Alternative Methods for Defining Osteoarthritis and the Impact on Estimating Prevalence in a US Population‐Based Survey

The strict definition for OA (ICD-9-CM 715) excludes many individuals with OA. The probable definition of OA has the optimal combination of sensitivity and specificity relative to the 2 other MEPS-based definitions and yields a national annual estimate of 30.8 million adults with OA (13.4% of US adult population) for 2008-2011.