Performance of the gender-equity model for liver allocation (GEMA-Na) within the first 30 and 60 days of listing

Abstract

Background: Models for liver transplant (LT) allocation have been trained to predict mortality or delisting for sickness at 90 days. Their performance in a context of waiting list shortening is uncertain. Methods: Retrospective study of two cohorts of patients enlisted for LT in the UK (2010-2020) and Australia (1997-2020). Mortality or delisting for sickness within the first 30 and 60 days was evaluated. Harrell’s c statistics (Hc) were used to assess discrimination. Results: In all, 7,133 patients from the UK (33% women) and 1,638 patients from Australia (26.4% women) were included. Mortality or delisting for sickness at 30 and 60 days were 2.6% and 4.5% in the UK, and 2.7% and 4.6% in Australia. In the UK at 30 days, GEMA-Na obtained the highest discrimination (Hc=0.818; 95%CI 0.783-0.853), followed by MELD-Na (Hc=0.796; 95%CI 0.759-0.834; p=0.004), and MELD 3.0 (Hc=0.782; 95%CI 0.743-0.821; p<0.001). In Australia at 30 days, the most accurate forecasts came from GEMA-Na (Hc=0.832; 95%CI 0.770-0.894), followed by MELD 3.0 (Hc=0.805; 95%CI 0.737-0.872; p=0.030), and MELD-Na (Hc=0.789; 95%CI 0.717-0.861; p=0.018). The discrimination benefit of GEMA-Na at 30 days was more pronounced in women: Hc=0.824 (95%CI 0.767-0.822) in the UK, and Hc=0.856 (95%CI 0.768-0.944) in Australia. Results were similar at 60 days. Differential prioritization at 30 days occurred in 15% of patients when comparing GEMA-Na vs MELD-Na, and in 15.3% of patients when comparing GEMA-Na vs MELD 3.0. Patients differently prioritized by GEMA-Na over MELD-Na had higher risk of the outcome at 30 days (OR=2.5; p=0.043) and at 60 days (OR=4.2; p=0.005). Patients differently prioritized by GEMA-Na over MELD 3.0 had increased likelihood of the outcome at 30 days (OR=7.3; p=0.009) and at 60 days (OR=3.8; p=0.004). Conclusions: GEMA-Na outperformed MELD-Na and MELD 3.0 to predict mortality in a context of waiting list shortening and it could obviate gender-disparities for accessing LT.

Publication
2023 Joint International Congress of ILTS, ELITA and LICAGE