BASDAI — Bath Ankylosing Spondylitis Disease Activity Index
6-question patient-reported outcome measuring disease activity in axial spondyloarthritis (ankylosing spondylitis). Score ≥ 4 indicates active disease — biologic eligibility threshold.
Score interpretation
BASDAI < 4: Low or inactive axial SpA. Treatment response adequate.
→ Continue current therapy. NSAIDs for symptom control (naproxen 500mg BD or diclofenac 75mg BD). Exercise physiotherapy. Annual DEXA if prolonged corticosteroid use. Review 6-monthly.
BASDAI ≥ 4: Active axial spondyloarthritis. Meets threshold for biologic therapy consideration.
→ Confirm active disease on ≥ 2 assessments 4+ weeks apart. Ensure adequate NSAID trial (≥ 2 NSAIDs, 4 weeks each). NICE TA383: anti-TNF biologic (adalimumab, etanercept, golimumab, certolizumab) if BASDAI ≥ 4 + elevated CRP or MRI sacroiliitis. IL-17 inhibitor (secukinumab/ixekizumab) if anti-TNF fails. Physiotherapy mandatory. Smoking cessation (increases axial bone fusion).
Interpretation bands for the BASDAI. Apply clinical judgement and local guidance.
References
- Garrett S et al. A new approach to defining disease status in ankylosing spondylitis: the Bath Ankylosing Spondylitis Disease Activity Index (BASDAI). J Rheumatol. 1994.
- NICE TA383. Adalimumab, etanercept, secukinumab and certolizumab pegol for treating active ankylosing spondylitis. 2016.
Related
Curated clinical cross-links plus same-class fallbacks.
- Natalizumab · Disease-Modifying Therapy — MS (Anti-VLA-4 Monoclonal Antibody)
- Benralizumab · Anti-IL-5 receptor alpha monoclonal antibody (anti-eosinophilic biologic)
- Dupilumab (Moderate-Severe Asthma) · Anti-IL-4/IL-13 receptor alpha monoclonal antibody (type 2 inflammation biologic)
- Tezepelumab · Anti-TSLP (thymic stromal lymphopoietin) monoclonal antibody — broad-phenotype biologic
- Rituximab (Rheumatology) · Biologic DMARD — Anti-CD20
- Guselkumab · Biologic DMARD — IL-23 Inhibitor (Anti-p19)
- Cutaneous Lupus Erythematosus · BAD; EULAR
- Osteoporosis / Fragility Fracture · NOGG 2021; NICE NG147; NG224
- Arteritic AION (Giant Cell Arteritis) · RCOphth; BSR
- Osteoarthritis Hip / Knee Management · NICE NG226 (2022)
- Lupus Nephritis · EULAR/ERA-EDTA 2019; KDIGO 2024
- Rheumatoid Arthritis Management · NICE CG79 2018 / EULAR 2022
Decision support only — verify against a current formulary, NICE, or your local guideline before clinical use.