Table 1.
Baseline demographic characteristics and comparison between nonradiographic axial SpA (nr-axSpA) and AS.
| Characteristics | Total axSpA (N = 357) |
Nr-axSpA (N = 96) |
AS (N = 261) |
p † |
|---|---|---|---|---|
| Age (years) | 38.7 ± 11.2 | 34.8 ± 10.7 | 40.1 ± 11.1 | <0.001 |
| Diagnosed age (years) | 31.0 ± 11.5 | 29.3 ± 10.9 | 31.6 ± 11.6 | 0.083 |
| Disease duration (years) | 7.6 ± 6.6 | 5.3 ± 3.8 | 8.4 ± 7.2 | <0.001 |
| Male gender (N, %) | 273 (76.5%) | 66 (68.8%) | 207 (79.3%) | 0.052 |
| BMI (kg/m2) | 24.0 ± 3.3 | 23.3 ± 3.2 | 24.3 ± 3.2 | 0.008 |
| Education | 0.864 | |||
| Below high school | 102 (29.8%) | 26 (28.6%) | 76 (30.3%) | |
| College or postgraduate | 240 (70.2%) | 65 (71.4%) | 175 (69.7%) | |
| Salary | 0.026 | |||
| <50,000 US dollar/year | 244 (71.8%) | 74 (81.3%) | 170 (68.3%) | |
| ≥50,000 US dollar/year | 96 (28.2%) | 17 (18.7%) | 79 (31.7%) | |
| Marriage | 0.001 | |||
| Single/divorced/bereaved | 151 (42.4%) | 55 (57.3%) | 96 (36.9%) | |
| Married | 205 (57.6%) | 41 (42.7%) | 164 (63.1%) | |
| Current smoker | 99 (28.0%) | 17 (17.9%) | 82 (31.8%) | 0.015 |
| Current alcohol drinker | 244 (69.1%) | 68 (70.8%) | 176 (68.5%) | 0.767 |
| Uveitis | 161 (45.5%) | 33 (34.4%) | 128 (49.6%) | 0.015 |
| IBD | 6 (1.7%) | 1 (1.0%) | 5 (1.9%) | 0.903 |
| Dactylitis | 28 (7.9%) | 10 (10.4%) | 18 (7.0%) | 0.398 |
| Psoriasis | 17 (4.8%) | 3 (3.1%) | 14 (5.4%) | 0.535 |
AS—ankylosing spondylitis; axSpA—axial spondyloarthritis; BMI—body mass index; IBD—inflammatory bowel disease; nr-axSpA—nonradiographic axial spondyloarthritis; Data are shown as mean ± standard deviation (SD). † Comparison between AS and nr-axSpA.