Cholesterol gallstones: from epidemiology to prevention

Gallstones are a major public health problem in all developed countries. Many epidemiological studies have been performed with the aim of establishing gallstone prevalence and incidence rates, and of defining risk factors, amenable to prevention. Cholesterol gallstones constitute more than 80% of stones in the Western world. The data usually employed in assessing gallstone prevalence were derived until recently from selected series of patients (necropsies, surgery, etc), which may not represent the general population. Suffice to say that the reported 0% prevalence of gallstones in the Masaï population was deduced from surgical experience in that area, which is far from being an ideal way to collect epidemiological data. Necropsy studies are subject to selection bias, which can be reduced by adjusting the data by standardisation. Necropsy studies have shown that, even after standardisation for age and sex, there are major differences between different countries (table 1). The available necropsy data, scrutinising longer intervals of time, decades1,2 or even a century,3 have revealed a trend of increasing gallstone prevalence.