Baseline demographic and clinical characteristics of included patients with axial spondyloarthritis
| Parameter | All patients (n=208) | r-axSpA (n=115) | nr-axSpA (n=93) |
| Age, years | 37.3±10.6 | 36.1±11.0 | 38.6±10.0 |
| Duration of symptoms, years | 4.2±2.7 | 5.0±2.8 | 3.1±2.2 |
| Male sex, n (%) | 106 (51) | 75 (65.2) | 31 (33.3) |
| HLA-B27 carrier, n (%) | 165 (79.3) | 97 (84.3) | 68 (73.9) |
| Peripheral arthritis, n (%) | 31 (14.9) | 15 (13.0) | 16 (17.2) |
| Enthesitis*, n (%) | 45 (21.6) | 23 (20.5) | 22 (23.9) |
| Uveitis ever, n (%) | 45 (21.6) | 27 (23.5) | 18 (19.4) |
| Psoriasis ever, n (%) | 28 (13.5) | 18 (15.7) | 10 (10.8) |
| IBD ever, n (%) | 4 (1.9) | 3 (2.6) | 1 (1.1) |
| Family history of SpA, n (%) | 35 (16.8) | 19 (16.5) | 16 (17.2) |
| BASDAI, points NRS (0–10) | 3.9±2.1 | 3.8±2.2 | 4.1±2.0 |
| BASFI, points NRS (0–10) | 2.9±2.3 | 3.0±2.4 | 2.8±2.2 |
| BASMI, points (0–10) | 1.8±1.6 | 2.0±1.7 | 1.5±1.5 |
| CRPbaseline, mg/L | 7.48±8.6 | 9.64±9.9 | 4.82±5.6 |
| mSASSS, points | 4.3±8.4 | 5.9±10.3 | 2.3±4.3 |
| Smoking, n (%) | 63 (30.3) | 39 (33.9) | 24 (25.8) |
| Treatment with NSAIDs, n (%) | 139 (66.8) | 76 (66.1) | 63 (67.7) |
| Treatment with DMARDs, n (%) | 53 (25.5) | 31 (26.9) | 22 (23.6) |
| Treatment with systemic steroids, n (%) | 12 (5.8) | 6 (5.2) | 6 (6.4) |
| Treatment with a TNF-α inhibitor, n (%) | 5 (2.4) | 4 (3.7) | 1 (1.1) |
*The Berlin score assesses 12 enthesitis sites of lower limbs plus optional sites elsewhere. Continuous variables are presented as mean±SD.
BASDAI, bath ankylosing spondylitis disease activity index; BASFI, bath ankylosing spondylitis functional index; BASMI, bath ankylosing spondylitis metrology index; CRPbaseline, C-reactive protein level at baseline; DMARD, disease-modifying anti-rheumatic drug; IBD, inflammatory bowel disease; mSASSS, modified Stoke Ankylosing Spondylitis Spinal Score; nr-axSpA, non-radiographic axial spondyloarthritis at baseline; NSAID, non-steroidal anti-inflammatory drug; r-axSpA, radiographic axial spondyloarthritis at baseline; TNF-α, tumour necrosis factor alpha.