Table 5. Univariable and multivariable logistic regression analyses for determinants of ASAS HI > 5 in patients with ankylosing spondylitis.
| Univariable | Multivariable* | ||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| Model A | Model B | Model C | Model D | ||||||||
| Variable | OR (95% CI) | P | VIF | OR (95% CI) | P | OR (95% CI) | P | OR (95% CI) | P | OR (95% CI) | P |
| Gender, male | 0.36 (0.20–0.64) | <0.001 | 1 | 0.25 (0.11–0.54) | 0.001 | 0.14 (0.06–0.32) | <0.001 | 0.15 (0.07–0.36) | <0.001 | 0.14 (0.06–0.33) | <0.001 |
| Age, year | 1.03 (1.01–1.05) | 0.003 | 2 | 0.98 (0.95–1.01) | 0.263 | 1.00 (0.97–1.03) | 0.967 | 0.99 (0.95–1.03) | 0.453 | 0.99 (0.96–1.02) | 0.520 |
| Disease duration, year | 1.03 (1.01–1.06) | 0.001 | 2 | 1.05 (1.01–1.09) | 0.009 | 1.04 (1.00–1.07) | 0.040 | 1.04 (1.00–1.08) | 0.047 | 1.03 (0.99–1.07) | 0.063 |
| Smoking, n (%) | 1.01 (0.63–1.62) | 0.982 | 1.12 (0.60–2.10) | 0.718 | 1.05 (0.57–1.95) | 0.877 | 1.18 (0.61–2.27) | 0.623 | 1.17 (0.61–2.24) | 0.648 | |
| No. of comorbidities | 1.34 (1.10–1.62) | 0.003 | 1 | 1.28 (0.98–1.67) | 0.071 | 1.27 (0.98–1.65) | 0.077 | 1.30 (0.98–1.72) | 0.066 | 1.30 (0.98–1.72) | 0.065 |
| Extra-spinal manifestation | 1.70 (1.06–2.72) | 0.028 | 1 | 0.94 (0.53–1.69) | 0.845 | 0.96 (0.54–1.70) | 0.895 | 0.96 (0.52–1.76) | 0.891 | 0.99 (0.54–1.81) | 0.973 |
| Family history of AS | 1.33 (0.83–2.14) | 0.230 | 1.22 (0.69–2.18) | 0.491 | 1.23 (0.70–2.70) | 0.476 | 1.29 (0.70–2.36) | 0.410 | 1.29 (0.70–2.36) | 0.411 | |
| ESR, mm/hour | 1.03 (1.01–1.05) | 0.002 | 5 | 1.01 (0.99–1.04) | 0.255 | ||||||
| CRP, mg/dl | 1.32 (0.98–1.77) | 0.065 | 1.06 (0.81–1.39) | 0.664 | |||||||
| ASDAS-ESR | 4.05 (2.73–6.02) | <0.001 | 18 | 4.15 (2.65–6.49) | <0.001 | ||||||
| ASDAS-CRP | 2.72 (1.97–3.75) | <0.001 | 5 | 3.05 (2.11–4.39) | <0.001 | ||||||
| BASDAI | 2.27 (1.83–2.83) | <0.001 | 7 | 2.47 (1.92–3.20) | <0.001 | 2.47 (1.91–3.19) | <0.001 | ||||
| mSASSS | 1.02 (1.01–1.03) | 0.004 | 1 | 1.02 (1.00–1.03) | 0.025 | 1.01 (1.00–1.03) | 0.031 | 1.02 (1.01–1.04) | 0.006 | 1.02 (1.01–1.04) | 0.005 |
| AIC | 325 | 333 | 306 | 307 | |||||||
*Gender, age, disease duration, smoking, number of comorbidities, extra-spinal manifestations, family history of AS, mSASSS, and disease activity (model A, ASDAS-ESR; model B, ASDAS-CRP; model C, BASDAI+ESR; model C, BASDAI+CRP) were included in the multivariable analyses.
Abbreviations: ASAS HI, assessment of spondyloarthritis international society health index; OR, odds ratio; CI, confidence interval; P, p-value; VIF, variance inflation fraction; ESR, erythrocyte sedimentation rate; CRP, C-reactive protein; ASDAS, ankylosing spondylitis disease activity score; BASDAI, Bath ankylosing spondylitis disease activity index; mSASSS, modified Stoke ankylosing spondylitis spinal score; AIC, Akaike information criterion.