Table 4.
Univariate and multivariate linear regressions using SPARCC SI joints MRI score, spinal ADC max, and spinal ADC mean as dependent variables.
| Univariate linear regressions | Multivariate linear regressions | |||||
|---|---|---|---|---|---|---|
| Standard coefficient (B) | Regression coefficient (95% CI) | P value | Standard coefficient (B) | Regression coefficient (95% CI) | P value | |
| SPARCC SI joints MRI score | (n = 366) | |||||
| Axial SpA with late onset (n = 410) | –0.13 | –2.07 (–3.68; –0.46) | 0.01 | 0.10 | 1.63 (–0.17; 3.43) | 0.08 |
| Age (n = 410) | –0.36 | –0.16 (–0.20; –0.12) | <0.001 | –0.41 | –0.18 (–0.23; –0.14) | <0.001 |
| Male gender (n = 410) | 0.06 | 0.73 (–0.46; 1.92) | 0.23 | |||
| Chinese ethnicity (n = 410) | 0.01 | 0.25 (–4.63; 5.13) | 0.92 | |||
| Smoking status (n = 408) | 0.002 | 0.02 (–1.32; 1.36) | 0.98 | |||
| Regular alcohol use (n = 402) | 0.03 | 0.63 (–1.25; 2.51) | 0.51 | |||
| Family history of SpA (n = 395) | –0.08 | –1.14 (–2.56; 0.28) | 0.12 | |||
| HLA–B27 positivity (n = 392) | –0.03 | –0.50 (–2.05; 1.04) | 0.52 | |||
| Radiological AS (n = 396) | –0.01 | –0.15 (–1.36; 1.07) | 0.81 | |||
| Spinal ADC max | (n = 91) | |||||
| Axial SpA with late onset (n = 91) | 0.36 | 326.96 (134.51; 519.42) | 0.001 | 0.27 | 262.94 (34.02; 491.87) | 0.03 |
| Age (n = 91) | 0.27 | 7.31 (1.79; 12.83) | 0.01 | 0.12 | 3.32 (–3.11; 9.74) | 0.31 |
| Male gender (n = 91) | 0.01 | 3.65 (–161.52; 168.81) | 0.97 | |||
| Chinese ethnicity (n = 91) | –0.03 | –71.38 (–602.11; 459.35) | 0.79 | |||
| Smoking status (n = 91) | 0.004 | 3.23 (–159.33; 165.80) | 0.97 | |||
| Regular alcohol use (n = 90) | –0.09 | -109.77 (-358.03; 138.48) | 0.38 | |||
| Family history of SpA (n = 88) | 0.17 | 164.00 (–33.62; 361.62) | 0.10 | |||
| HLA–B27 positivity (n = 87) | –0.002 | –1.77 (–238.91; 235.37) | 0.99 | |||
| Radiological AS (n = 89) | 0.07 | 57.49 (–124.95; 239.93) | 0.53 | |||
| Spinal ADC mean | (n = 91) | |||||
| Axial SpA with late onset (n = 91) | 0.31 | 160.34 (55.80; 264.89) | 0.003 | 0.30 | 156.26 (52.54; 259.99) | 0.004 |
| Age (n = 91) | 0.14 | 2.06 (–0.99; 5.11) | 0.18 | |||
| Male gender (n = 91) | –0.18 | –74.95 (–162.34; 12.43) | 0.09 | -0.16 | –68.90 (–152.77; 14.97) | 0.11 |
| Chinese ethnicity (n = 91) | 0.002 | 2.60 (–282.80; 287.99) | 0.99 | |||
| Smoking status (n = 91) | –0.01 | –3.22 (–90.60; 84.61) | 0.94 | |||
| Regular alcohol use (n = 90) | –0.07 | –45.46 (–179.56; 88.63) | 0.50 | |||
| Family history of SpA (n = 88) | –0.01 | –3.90 (–112.25; 104.44) | 0.94 | |||
| HLA–B27 positivity (n = 87) | –0.15 | –90.62 (–219.04; 37.81) | 0.16 | |||
| Radiological AS (n = 89) | 0.13 | 60.32 (–37.37; 158.01) | 0.22 | |||
ADC = apparent diffusion coefficient; AS = ankylosing spondylitis; CI = confidence interval; HLA = human leukocyte antigen; MRI = magnetic resonance imaging; n = number; SI = sacroiliac; SpA = spondyloarthritis; SPARCC = Spondyloarthritis Research Consortium of Canada.