Baseline demographic, clinical and radiographic characteristics
| Assessment | N=184 mean (SD) or n (%) |
|---|---|
| Age (years) | 43 (12) |
| Male gender (%) | 129 (70%) |
| HLA-B27 positive (%) | 149 (83%) |
| Symptoms duration (years) | 20 (12) |
| Disease duration (years) | 11 (9) |
| ASDAS-CRP | 2.6 (1.0) |
| BASDAI (0–10) | 3.4 (2.0) |
| CRP (mg/L) | 17.4 (23.3) |
| Elevated CRP (%)* | 85 (48%) |
| ESR (mm/h) | 14.0 (15.0) |
| Patient's global assessment of disease activity (0–10) | 3.7 (2.7) |
| Spinal pain (0–10) | 3.5 (2.3) |
| mSASSS (0–72) | 10.8 (15.2) |
| mSASSS >0 (%) | 140 (81%) |
| NSAIDs (%) | 125 (68%) |
| Tumour necrosis factor α inhibitors (%) | 0 (0%) |
*The cut-off was 10 mg/L for the Dutch patients and 5 mg/L for the Belgian and French patients.
ASDAS-CRP, Ankylosing Spondylitis Disease Activity Score (C-reactive protein); BASDAI, Bath Ankylosing Spondylitis Disease Activity Score; CRP, C-reactive protein; ESR, erythrocyte sedimentation rate; mSASSS, modified Stoke Ankylosing Spondylitis Spine Score; NSAIDs, non-steroidal anti-inflammatory drugs.