The study assessed the incidence and prevalence of primary biliary cirrhosis (PBC) in the United States general population.
The validity of the Mayo natural history model for PBC among these unselected patients from the community was also examined, and the findings were reported in this month's Gastroenterology.
Potential cases were identified from a database of diagnoses from the health-care encounters of residents of Olmsted County, Minnesota. The complete (inpatient and outpatient) medical records were reviewed to verify the diagnosis and extract information necessary for the application of the Mayo model.
The researchers estimated the incidence and prevalence of PBC in the population. They also compared the actual survival of patients with PBC in the community with the survival predicted for PBC patients by the Mayo natural history model.
The team found that the age-adjusted (to 1990 US whites) incidence of PBC per 100,000 person-years, for years 1975-1995, was 4.5 for women, 0.7 for men, and 2.7 overall.
Prevalence of PBC per 100,000 persons in 1995:
The age- and sex-adjusted prevalence per 100,000 persons as of 1995 was 65.4 for women, 12.1 for men, and 40.2 overall.
The Mayo natural history model accurately predicted the actual survival of these patients.
Researcher Keith Lindor concluded, "This first description of the epidemiology of PBC in the United States indicates that its incidence and prevalence in this country are among the highest reported. Outcomes among these unselected patients from a community population further validated the Mayo natural history model of PBC."