Height contributes to the gender difference in wait-list mortality under the MELD-based liver allocation system

Abstract

This study examined factors associated with the gender disparity in wait-list mortality in the MELD era. Adult patients listed for liver transplantation from 2002 to 2008 were included. Females [12 585(36%)] and males [22 126(64%)] differed clinically by age (54 vs. 52 years), height (1.6 vs. 1.8 m), listing estimated glomerular filtration rate [(eGFR); 70 vs. 83 mL/min] and cirrhosis etiology. Holding MELD constant, females were at 19% (95% CI, 1.13-1.25, p < 0.001) higher risk of wait-list mortality than males under the current allocation system. The relative hazard increased with worsening renal function, whether measured by serum creatinine or eGFR. Adjustment for MELD, age, African-American race, cirrhosis etiology, region and ABO group attenuated this relative hazard (HR 1.16; 95% CI, 1.10-1.22; p < 0.001) but additional adjustment for height completely explained this gender disparity in wait-list mortality (HR 1.05; 95% CI, 0.98-1.12; p = 0.2). Transplantation rates, however, remained lower among females, even after adjustment for height (HR 0.88; 95% CI, 0.82-0.92; p < 0.001). In conclusion, under the current liver allocation system, women have a 19% increased risk of wait-list mortality compared to men with the same MELD scores. Height contributes to this gender disparity, possibly reflecting differences in transplantation rates for shorter individuals.