative to the rest of the country. The
different pictures painted by allocation versus calculated MELD scores highlight the critical role MELD
exception points play in geographic differences in access to transplantation. A national liver review board was
recently implemented to impose national standardization of MELD exception scores in an effort to mitigate
geographic disparity. A potential flaw in this strategy is the assumption that the risk of mortality associated with
a given MELD score or exception diagnosis is the same across geographic areas. We know that social
determinants of health and access to care vary widely across the country, however, and that these differences
have a significant impact on health outcomes. Imposing a geographically uniform MELD exception scoring
policy that does not account for these important differences may have the unintended effect of overestimating
the risk of waitlist mortality for exception patients in some regions while underestimating that risk in others, thus
worsening geographic disparity rather than mitigating it. I hypothesize that significant geographic variation
exists in the prevalence and appropriateness of MELD exceptions scores at the county level, and that
appropriate adjustment to MELD exception scores based on a candidate’s location will mitigate geographic
disparity in liver transplant waitlist mortality. Despite abundant literature on geographic disparity in liver
transplantation, few studies actually apply formal geospatial analysis to geographically based questions facing
the field. I propose to utilize such techniques to accomplish the following unique aims: (1) determine the
prevalence and appropriateness of MELD exceptions on a county level and diagnose the presence of
geographic clusters where these exceptions provide an inappropriate advantage to transplant candidates with
MELD exception scores; (2) determine adjusted MELD exception scores which would equalize waitlist mortality
risk between exception and non-exception patients in each geographic area; and (3) simulate waitlist outcomes
under an alternative allocation scenario where MELD exception points are assigned according to geographic
region as determined in Aim 2. This study will provide a more granular and personalized approach to the
estimation of waitlist mortality. The mentoring and training afforded by this award will foste...

## Key facts

- **NIH application ID:** 10404579
- **Project number:** 5K08DK125769-02
- **Recipient organization:** UNIVERSITY OF ALABAMA AT BIRMINGHAM
- **Principal Investigator:** Robert M. Cannon
- **Activity code:** K08 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2022
- **Award amount:** $160,775
- **Award type:** 5
- **Project period:** 2021-06-01 → 2026-03-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10404579

## Citation

> US National Institutes of Health, RePORTER application 10404579, Geographic Variation in Non-HCC MELD Exceptions and Its Effect on Liver Transplant Waitlist Outcomes (5K08DK125769-02). Retrieved via AI Analytics 2026-05-24 from https://api.ai-analytics.org/grant/nih/10404579. Licensed CC0.

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