Wait-list mortality of young patients with Biliary atresia: Competing risk analysis of a eurotransplant registry-based cohort

Liver transplantation (LT) is the standard treatment for biliary atresia (BA) patients with end-stage liver disease. The prognosis after LT has steadily improved, but overall prognosis of BA patients is also determined by mortality before LT. We aimed to quantify mortality in young BA patients on the Eurotransplant waiting list and to determine the effect of disease severity and age at time of listing on pretransplant mortality. We used a cohort study design, which incorporated data from the Eurotransplant registry. Participants were 711 BA patients who were below 5 years of age from 5 countries and listed for LT between 2001 and 2014. We applied a competing risk analysis to evaluate simultaneously the outcomes death, LT, and still waiting for a suitable organ. We used Cox proportional hazards regression to assess 2-year mortality. In a subcohort of 416 children, we performed multivariate analyses between 2-year mortality and disease severity or age, each at listing. Disease severity at listing was quantified by the Model for End-Stage Liver Disease (MELD) score, which assesses bilirubin, creatinine, albumin, and international normalized ratio as continuous variables. Two-year wait-list mortality was 7.9%. Age below 6 months and MELD score above 20 points, each at listing, were strongly and independently associated with 2-year mortality (each P < 0.001). A total of 21% of infants who fulfilled both criteria did not survive the first 6 months on the waiting list. In conclusion, our findings quantify mortality among young BA patients on the waiting list and the relative importance of risk factors (age and severity of disease at listing). Our results provide both an evidence base to rationally address high mortality in subgroups and a methodology to assess effects of implemented changes, for example, in allocation rules. Liver Transplantation 24 810-819 2018 AASLD.