Validation of gender-equity model for liver allocation and its sodium variant in candidates for liver transplantation

Background The current allocation system for liver transplantation (LT) is based on the sickest-first policy, using objective variables to ensure equal priority. However, under-prioritization of female patients for LT, compared to males, is well demonstrated and new scores have been proposed to overcome this systematic bias. This study evaluated the ability of these new scores to predict the long-term outcomes of patients with cirrhosis. Methods The clinical and laboratory characteristics of 694 consecutive candidates for liver transplantation from 2 liver transplant centers were recorded. The model for end-stage liver disease (MELD)-based scores (MELD, MELD-Sodium and MELD 3.0), as well as the Gender-Equity Model for liver Allocation (GEMA) and GEMA-Sodium, were used to assess the severity of liver disease. Patients were followed-up prospectively and their outcomes assessed. Results During a follow-up period of median length 12 months (range: 4-52), 28.5% of patients died, 21% of patients underwent LT, while 50.5% remained alive. Female patients had significantly lower MELD and MELD-Sodium scores compared to males, attributable to their significantly lower creatinine, while MELD 3.0, GEMA and GEMA-Sodium did not differ between the 2 sexes. In multivariate Cox regression analysis, GEMA-Sodium was the only factor independently associated with death/LT, and showed very good discriminative ability (hazard ratio 1.10, 95% confidence interval 1.073-1.128; P<0.001). These findings were confirmed in several subgroup analyses. Conclusions Our findings show for the first time the predictive ability of GEMA-Sodium for the long-term outcomes of LT candidates. However, further studies are needed to confirm these findings.