Epidemiology of primary biliary cirrhosis.

A multi-national survey of the clinical and epidemiological aspects of primary biliary cirrhosis (PBC) has been conducted in 10 countries in Western Europe, surveying a population of over 24 million. The prevalence on 31 December, 1981 was 23/million, but this showed a marked variation from centre to centre for reasons which are not clear. The annual incidence of PBC has remained constant at about 4/million over the past 4 years, while the point prevalence has continued to rise, suggesting that the true prevalence may be rather higher than present figures suggest. The female: male sex ratio is 10:1, but in stages I & II this ratio is 6.5:1 compared with 11.4:1 in stages III & IV. Possible reasons for this are discussed.