Predictive models of natural history in primary biliary cirrhosis.

Primary biliary cirrhosis is a slow, progressive disease. Although many years may elapse before asymptomatic primary biliary cirrhosis patients begin experiencing symptoms of liver disease, their overall survival is significantly lower than the normal population. The Mayo natural history model has been developed to depict patient survival in the absence of effective therapeutic intervention. Although there are a number of caveats in applying this model, it has been validated using external data sets and established as an accepted tool for clinical or research purposes. Furthermore, recent data suggest that the Mayo natural history model continues to provide useful, predictive information in the presence of ursodeoxycholic acid therapy, which has been shown to lower the serum bilirubin to the natural history model for patient survival. In addition to the natural history model for patient survival, mathematical models have been developed to describe histologic progression and development of esophageal varices.