Table 1.
Characteristics of the ankylosing spondylitis study population
| Total group | Validity study | Reliability study | |
|---|---|---|---|
| Number of patients | 115 | 63 | 52 |
| Age (years) | 44.6 ± 12.1 | 43.2 ± 12.3 | 46.3 ± 11.8 |
| Gender (male) | 71 (62) | 40 (64) | 31 (60) |
| Body mass index | 26.4 ± 4.4 | 26.2 ± 4.8 | 26.6 ± 3.9 |
| Duration of symptoms (years) | 16 (0 to 54) | 18 (2 to 54) | 16 (0 to 53) |
| Time since diagnosis | 10 (0 to 42) | 11 (1 to 42) | 9 (0 to 37) |
| HLA-B27+ | 82 (76) | 49 (82) | 33 (69) |
| Anti-TNF use | 78 (70) | 39 (62) | 39 (81)* |
| NSAID use | 44 (40) | 24 (39) | 20 (42) |
| DMARD use | 17 (15) | 13 (21) | 4 (8) |
| BASDAI (range 0 to 10) | 3.7 (0.0 to 9.0) | 3.8 (0.4 to 8.6) | 3.5 (0.0 to 9.0) |
| ESR (mm/hour) | 11 (2 to 60) | 13 (2 to 60) | 10 (2 to 39) |
| CRP (mg/l) | 3 (2 to 46) | 3 (2 to 44) | 4 (2 to 46) |
| ASDASCRP | 2.3 (0.7 to 4.4) | 2.3 (0.9 to 4.2) | 2.3 (0.7 to 4.4) |
| BASFI (range 0 to 10) | 3.8 ± 2.4 | 3.6 ± 2.4 | 4.2 ± 2.4 |
| Occiput-to-wall distance (cm) | 0.0 (0.0 to 29.0) | 0.0 (0.0 to 29.0) | 0.0 (0.0 to 20.0) |
| Chest expansion (cm) | 5.0 (1.0 to 14.0) | 6.0 (1.0 to 10.5) | 4.0 (1.0 to 14.0)** |
| Modified Schober test (cm) | 4.0 (0.4 to 7.0) | 4.0 (0.4 to 6.2) | 3.9 (0.0 to 7.0) |
| Lateral spinal flexion (cm) | 10.0 (0.0 to 27.0) | 10.0 (0.0 to 25.0) | 10.0 (1.8 to 27.0) |
| Cervical rotation (degrees) | 63 (5 to 98) | 70 (7 to 95) | 58 (5 to 98) |
| ASQoL (range 0 to 18) | 6 (0 to 18) | 6 (0 to 17) | 6 (0 to 18) |
Data presented as mean ± standard deviation, n (%) or median (range). ASDAS, Ankylosing Spondylitis Disease Activity Score; ASQoL, Ankylosing Spondylitis Quality of Life; BASDAI, Bath Ankylosing Spondylitis Disease Activity Index; BASFI, Bath Ankylosing Spondylitis Functional Index; CRP, C-reactive protein; DMARD, disease-modifying antirheumatic drug; ESR, erythrocyte sedimentation rate; HLA-B27+, human leukocyte antigen B27-positive; NSAID, nonsteroidal anti-inflammatory drug; TNF, tumor necrosis factor. *Statistically significant difference compared to the validity study (P < 0.05). **Statistically significant difference compared to the validity study (P < 0.01).