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DAS28-CRP (Disease Activity Score, 28 joints, CRP) for Rheumatoid Arthritis

DAS28-CRP combines 28-joint tender and swollen counts, CRP (mg/L) and the patient global health rating (0–100 mm). The DAS28 thresholds (<2.6 remission, ≤3.2 low, ≤5.1 moderate, >5.1 high) are conventionally applied, although DAS28-CRP runs lower than DAS28-ESR.

  • Tender joint count (28 joints) (joints)
  • Swollen joint count (28 joints) (joints)
  • C-reactive protein (mg/L or mg/dL)
  • Patient global health (VAS 0–100 mm)
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Interpretation

ResultMeaning
< 2.6Remission
2.6–3.2Low
> 3.2–5.1Moderate
> 5.1High

Formula

DAS28-CRP = 0.56 × √TJC28 + 0.28 × √SJC28 + 0.36 × ln(CRP mg/L + 1) + 0.014 × patient global health (0–100 mm) + 0.96

Clinical pearls

  • CRP must be in mg/L (1 mg/dL = 10 mg/L).
  • DAS28-CRP gives systematically lower values than DAS28-ESR, so more patients are classified as remission or low activity with the same thresholds.
  • Use the same DAS28 version for a given patient over time.

Examples

das28 crp tjc 4 sjc 4 crp 10 global 50DAS28-CRP: 12 tender, 10 swollen, CRP 40 mg/L, patient global health 80

FAQ

What units does CRP use in DAS28-CRP?

mg/L. If your lab reports mg/dL, multiply by 10 before entering.

Are the DAS28-CRP cut-offs the same as DAS28-ESR?

The same cut-offs (2.6, 3.2, 5.1) are conventionally used, but DAS28-CRP runs lower, so it may overestimate remission compared with DAS28-ESR.

Evidence

  1. Wells G et al. Validation of the 28-joint Disease Activity Score (DAS28) and EULAR response criteria based on C-reactive protein against disease progression in RA, and comparison with the DAS28 based on ESR. Ann Rheum Dis 2009;68:954–60.
  2. Prevoo ML et al. Modified disease activity scores that include twenty-eight-joint counts. Arthritis Rheum 1995;38:44–8.

General & Anthropometrics · Reviewed 2026-10-14 · Methodology