DAS28-ESR: The gold standard for measuring RA disease activity.
Joints
Joints
mm/hr
0-100
Enter Joint Counts
Fill in all 4 values above to calculate your DAS28 score and disease activity level.
Guidelines & Evidence
Verified
Last Review: 2026-07-17
When to Use
When to Use
Rheumatoid arthritis disease activity monitoring in adults
Guiding treat-to-target therapy decisions in RA
Serial tracking of treatment response over time
Clinical trial endpoint for RA therapeutics
Deciding when to escalate or taper DMARD therapy
Patient Population
Adults with confirmed rheumatoid arthritis by ACR/EULAR 2010 criteria. The DAS28 is validated for both early and established RA and is used across all disease durations.
Contraindications
Not validated for other inflammatory arthritides (psoriatic arthritis, ankylosing spondylitis)
May be less reliable in patients with concurrent fibromyalgia due to elevated tender joint counts
ESR may be falsely elevated in elderly, anemia, pregnancy, or infection
How it Works
Formula
DAS28 = 0.56 × sqrt(TJC28) + 0.28 × sqrt(SJC28) + 0.70 × ln(ESR) + 0.014 × GH
TJC28: Tender joint count (0–28)
SJC28: Swollen joint count (0–28)
ESR: Erythrocyte sedimentation rate (mm/hr)
GH: Patient global health VAS (0–100 mm)
DAS28-CRP Alternative
An alternate version using CRP instead of ESR is available. DAS28-CRP tends to produce slightly lower scores than DAS28-ESR and may overestimate the proportion of patients achieving remission. The original remission threshold of 2.6 was derived using ESR. Using the same version consistently in the same patient is more important than which version you choose.
Component Details
01
Tender joint count: Assess 28 joints (shoulders, elbows, wrists, MCPs, PIPs, knees) for tenderness on pressure or passive motion
02
Swollen joint count: Assess the same 28 joints for synovial swelling
03
ESR: Measured by Westergren method in mm/hr, preferably drawn on the same day as the joint assessment
04
Patient global: 0-100 mm VAS asking "Considering all the ways your arthritis affects you, how well are you doing?"
Clinical Pearls
Clinical Application
The DAS28 is the most widely used disease activity measure in RA worldwide and is the standard endpoint in treat-to-target protocols. Its four components capture different dimensions of disease activity: tender joints reflect the patients subjective pain experience, swollen joints provide the most objective measure of synovitis, ESR gives a systemic inflammatory marker, and patient global captures the patients overall perception of their disease. When these components move in the same direction, treatment decisions are straightforward. When they conflict, the discrepancy itself is clinically informative and may signal conditions that masquerade as active RA, such as fibromyalgia, osteoarthritis, or tendinopathy.
Pitfalls to Avoid
A normal ESR does not rule out active RA; CRP may be more sensitive
Patient global assessment can be influenced by non-articular pain conditions and depression
Tender joint counts can be misleadingly high in fibromyalgia while swollen joint counts are more specific
ESR increases with age, anemia, and hypergammaglobulinemia, producing falsely elevated scores in elderly patients
Next Steps
Score Interpretation Guide
| Score Range | Disease Activity | Clinical Action |
|---|---|---|
| < 2.6 | Remission | Maintain current therapy; consider tapering if sustained |
| 2.6 - 3.2 | Low | Continue current therapy; monitor closely |
| 3.2 - 5.1 | Moderate | Consider escalating DMARD therapy; add or switch biologic |
| > 5.1 | High | Escalate therapy urgently; consider combination DMARDs or biologic + MTX |
Treatment Implications
A DAS28 score should trigger a structured clinical response. For patients in moderate or high disease activity despite methotrexate, the EULAR guidelines recommend adding a biologic DMARD or JAK inhibitor within 3 months. A DAS28 that is falling but has not yet reached target should prompt continued escalation rather than watchful waiting, as evidence from TICORA and CAMERA demonstrates that delaying escalation leads to irreversible joint damage.
When to Reassess
Every 1-3 months during active treatment escalation
Every 3-6 months once treatment target (remission or low activity) is achieved
Immediately if there is a flare in symptoms between scheduled visits
Before and after biologic therapy initiation or switching
The Evidence
Key Evidence
TICORA trial: Tight control (DAS28-driven) achieved 65% remission vs 16% in routine care (p < 0.0001) at 18 months
CAMERA trial: Intensive MTX dosing guided by DAS28 improved radiographic outcomes
DAS28 correlates with radiographic progression, functional status, and mortality across multiple cohorts
EULAR recommends DAS28 as a core outcome measure for all RA clinical trials
Primary Reference
Modified disease activity scores that include twenty-eight-joint counts. Development and validation in a prospective longitudinal study of patients with rheumatoid arthritis.
Prevoo ML et al. • Arthritis and Rheumatism. 1995;38(1):44-8
The Disease Activity Score and the EULAR response criteria.
Fransen J et al. • Clinical and Experimental Rheumatology. 2005;23(5 Suppl 39):S93-9
Origins & History
Development
The DAS28 was developed by Prevoo and colleagues in 1995 as a modification of the original Disease Activity Score (DAS), which used the 44-joint count. The 28-joint version was designed to reduce the examination burden while maintaining discriminant validity. The tender joint and swollen joint counts are performed on only 28 joints (excluding the feet and ankles), which were shown to contribute minimal additional information. The DAS28 has been validated in hundreds of clinical trials and observational cohorts and is endorsed by EULAR and ACR as a core outcome measure for rheumatoid arthritis.
Last Comprehensive Review: 2026-07-17