DAS28 ESR CRP RA Activity Score Calculator

DAS28 ESR CRP Rheumatoid arthritis activity score Explanation and clinical context DAS28 is a composite score used to quantify disease activity in patients with rheumatoid arthritis using 28 joint counts for tenderness and swelling combined with a patient reported global health measure and one inflammatory biomarker. The score can be calculated using either erythrocyte sedimentation rate or C reactive protein. The formula using erythrocyte sedimentation rate includes a natural logarithm of ESR while the formula using C reactive protein uses a transformation of CRP plus one and includes an additive constant that aligns the CRP based score to the ESR based score.

Lower scores indicate less disease activity and higher scores indicate more active disease. Common interpretation thresholds are remission when the score is less than or equal to 2.6 low disease activity when the score is greater than 2.6 to 3.2 moderate disease activity when the score is greater than 3.2 to 5.1 and high disease activity when the score is greater than 5.1. Reference Classic methodological and validation literature for DAS28 and practical guidance from rheumatology societies and peer reviewed journals describe the derivation and interpretation of these formulas.

For clinical use consult primary rheumatology sources and guideline documents.