The epidemiology and natural history of primary biliary cirrhosis: a nationwide population-based study

Very few population-based studies exist on the epidemiology of primary biliary cirrhosis (PBC), and none have been conducted in the last decade. We aimed to determine the epidemiology and prognosis of PBC over the past two decades.

Patients were identified by multiple case finding strategies, covering the total population of Iceland. A search was conducted in the centralized database of antimitochondrial antibody (AMA) measurements and computerized diagnosis and pathological registries. All AMA measurements taken in Iceland between 1991 and 2010 were analyzed. Relevant clinical information was gathered from medical records, pathology reports, and death certificates. Incidence was compared between two periods, 1991-2000 versus 2001-2010.

A total of 168 patients were identified, of which 138 were female (82%), with a median age 62 years (range 13-92). Prevalence at the end of the study period was 38.3 cases per 100 000 person-years. Age-standardized incidence for female patients during the first period was 3.4 versus 4.1 during the second (NS) and that for male patients was 0.6 during the first period versus 1.0 per 100 000 during the second (NS). Overall incidence in the first period was 2.0 and that in the second was 2.5 per 100 000 (NS). Stage III-IV liver fibrosis was present in 28% of patients at diagnosis with no significant differences between the two decades. Median survival after diagnosis was 15 years. Five patients underwent liver transplantation.

The incidence and prevalence figures of PBC in Iceland are among the highest reported and have been stable over the last two decades. The prognosis of patients in this population-based cohort is better than that previously reported.