ASAS axial spondyloarthritis criteria
For patients with back pain for 3 months or more and onset before age 45 — imaging arm or clinical (HLA-B27) arm.
Entry criteria
Imaging and HLA-B27
SpA features
Result
- Imaging arm: sacroiliitis on imaging + ≥1 SpA feature (HLA-B27 counts as a feature here).
- Clinical arm: HLA-B27 + ≥2 other SpA features.
Rudwaleit M, van der Heijde D, Landewé R, et al. The development of Assessment of SpondyloArthritis international Society classification criteria for axial spondyloarthritis (part II). Ann Rheum Dis 2009;68:777–83. Inflammatory back pain per ASAS expert definition; "good response to NSAIDs" = marked improvement within 24–48 h or relapse on withdrawal.
For healthcare professionals. This calculator supports, and does not replace, clinical judgement. Classification criteria are designed for research cohorts and are not diagnostic criteria. Check results against the source publication before acting on them.
Referring a patient?
Walk-in rheumatology OPD at AIMS Mohali — no appointment needed. A short referral note with recent results helps.
Clinic timings & location