the current intensity or severity of signs and symptoms resulting from an ongoing disease process — in rheumatoid arthritis, this typically reflects the degree of inflammation. Rheumatologists assess disease activity using standardized instruments and scoring systems, which set cut-off points to classify levels of activity. Although four categories are commonly recognized — high, moderate, low, and remission — the precise definitions of these states vary depending on the measurement tool used.
Example
A rheumatologist evaluates a patient with rheumatoid arthritis using the DAS28 score, which incorporates tender and swollen joint counts, a blood test (ESR or CRP), and the patient’s own assessment of disease. A DAS28 score above 5.1 indicates high disease activity, while a score below 2.6 indicates remission.