Reduced Access to Liver Transplantation in Women: Role of Height, MELD Exception Scores, and Renal Function Underestimation

Background Sex-based disparities in liver transplantation (LT) are incompletely understood. We assessed the role of height, Model for End-Stage Liver Disease (MELD), MELD-Na, and exception points in the disparate access to LT. Methods Adults waitlisted for LT at Organ Procurement and Transplantation Network between 2002 and 2013 were included. Covariates associated with likelihood of LT were analyzed by Cox proportional model. In a separate cohort of waitlisted adults with glomerular filtration rate measurement by iothalamate clearance (n = 611), we determined the number of creatinine-derived MELD points in men versus women, across all ranges of glomerular filtration rate. The impact of correcting the MELD score deficit in women on LT was modeled. Results Among 90 720 Organ Procurement and Transplantation Network registrants, women had higher mortality than men (4 years after listing: 22% vs 18%, P < 0.0001), and lower likelihood of LT (49% vs 58%, P < 0.0001); women were 20% less likely to be transplanted (hazard ratio, 0.80; 95% confidence interval, 0.78-0.81). Differences in height and MELD exception scores accounted for most of the LT deficit in women (hazard ratio, 0.91; 95% confidence interval, 0.89-0.94). Women received between 1 and 2.4 fewer creatinine-derived MELD points than men with similar renal dysfunction. MELD-Na worsened the gender disparity. Addition of 1 or 2 MELD points to women significantly impacted LT access. Conclusions Differences in height and MELD exception points explained most of the sex-based disparity in LT. Additionally, MELD score underestimated disease severity in women by up to 2.4 points and MELD Na exacerbated this disparity. The degree of underestimation based on MELD had significant impact on allocation.