Table 4.
Bivariate analysis between the grade of sacroiliac joint damage and clinical features#
| Characteristics | Based on the left sacroiliac joint damage | Based on the right sacroiliac joint damage | ||||
|---|---|---|---|---|---|---|
| Unadjusted OR | 95% CI | p value | Unadjusted OR | 95% CI | p value | |
| Age, per year | 1.016 | 0.985–1.047 | 0.324 | 1.025 | 0.994–1.057 | 0.121 |
| Male, vs female | 1.303 | 0.692–2.454 | 0.412 | 1.281 | 0.680–-2.412 | 0.444 |
| AxSpA duration, per year | 1.189 | 1.103–1.283 | <0.001 | 1.195 | 1.108–1.289 | <0.001 |
| HLA-B27 positive, vs negative | 1.248 | 0.546–2.850 | 0.599 | 1.197 | 0.524–2.732 | 0.670 |
| ESR, per mm/h | 1.024 | 1.011–1.037 | <0.001 | 1.023 | 1.010–1.036 | <0.001 |
| CRP, per mg/l | 1.045 | 1.027–1.063 | <0.001 | 1.041 | 1.024–1.059 | <0.001 |
| Total back pain, per score | 1.298 | 1.169–1.440 | <0.001 | 1.263 | 1.139–1.399 | <0.001 |
| PGA of disease activity, per score | 1.214 | 1.104–1.335 | <0.001 | 1.221 | 1.110–1.343 | <0.001 |
| Pain and swelling of peripheral arthritis, per score | 1.849 | 1.051–3.254 | 0.033 | 1.950 | 1.105–3.441 | 0.021 |
| Duration of morning stiffness, per score | 1.242 | 1.122–1.376 | <0.001 | 1.234 | 1.115–1.367 | <0.001 |
| ASDAS, per score | 1.716 | 1.397–2.107 | <0.001 | 1.671 | 1.362–2.048 | <0.001 |
| BASFI, per score | 3.188 | 2.330–4.364 | <0.001 | 2.811 | 2.081–3.797 | <0.001 |
| Ever use of NSAIDs, vs never | 1.893 | 0.740–4.842 | 0.183 | 1.372 | 0.543–3.471 | 0.504 |
| Use of DMARDs ≥3 months, vs <3 months | 1.922 | 0.751–4.922 | 0.173 | 1.967 | 0.769–5.034 | 0.158 |
| Ever use of biologic DMARDs, vs never | ||||||
| ≥ 12 months | 0.143 | 0.057–0.357 | <0.001 | 0.182 | 0.074–0.444 | <0.001 |
| ≤ 12 months | 0.274 | 0.127–0.592 | 0.001 | 0.244 | 0.113–0.531 | <0.001 |
| ≤ 6 months | 0.795 | 0.404–1.567 | 0.508 | 0.757 | 0.383–1.493 | 0.421 |
| Never | NA | NA | NA | NA | NA | NA |
| Serum uric acid, per μmol/L | 1.001 | 0.999–1.004 | 0.358 | 1.001 | 0.999–1.004 | 0.276 |
| MSU crystallization positive, vs negative | ||||||
| Left sacroiliac joint | 3.368 | 1.841–6.160 | <0.001 | NA | NA | NA |
| Right sacroiliac joint | NA | NA | NA | 3.225 | 1.749–5.946 | <0.001 |
| Hip joint | 0.715 | 0.415–1.232 | 0.227 | 0.674 | 0.390–1.163 | 0.156 |
| Pubic symphysis | 0.971 | 0.554–1.703 | 0.919 | 0.928 | 0.529–1.628 | 0.795 |
| Volume of MSU crystallization, per cm3 | ||||||
| Left sacroiliac joint | 1.990 | 1.308–3.028 | 0.001 | NA | NA | NA |
| Right sacroiliac joint | NA | NA | NA | 1.470 | 1.125–1.922 | 0.005 |
| Total volume at pelvis | 1.015 | 0.983–1.047 | 0.370 | 1.015 | 0.983–1.047 | 0.367 |
AxSpA axial spondyloarthritis, ESR erythrocyte sedimentation rate, CRP C-reactive protein, PGA patient’s global assessment, ASDAS Ankylosing Spondylitis Disease Activity Score, BASFI Bath Ankylosing Spondylitis Functional Index, NSAIDs non-steroidal anti-inflammatory drugs, DMARDs disease-modifying anti-rheumatic drugs, MSU monosodium urate, OR odds ratios, 95% CI 95% confidence interval, NA not available
#Including clinical variables and the DECT scans results