Predicting the advent of ascites and other complications in primary biliary cirrhosis: a staged model approach.

BACKGROUND: Current survival models for primary biliary cirrhosis have limited precision for medium and long-term survival. Aim To describe a prognostic model for the advent of complications in primary biliary cirrhosis as the first approach to a staged prognostic model. METHODS: From an established database of 289 consecutive primary biliary cirrhosis patients referred to Royal Free Hospital over 12 years (mean follow-up of 4.1 years), baseline characteristics at referral were evaluated by Cox-proportional hazards regression modelling. RESULTS: The following complications occurred de novo: 85 ascites/peripheral oedema, 40 oesophagogastric varices, 63 encephalopathy, 29 spontaneous bacterial peritonitis and/or septicaemia, 59 symptomatic urinary tract infections. Age, albumin, log(10)(bilirubin), presence of ascites at referral, variceal bleeding within 6 weeks before referral, detection of oesophagogastric varices at or before referral were significant at multivariate analysis with different combinations and coefficients for each complication. The model for predicting ascites and/or peripheral oedema best fitted the observed data (ROC = 0.7682, S.E. = 0.0385). CONCLUSIONS: The known prognostic factors in primary biliary cirrhosis also model the advent of complications. In view of the prognostic importance of ascites and its more robust statistical model, ascites and/or peripheral oedema could represent, following validation, the most suitable staged model in primary biliary cirrhosis to improve precision in survival modelling.