Epidemiology of the rheumatic diseases.

Epidemiologic studies of rheumatic diseases can be broadly divided into those that describe the occurrence of specific disorders, those that attempt to quantify the role of putative risk factors for disease occurrence, and those that define the outcome and factors associated with it. Studies in this area have tended to be hypothesis testing rather than generating new etiologic or related hypotheses. In contrast to many previously published studies, more recent work has been both substantive in size and focused more on true community-based studies with the consequence that estimates of occurrence in risk obtained are likely to reflect more accurately the true nature of any associations observed.