Baseline characteristics of the study population by treatment group
| Adalimumab (n=20) | Placebo (n=20) | |
|---|---|---|
| Age, mean (SD) years | 41.5 (12.8) | 44.4 (11.1) |
| Disease duration, mean (SD) years | 7.9 (9.3) | 6.7 (6.2) |
| Number of men/women | 9/11 | 12/8 |
| BMI, mean (SD) kg/m2 | 24.7 (4.2) | 26.8 (5.7) |
| HLA-B27 positive, n (%) | 11 (55) | 5 (25) |
| Subtype USpA, n (%) | 15 (75) | 17 (85) |
| Subtype ReA, n (%) | 4 (20) | 0 (0) |
| Subtype IBD-SpA, n (%) | 1 (5) | 3 (15) |
| Inflammatory back pain (history/presence), n (%) | 16 (80) | 15 (75) |
| Enthesitis (history/presence), n (%) | 15 (75) | 15 (75) |
| Dactylitis (history/presence), n (%) | 4 (20) | 1 (5) |
| Patient's global assessment, 0–100 mm VAS | 65.8 (18.1) | 68.4 (17.4) |
| Physician's global assessment, 0–100 mm VAS | 47.8 (11.8) | 57.0 (12.6)* |
| Swollen joint count, 0–66 joints | 4.3 (4.2) | 2.5 (1.9) |
| Tender joint count, 0–68 joints | 9.4 (8.2) | 10.6 (5.9) |
| BASDAI | 5.5 (2.3) | 6.0 (1.4) |
| ASDAS | 2.9 (1.0) | 3.2 (0.9) |
| CRP, mg/l | 7.8 (13.3) | 13.5 (26.4) |
| ESR, mm/h | 11.6 (13.5) | 15.7 (23.1) |
| Concomitant NSAIDs, n (%) | 13 (65) | 14 (70) |
| Concomitant corticosteroids, n (%) | 0 (0) | 2 (10) |
| Concomitant MTX, n (%) | 5 (25) | 6 (30) |
| Concomitant SSZ, n (%) | 7 (35) | 4 (20) |
| Previous anti-TNF-treatment, n (%) | 1 (5) | 2 (10) |
Significance of the comparisons is determined by an independent sample t test for continuous variables and χ2 test for categorical variables.
*p Value <0.05 compared with the adalimumab group.
ASDAS, Ankylosing Spondylitis Disease Activity Score; BASDAI, Bath Ankylosing Spondylitis Disease Activity Index; BMI, body mass index; CRP, C reactive protein; ESR, erythrocyte sedimentation rate; HLA-B27, human leukocyte antigen B27; IBD-SpA, inflammatory bowel disease related spondyloarthritis; MTX, methotrexate; NSAIDs, non-steroidal anti-inflammatory drugs; ReA, reactive arthritis; SSZ, sulphasalazine; TNF, tumour necrosis factor; USpA, undifferentiated spondyloarthritis; VAS, visual analogue scale.