Incidence of Primary Biliary Cholangitis in a Rural Midwestern Population.

BACKGROUND

Primary biliary cholangitis (PBC) is a rare disease with incidence that varies with time and geography. Only two studies have assessed PBC incidence in the United States, with the most recent appearing over a decade ago. The objective of the present study was to assess PBC incidence in the United States in a more recent era.

METHODS

The incidence of PBC was assessed in a population-based cohort in rural, Midwestern Wisconsin over two decades spanning from June 1992 through June 2011. Cases were initially identified in the electronic medical record and then manually verified for inclusion according to the American Association for the Study of Liver Disease criteria for PBC. Additional data were abstracted for verified cases.

RESULTS

A total of 79 cases of PBC were identified over the 20-year period for an overall age- and sex-standardized incidence of 4.9 cases per 100,000 person-years. Incidence was higher in females, but changes over time were not significant. After a mean 7.3 years follow-up, all-cause mortality of those with PBC was 29%, and estimated 10-year survival was 76%.

CONCLUSIONS

The overall incidence of PBC in a Midwestern population of the United States has remained relatively stable over the last two decades. Patients have better prognosis, and the survival of PBC cases has improved.