ASDAS (Ankylosing Spondylitis Disease Activity Score)
Ankylosing Spondylitis Disease Activity Score (ASDAS) from four 0–10 patient items plus CRP (mg/L, preferred) or ESR (mm/h), banded inactive / low / high / very-high.
Open the calculator → Runs in your browser. Data leaves only if you deliberately send a problem report from the interactive tool.
Example
- Back pain
- 4
- Morning stiffness
- 3
- Patient global
- 5
- Peripheral pain/swelling
- 2
- CRP
- 10 mg/L
Result: ASDAS-CRP 2.74 — high disease activity (2.1–3.5).
The tool opens with these values already filled in. Replace them with your own.
What the result means
- Cutoffs
- inactive < 1.3, low 1.3–<2.1, high 2.1–3.5, very high > 3.5; a change ≥ 1.1 is clinically important, ≥ 2.0 a major improvement.
What you enter
- Back pain (0–10)
- Morning stiffness (0–10)
- Patient global (0–10)
- Peripheral pain/swelling (0–10)
- CRP (preferred)
- ESR (if no CRP)
How this is calculated
- Formula
- ASDAS-CRP = 0.12·back pain + 0.06·morning stiffness + 0.11·patient global + 0.07·peripheral pain + 0.58·ln(CRP+1); CRP in mg/L floored to 2. ASDAS-ESR uses 0.08/0.07/0.11/0.09 + 0.29·√ESR.
Lukas C, Landewé R, Sieper J, et al. Development of an ASAS-endorsed disease activity score (ASDAS) in patients with ankylosing spondylitis. Ann Rheum Dis. 2009;68(1):18-24. Read the source ↗
A reference and educational tool. Not medical, legal, or financial advice, and not a substitute for clinician judgment.