Calculators · Rheumatology · Score

DAS28-CRP (Disease Activity Score, 28 joints, CRP)

Also called DAS28 CRP, DAS28-CRP4

Rheumatoid arthritis disease activity from 28-joint counts, CRP and patient global health.

mm (0–100)

Leave blank to use the validated 3-variable formula.

Fill 3 more fields to see the result.

Formula and scoring

DAS28-CRP(4) = 0.56·√TJC28 + 0.28·√SJC28 + 0.36·ln(CRP mg/L + 1) + 0.014·GH + 0.96. DAS28-CRP(3) = [0.56·√TJC28 + 0.28·√SJC28 + 0.36·ln(CRP + 1)] × 1.10 + 1.15.

Exam and ward pearls

  • CRP must be in mg/L — entering mg/dL without conversion lowers the score.
  • DAS28-CRP gives systematically lower values than DAS28-ESR, so more patients are labelled "remission" at <2.6.

When not to rely on it

  • ESR-derived cut-offs were carried over to the CRP version; interpret borderline values with clinical judgement.

Source

  1. Radboud university medical center. DAS28: how to calculate the DAS28 and alternative validated formulae (das-score.nl). Link
  2. Prevoo ML, van 't Hof MA, Kuper HH, van Leeuwen MA, van de Putte LB, van Riel PL. Modified disease activity scores that include twenty-eight-joint counts. Development and validation in a prospective longitudinal study of patients with rheumatoid arthritis. Arthritis Rheum. 1995;38(1):44-8. doi:10.1002/art.1780380107 · PMID 7818570
  3. England BR, Tiong BK, Bergman MJ, et al. 2019 Update of the American College of Rheumatology recommended rheumatoid arthritis disease activity measures. Arthritis Care Res (Hoboken). 2019;71(12):1540-55. doi:10.1002/acr.24042 · PMID 31709779

Formula and cut-offs checked against these sources on 8 Nov 2026. Educational tool for clinicians; it does not replace clinical judgement.

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