Performance of routine risk scores for predicting cirrhosis-related morbidity in the community

Abstract

Models predicting an individual's 10-year risk of cirrhosis complications have not been developed for a community setting. Our objectives were to assess the performance of existing risk scores - both with and without genetic data - for predicting cirrhosis complications in the community. We used a 2-stage study design. In stage 1, a systematic review was conducted to identify risk scores derived from routine liver blood tests that have demonstrated prior ability to predict cirrhosis-related complication events. Risk scores identified from stage 1 were tested in a UK Biobank subgroup, comprising participants with a risk factor for chronic liver disease (stage 2). Cirrhosis complications were defined as hospitalisation for liver cirrhosis or presentation with hepatocellular carcinoma. Discrimination of risk scores with and without genetic data was assessed using the Wolbers C-index, Harrell's adequacy index, and cumulative incidence curves. Twenty risk scores were identified from the stage-1 systematic review. For stage-2, 197,509 UK biobank participants were selected. The cumulative incidence of cirrhosis complications at 10 years was 0.58%; 95% CI 0.54-0.61 (1,110 events). The top performing risk scores were aspartate aminotransferase-to-platelet ratio index (APRI: C-index 0.804; 95% CI 0.788-0.820) and fibrosis-4 index (FIB-4: C-index 0.780; 95% CI 0.764-0.795). The 10-year cumulative incidences of cirrhosis complications for participants with an APRI score exceeding the 90th, 95th and 99th percentile were 3.30%, 5.42% and 14.83%, respectively. Inclusion of established genetic risk loci associated with cirrhosis added <5% of new prognostic information to the APRI score and improved the C-index only minimally (i.e. from 0.804 to 0.809). Accessible risk scores derived from routine blood tests (particularly APRI and FIB-4) can be repurposed to estimate 10-year risk of cirrhosis morbidity in the community. Genetic data improves performance only minimally. New approaches are needed in community settings to reduce the late diagnosis of chronic liver disease. Thus, in a community cohort, we assessed the ability of 20 routine risk scores to predict 10-year risk of cirrhosis-related complications. We show that 2 routine risk scores in particular - "APRI" and "FIB-4" - could be repurposed to estimate an individual's 10-year risk of cirrhosis-related morbidity. Adding genetic risk factor information to these scores only modestly improved performance.