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

RA disease activity using 28-joint counts, patient global health, and CRP.

Disease Activity Score-28 for Rheumatoid Arthritis with CRP (DAS28-CRP)
Tender joint count (28-joint)
joints
Swollen joint count (28-joint)
joints
CRP
mg/L
Patient global health assessment
0-100 mm visual analogue scale (0 = very well, 100 = very poor).
mm (0-100)
Complete the fields above to see the result.

When to use

  • Standardized quantification of rheumatoid arthritis disease activity when CRP, rather than ESR, is the available acute-phase marker.
  • Treat-to-target monitoring and EULAR response assessment in RA clinical trials and practice.

Formula

DAS28-CRP = 0.56 x sqrt(TJC28) + 0.28 x sqrt(SJC28) + 0.36 x ln(CRP[mg/L]+1) + 0.014 x patient global health (0-100 mm VAS) + 0.96. Remission <2.6, low activity 2.6-<3.2, moderate activity 3.2-5.1, high activity >5.1.

Pearls and pitfalls

  • Runs numerically slightly lower than DAS28-ESR at comparable disease activity, but the same conventional cut-points are applied in practice.
  • Requires a 28-joint tender and swollen joint count (not the full 68/66-joint exam).

References

  1. Fransen J, van Riel PL. The Disease Activity Score and the EULAR response criteria. Clin Exp Rheumatol. 2005;23(5 Suppl 39):S93-9.
  2. Prevoo ML, van 't Hof MA, Kuper HH, et al. Modified disease activity scores that include twenty-eight-joint counts. Arthritis Rheum. 1995;38(1):44-8.