| Age (years), mean (range) | Males (%) | HLA-B27 + (%) | BASDAI (mean) | BASFI (mean) | |
| All patients (n = 350) | 40 (16 to 75) | 48.6 | 61.1 | — | — |
| All axial SpA (n = 159) | 37.2 (17 to 71) | 55.3 | 85.5 | 4.1 | 3.2 |
| Pre-radiographic SpA (n = 79) | 33.8 (17 to 61) | 50.6 | 83.5 | 4.1 | 2.8 |
| Radiographic SpA (n = 80) | 40.5 (17 to 71) | 60 | 87.5 | 4.1 | 3.6 |
| Possible SpA (n = 32) | 35 (20 to 61) | 50 | 62.5 | 4.2 | 2.1 |
| Non-SpA (n = 159) | 43.8 (16 to 75) | 41.5 | 36.5 | — | — |
BASFI, Bath Ankylosing Spondylitis Functional Index; BASDAI, Bath Ankylosing Spondylitis Disease Activity Index; HLA, human leucocyte antigen.
Results are shown for different groups as detailed in column 1.