1. What is the DAS28-ESR?

The DAS28-ESR (Disease Activity Score using 28 joints with ESR) is a measure of disease activity in rheumatoid arthritis that combines tender and swollen joint counts, ESR, and patient global assessment.

2. How Does the Calculator Work?

The calculator uses the DAS28-ESR equation:

Where:

• \( TJC28 \) — Tender joint count (0-28 joints)
• \( SJC28 \) — Swollen joint count (0-28 joints)
• \( ESR \) — Erythrocyte sedimentation rate (mm/hr)
• \( VAS \) — Patient global health visual analog scale (0-100mm)

Interpretation:

• DAS28 ≤ 2.6: Remission
• 2.6 < DAS28 ≤ 3.2: Low disease activity
• 3.2 < DAS28 ≤ 5.1: Moderate disease activity
• DAS28 > 5.1: High disease activity

3. Importance of DAS28 Calculation

Details: The DAS28 score helps rheumatologists assess disease activity, guide treatment decisions, and monitor response to therapy in rheumatoid arthritis patients.

4. Using the Calculator

Tips: Enter tender and swollen joint counts (0-28), ESR in mm/hr, and VAS score (0-100mm). All values must be valid (ESR > 0).

5. Frequently Asked Questions (FAQ)

Q1: What joints are included in the 28-joint count?
A: Shoulders, elbows, wrists, MCPs (1-5), PIPs (1-5), and knees (total 28 joints).

Q2: What's the difference between DAS28-ESR and DAS28-CRP?
A: DAS28-CRP uses C-reactive protein instead of ESR, with slightly different coefficients in the formula.

Q3: How often should DAS28 be measured?
A: Typically every 3-6 months in active disease, or more frequently when changing treatment.

Q4: Are there limitations to DAS28?
A: Yes, it doesn't assess foot joints or structural damage, and may underestimate disease in some patients.

Q5: What is considered a clinically significant change in DAS28?
A: A change of >1.2 points is considered large, 0.6-1.2 moderate, and <0.6 small.