Disabilities, people with definitions

OA is the most prevalent of the rheumatic diseases, and is responsible for enormous disability and loss of productivity. Prevalence increases with age, and radiographic data show that OA at some skeletal site occurs in the majority of people over 65 years of age, and in nearly everyone over 75 years of age. Despite intense epidemiologic study, the exact prevalence of OA is unknown, owing to the uncertainties and variations of diagnostic definition and reporting mechanisms. Another confounder is that many patients with radiographically apparent OA do not have symptoms that lead them to medical care. 

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