MELD 3.0 – How New Liver Transplant Allocation Priorities Have Impacted Sex Disparity

UPMC physicians and researchers participated in a multi-center study investigating the effect of the revised MELD 3.0 scoring system, which was implemented in the U.S. on 7/13/2023, and whether the inclusion of female sex as a variable altered the established disadvantage experienced by women on the transplant waiting list.

The prior allocation system has been shown to disadvantage women. Women often had lower measured creatinine and smaller body size, factors not fully accounted for in older models, resulting in lower priority despite comparable disease severity. MELD 3.0 was explicitly developed to address such limitations by adding female sex and serum albumin as variables, capping creatinine, and introducing interaction terms between bilirubin and sodium and between albumin and creatinine.

The analysis compared the probability of transplantation and death within 90 days of waiting list registration within two cohorts of adult candidates listed for liver transplantation:

1. PRE era: the year prior to implementation (7/13/2022 to 7/12/2023)
2. POST era: the first year of MELD 3.0 adoption (7/13/2023 to 7/12/2024).

Exclusions included pediatric patients (<18 years old), non-simultaneous liver-kidney multi-organ listings, status 1 listings, and those receiving exception approvals at time of listing.

There were 11,105 eligible candidates (4,276 female, 6,829 male) in the PRE era and 11,158 (5,070 female, 7,088 male) in the POST era.

Key findings

Median listing MELD 3.0 scores:

• PRE era women = 22 (interquartile range 16-31), men 20 (14-29) (p <0.01).
• POST era women = 21 (15–29), men 20 (14–29) (p <0.01).

90-day transplant probability:

• PRE era men = 51.7%, women 46.0% (p=0.001)
• POST era men = 53.8%, women 50.6% (p=0.003).

90-day survival:

• PRE era men = 93.6%, women 91.5% (p=0.003)
• POST era men = 93.2%, women 92.1% (p=0.02).

Conclusion

The implementation of MELD 3.0 has had the intended effect of narrowing the transplant probability gap between sexes, and female wait-list mortality decreased, with the data within the second half of the POST era suggesting a further decrease in disparity over time.

This evaluation indicates that the implementation of MELD 3.0 correlates with a reduced sex disparity. While women remain at somewhat higher risk of wait-list death relative to men, the degree of that disadvantage has declined, and access to transplantation within 90 days has improved for women.

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