Arthritis Case Definition (Adult)
Estimating Population Prevalence
For the purpose of estimating the population prevalence of arthritis, we recommend using self-reported data as the data source and using doctor-diagnosed arthritis as the case definition. Both the state-based Behavioral Risk Factor Surveillance System (BRFSS) and National Health Interview Survey (NHIS) are self-reported data surveys. A “case” of doctor-diagnosed arthritis in these surveys is defined as a “yes” answer to the following question; “Have you EVER been told by a doctor or other health professional that you have some form of arthritis, rheumatoid arthritis, gout, lupus, or fibromyalgia?”
For assessing the burden of arthritis using health care system data (e.g. hospital discharge data, ambulatory care, death.) a “case” of arthritis is defined by the National Arthritis Data Workgroup definition using arthritis related ICD–9–CM codes [PDF–52K] and is labeled “arthritis and other rheumatic conditions”. The CDC discourages states from using ICD-based assessments unless there is a direct link to program activity that is consistent with the state arthritis plan.
Be aware that other studies (e.g., clinical trials) including some statistics and studies cited elsewhere on this Website, have different data sources and use different arthritis case definitions.
An explanation of the change in the surveillance definition of arthritis that occurred in 2002 is available.