P150 Sex-based differences in patient outcomes and organ offers on the UK liver transplant waiting list

<h3></h3> International studies demonstrate that women are less likely to be listed for and receive a liver transplant (LT), especially since MELD prioritisation was introduced in 2002. We examined if similar disparities exist in the UK across 3 eras, defined by the introduction of the UKELD score for prioritisation in 2008 and the National Liver Offering Scheme (NLOS) in 2018. Adults registered on the NHSBT Transplant Registry for liver-only elective transplantation, from inception to end of 2023 financial year were included (24,353 candidates; 19,036 recipients) and partitioned in 3 eras (era1: pre-2008; era2: 2008–2018; era3: post-2018). The era3 registry was merged with the offers dataset, only available post-2018, and offers to re-LT and suspended candidates were excluded (9,052 total offers). No major sex disparities were seen in outcomes pre-2008, but 1-year incidence of LT was significantly lower in females in era2 and era3 (table 1). Similarly, the cumulative incidence function (CIF) of LT was not different by sex in era1 (p=0.9) while it was significantly lower in females in both era2 and era3 (both p&lt;0.001). However, after controlling for clinically relevant factors, female sex remained independently associated with lower 1-year cause-specific hazard of LT only during era2 (HR 0.919, 95% CI 0.867–0.974; p=0.005). Mortality on the list was lower in females pre-2008 (p&lt;0.01), while no significant difference was seen afterwards (p=0.2 in era2; p=0.8 in era3). Post-2018 offers analysis showed that a higher proportion of listed females received at least one named DBD offer (1–2: 33.3%F vs 30.9%M; &gt;3:18.2%F vs 16.9%M; p=0.05), however higher proportions of offers to females were declined (52%F vs 48.2%M, p=0.003). Nevertheless, similar 6-months CIF of named DBD LT between sexes was observed, while LT with centre-allocated organs (fast-track DBDs or DCDs) was significantly lower in females (p&lt;.001). While females had lower cumulative incidence of LT in eras 2 and 3, such disparity was no longer significant in era3 after risk adjustment. Offer analysis post-2018 showed similar cumulative incidence of named DBD LT by sex, despite higher proportions of offers to females being declined. In contrast, female candidates had lower cumulative incidence of centre-allocated organs. As this was the sole allocation model existing in 2008–2018, it may explain the lower cause-specific hazard for LT in females in era2 and suggests that NLOS may have mitigated some biases inherent to centre-based allocation. Further research should explore why these sex-based disparities exist and their impact on long-term survival.