How it's calculated
DAS28-ESR = 0.56×√(tender joint count) + 0.28×√(swollen joint count) + 0.70×ln(ESR) + 0.014×patient global health (0-100mm VAS), using standardised 28-joint counts.
Interpretation
| DAS28-ESR | Disease activity |
|---|---|
| < 2.6 | Remission |
| 2.6 - 3.2 | Low disease activity |
| >3.2 - 5.1 | Moderate disease activity |
| > 5.1 | High disease activity |
Clinical use
- Used to monitor rheumatoid arthritis disease activity over time and guide treat-to-target strategies, where treatment is escalated until remission or low disease activity is achieved.
- The 28 joints assessed are standardised (shoulders, elbows, wrists, MCPs, PIPs, and knees bilaterally) — using a different joint count invalidates comparison against published thresholds.
- A CRP-based variant (DAS28-CRP) uses a slightly different formula and tends to give marginally lower values than DAS28-ESR for the same clinical state.
- Response to treatment is often assessed using EULAR response criteria, which consider both the absolute DAS28 achieved and the magnitude of change from baseline.
Frequently asked questions
What is DAS28 used for?
It quantifies rheumatoid arthritis disease activity from joint counts, an inflammatory marker, and patient-reported global health, used to monitor response to treatment and guide treat-to-target strategies.
Which 28 joints are counted?
Bilateral shoulders, elbows, wrists, metacarpophalangeal (MCP) joints, proximal interphalangeal (PIP) joints, and knees — a standardised joint set that must be used consistently for the score to be valid.
What is the difference between DAS28-ESR and DAS28-CRP?
They use different formulas incorporating either ESR or CRP as the inflammatory marker; DAS28-CRP tends to give slightly lower values than DAS28-ESR for an equivalent clinical state.
What DAS28 score indicates remission?
A DAS28-ESR below 2.6 is generally considered to indicate remission, a common treat-to-target goal in rheumatoid arthritis management.
References
- Prevoo ML, et al. Modified disease activity scores that include twenty-eight-joint counts. Arthritis Rheum. 1995;38(1):44-48.
- Fransen J, van Riel PL. The Disease Activity Score and the EULAR response criteria. Clin Exp Rheumatol. 2005;23(5 Suppl 39):S93-99.