There is a widespread impression that the number of patients with the autoimmune liver disease primary biliary cirrhosis (PBC) is increasing, although its incidence and prevalence vary widely. Using thorough case-finding methods and rigorous definitions to assess changes in incidence and prevalence with time and to explore the symptomatology and mortality of the disease in a large group of unselected patients, we performed a descriptive epidemiological study of PBC in a well defined population over a fixed period of time using established diagnostic criteria and with clinical follow-up of all cases. In a population of 2.05 million in northern England 770 definite or probable PBC cases were identified. Prevalence rose from 201.9 per 10 6 in the adult population and 541.4 per 10 6 women over 40 in 1987 to 334.6 per 10 6 adults and 939.8 per 10 6 women over 40 in 1994. Incidence was 23 per 10 6 in 1987 and 32.2 per 10 6 in 1994. Three hundred patients died in median follow-up of 6.27 years (141 liver deaths); the standardized mortality ratio was 2.85. At presumed diagnosis, 60.9% had no symptoms of liver disease. By June 1994 62% of prevalent patients had liver symptoms. PBC is apparently increasing. It is still unclear whether this is because of a true increase, case finding, or increased disease awareness. The study draws attention to (1) high mortality from liver disease and non-liver-related causes even in patients initially with no liver symptoms and (2) apparently poor diagnostic awareness of the disease. (HEPATOLOGY 1999;30: 390-394.)
Recently interest in the autoimmune liver disease primary biliary cirrhosis (PBC) has increased considerably. 1,2 This may be attributed not only to advances in understanding of the immune mechanisms of the disease but also to increasing recognition of apparent variation in its incidence and prevalence. The tools of epidemiology may offer understanding of the true clinical spectrum of the disease as well as offering clues as to its etiology. 3 Most available data on the epidemiology of PBC has hitherto been drawn from case series. 4 The Abbreviations: PBC, primary biliary cirrhosis; AMA, antimitochondrial antibodies; LFT, liver function test; ONS, Office of National Statistics.