Table 2.
Comparison of laboratory, radiographic, and axSpA related parameters between nr-axSpA and ankylosing spondylitis (AS).
| Variables | Total axSpA (N = 357) |
Nr-axSpA (N = 96) |
AS (N = 261) |
p † |
|---|---|---|---|---|
| CRP elevation (>0.5 mg/dL) | 67 (18.8%) | 8 (8.3%) | 59 (22.7%) | 0.003 |
| HLA-B27 positive | 310 (93.1%) | 82 (87.2%) | 228 (95.4%) | 0.016 |
| High NSAID intake (ASAS NSAID index ≥ 50) | 195 (54.6%) | 43 (44.8%) | 152 (58.2%) | 0.032 |
| Sulfasalazine | 122 (34.3%) | 32 (33.3%) | 90 (34.6%) | 0.920 |
| TNF-α inhibitor | 170 (47.8%) | 41 (42.7%) | 129 (49.6%) | 0.299 |
| Sum of sacroiliitis grade (0–8) | 5.0 ± 2.1 | 2.1 ± 0.9 | 6.0 ± 1.4 | <0.001 |
| mSASSS (0–72) | 12.2 ± 18.7 | 3.0 ± 5.1 | 15.6 ± 20.6 | <0.001 |
| Presence of syndesmophyte | 210 (58.8%) | 36 (37.5%) | 174 (66.7%) | <0.001 |
| BASDAI (0–10) | 3.1 ± 1.9 | 2.7 ± 1.7 | 3.2 ± 2.0 | 0.023 |
| ASDAS-CRP (0–10) | 1.9 ± 0.9 | 1.6 ± 0.7 | 2.0 ± 0.9 | <0.001 |
| ASDAS-ESR (0–10) | 2.0 ± 0.9 | 1.7 ± 0.7 | 2.1 ± 1.0 | <0.001 |
| BASFI (0–10) | 1.0 ± 1.4 | 0.5 ± 0.8 | 1.1 ± 1.5 | <0.001 |
| PGA (0–10) | 3.2 ± 2.2 | 2.6 ± 1.9 | 3.4 ± 2.3 | 0.001 |
| Spinal pain VAS (0–10) | 2.8 ± 2.4 | 2.2 ± 2.0 | 3.1 ± 2.5 | 0.001 |
| Nocturnal spinal pain VAS (0–10) | 2.3 ± 2.3 | 1.7 ± 2.1 | 2.5 ± 2.3 | 0.003 |
| PhyGA (0–10) | 2.4 ± 1.6 | 2.1 ± 1.6 | 2.4 ± 1.6 | 0.131 |
| EQ-5D-TTO (0–1) | 0.79 ± 0.10 | 0.82 ± 0.08 | 0.78 ± 0.10 | 0.001 |
| EQ-VAS (0–100) | 72.0 ± 18.1 | 72.9 ± 18.5 | 71.7 ± 17.9 | 0.577 |
| ASAS health index (0–17) | 3.5 ± 3.4 | 2.7 ± 2.8 | 3.8 ± 3.5 | 0.003 |
| Health index | 0.053 * | |||
| Poor (≥12) | 13 (3.6%) | 1 (1.0%) | 12 (4.6%) | |
| Moderate (5–12) | 73 (20.4%) | 14 (14.6%) | 59 (22.6%) | |
| Good (≤5) | 271 (75.9%) | 81 (84.4%) | 190 (72.8%) | |
| Environmental factor related to ASAS health index (0–9) | 2.1 ± 1.6 | 1.8 ± 1.2 | 2.2 ± 1.7 | 0.009 |
AS—ankylosing spondylitis; ASAS—Assessment of Spondyloarthritis International Society; ASDAS—Ankylosing Spondylitis Disease Activity Score; axSpA—axial spondyloarthritis; BASDAI—Bath Ankylosing Spondylitis Disease Activity Index; BASFI—Bath Ankylosing Spondylitis Functional Index; CRP—C-reactive protein; EQ-5D—EuroQol-5 dimensions; ESR—erythrocyte sedimentation rate; HLA—human leukocyte antigen; modified Stoke Ankylosing Spondylitis Spinal Score; nr-axSpA—nonradiographic axial spondyloarthritis; NSAID—nonsteroidal anti-inflammatory drug; PGA—patient global assessment; PhyGA—physician global assessment; TNF—tumor necrosis factor; TTO—time trade-off; VAS—visual analogue scale; Data are shown as mean ± standard deviation (SD). † Comparison between AS and nr-axSpA. * The Mantel–Haenszel χ2 test was used.