Epidemiology and natural history of primary biliary cirrhosis in a US community

Background & Aims: The epidemiology of primary biliary cirrhosis (PBC) has not been studied systematically in the United States. We report the inciden ce and prevalence of this condition in the general population. We also exam ined the validity of the Mayo natural history model for PBC among these uns elected patients from the community. Methods: The Rochester Epidemiology Pr oject entails a computerized index of diagnoses from the health care encoun ters of residents of Olmsted County, Minnesota. For potential cases identif ied using this database, the complete (inpatient and outpatient) medical re cords were reviewed to verify the diagnosis and extract information necessa ry for the application of the Mayo model. We estimated the incidence and pr evalence of PBC in this population and compared the actual survival of pati ents with PBC in the community with the survival predicted for PBC patients by the Mayo natural history model. Results: The age-adjusted (to 1990 U.S. whites) incidence of PBC per 100,000 person-years for years 1975-1995 was 4.5 (95% confidence interval [CI], 3.1-5.9) for women, 0.7 (95% CI, 0.1-1.3 ) for men, and 2.7 (95% CI, 1.9-3.5) overall. The age- and sex-adjusted pre valence per 100,000 persons as of 1995 was 65.4 (95% CI, 43.0-87.9) for wom en, 12.1 (95% CI, 1.1-23.1) for men, and 40.2 (95% CI, 27.2-53.1) overall. The Mayo natural history model accurately predicted the actual survival of these patients. Conclusions: This first description of the epidemiology of PBC in the United States indicates that its incidence and prevalence in thi s country ave among the highest reported. Outcomes among these unselected p atients from a community population further validated the Mayo natural hist ory model of PBC.