Estimates of the prevalence of selected arthritic and musculoskeletal diseases in the United States.

The National Arthritis Data Workgroup focused its studies primarily on joint disease with the addition of osteoporosis which is a frequently occurring musculoskeletal condition and public health problem. We used national data sets as well as published studies to estimate prevalence in the United States. We report on prevalence rather than incidence because of the difficulty in defining the point of onset and because primary national data sources currently available are concerned with disease prevalence.