Univariable and multivariable analysis of the development of new (bridging) syndesmophytes at 4 years
| Univariable analysis | Multivariable analysis Model 1 | Multivariable analysis Model 2 | |||||||
|---|---|---|---|---|---|---|---|---|---|
| Variables | OR | 95% CI | p Value | OR | 95% CI | p Value | OR | 95% CI | p Value |
| Presence of baseline syndesmophytes | 14.08 | 5.58 to 35.56 | <0.01 | 18.72 | 6.44 to 54.42 | <0.01 | |||
| Age (years) | 1.05 | 1.02 to 1.09 | <0.01 | 1.07 | 1.03 to 1.11 | <0.01 | |||
| Male gender | 3.04 | 1.35 to 6.83 | <0.01 | 3.98 | 1.47 to 10.77 | <0.01 | |||
| BASDAI | 1.01 | 0.86 to 1.20 | 0.88 | ||||||
| BASFI | 1.18 | 1.01 to 1.36 | 0.03 | ||||||
| HLA-B27 positivity | 1.34 | 0.54 to 3.38 | 0.53 | ||||||
| Duration of disease since diagnosis (years) | 1.03 | 0.99 to 1.07 | 0.14 | ||||||
| Duration of symptoms (years) | 1.02 | 0.99 to 1.05 | 0.16 | ||||||
| Presence of hip involvement | 1.61 | 0.70 to 3.66 | 0.26 | ||||||
| ASDAS | 1.40 | 0.98 to 2.00 | 0.06 | ||||||
| CRP | 1.01 | 0.99 to 1.04 | 0.24 | ||||||
|  Elevated CRP | 1.76 | 0.85 to 3.65 | 0.13 | ||||||
| ESR | 1.03 | 1.00 to 1.07 | 0.07 | ||||||
Model 1: All variables with a p-value below 0.10 from the univariable analysis were entered in this model (backward logistic regression model).
Model 2: All variables with a p-value below 0.10 variables from the univariable analysis except for the presence of syndesmophytes at baseline were entered in this model (backward logistic regression model).
ASDAS, Ankylosing Spondylitis Disease Activity Score; BASDAI, Bath Ankylosing Spondylitis Disease Activity Index; BASFI, Bath Ankylosing Spondylitis Functional Index; CRP, C reactive protein; ESR, erythrocyte sedimentation rate; HLA-B27, human leucocyte antigen B27.