Diagnosing: Recognizing and proactively identifying patients with nr-axSpA
nr-axSpA criteria in patients with back pain for ≥3 months and age of onset <45 years53,54*
Imaging criteria
of sacroiliitis associated with SpA
Clinical criteria
ASAS classification criteria were developed to identify patients with axSpA (nr-axSpA and AS).53*
Probability of diagnosis53,55,56
The clinical diagnosis of axSpA (nr-axSpA and AS) relies upon a combination of SpA features and imaging.55
The percentages below indicate the percentage of patients who are eventually diagnosed with nr-axSpA.

Among patients with chronic back pain in GP/PCP office:
- The first step to evaluating a patient with chronic back pain for axSpA is to determine whether the back pain is inflammatory or mechanical in nature57

Presence of IBP†:
- IBP is characterized by age at onset <40, insidious onset, improvement with exercise, no improvement with rest, and pain at night with improvement upon getting up53,55

Presence of one or two additional SpA features†:
- Evaluate the patient for the presence of SpA features, including enthesitis, dactylitis, uveitis, a positive family history of SpA, CD, alternating buttock pain, psoriasis, asymmetrical arthritis, a positive response to NSAIDs, and an elevated ESR or CRP to evaluate inflammation53
- Positive HLA-B27 test result is associated with an increased likelihood that the patient has axSpA53
- At least three axSpA features will increase the probability to 80% to 95%55

- HLA-B27(+) (80%-90%55†)
- Imaging: X-ray SIJ (+) = AS57
- X-ray SIJ (–), MRI SIJ (+) = nr-axSpA57
Prevalence of extraspinal manifestations in nr-axSpA patients‡
‡Prevalence includes all axial and peripheral SpA disease states.
AS: ankylosing spondylitis; ASAS: Assessment of SpondyloArthritis international Society; CD: Crohn’s disease; CRP: C-reactive protein; ESR: erythrocyte sedimentation rate; GP: general practitioner; HLA-B27+: human leukocyte antigen-B27 positive; IBD: inflammatory bowel disease; IBP: inflammatory back pain; MRI: magnetic resonance imaging; nr-axSpA: non-radiographic axial spondyloarthritis; NSAID: nonsteroidal anti-inflammatory drug; PCP: primary care physician; SIJ: sacroiliac joint; SpA: spondyloarthritis.