Sex and body size disparities under MELD 3.0: Evaluation of persisting gaps in liver transplant access

BACKGROUND: The July 2023 implementation of MELD3.0 aimed to address longstanding sex disparities in liver transplant access. However, its impact has been understudied. METHODS: We analyzed US transplant registry data (February 4, 2020-September 30, 2024) among adult candidates for liver transplant. Using a difference-in-differences design, we assessed the impact of MELD3.0 during immediate and 3-month postimplementation ("burn-in") periods on receipt of (1) a top 5 organ offer or (2) transplant. Poisson and logistic models estimated the offer and transplant probabilities. Mediation and subgroup analyses by height were also conducted. RESULTS: We analyzed 9,952,473 person-day observations from 60,159 candidates for liver transplant. Following MELD3.0, women had greater relative increases in top 5 organ offer rates (rate ratio: 1.14 1.25 1.37 at implementation; rate ratio: 1.11 1.16 1.22 at 3 mo). Pre-MELD3.0, transplant rates were lower for women than men (OR: 0.84 0.86 0.89 ). Post policy, women had greater relative improvements in transplant access than men (OR: 1.16 1.36 1.60 at implementation; OR: 1.09 1.18 1.29 at 3 mo), but this advantage diminished over time, with the model-estimated improvement for women relative to men declining to OR 0.81 by the study end. In mediation analysis, adjustment for height eliminated the difference in transplant rates by sex (OR: 0.98 1.01 1.05 ). Among taller (≥166 cm) candidates, baseline differences by sex persisted (OR: 0.89 0.92 0.96 ), but not in the shorter (<166 cm) group (OR: 0.92 0.97 1.03 ). Post policy, the benefit for women was more pronounced in shorter candidates (OR: 1.19 1.47 1.83 ). CONCLUSIONS: MELD3.0 led to early gains in transplant access for women, though this effect diminished over time and differences by sex mediated by body size persisted.