| Regression model (1) | Regression model (1) adjusted for baseline x-ray score | Regression model (2) with anti-CCP as a continuous variable | ||||||
| B | OR (95%CI) | B | OR (95%CI) | B | OR (95%CI) | |||
| Anti-CCP+ | 1.38 | 4.00 (1.60–10.00) | 1.15 | 3.13 (1.17–8.38) | ||||
| Female gender | 1.20 | 3.32 (1.34–7.57) | 1.15 | 3.15 (1.06–9.36) | 1.21 | 3.36 (1.20–9.40) | ||
| ESR >20 mm/h | 1.16 | 3.18 (1.19–7.57) | 1.34 | 3.11 (1.25–7.76) | 1.14 | 3.13 (1.31–7.47) | ||
| IgM RF+ | 1.12 | 3.07 (1.18–7.94) | 1.00 | 2.70 (1.01–7.33) | 1.29 | 3.64 (1.44–9.18) | ||
| Baseline progression rate (SHS/year) | 0.22 | 1.25 (1.04–1.48) | ||||||
| Anti-CCP U/ml | 0.01 | 1.008 (1.003–1.012) | ||||||
| Accuracy | 73.6 | 76.5 | 77.6 | |||||
| Sensitivity | 89.2 | 81.1 | 86.5 | |||||
| Specificity | 51.0 | 76.5 | 64.7 | |||||
SHS, van der Heijde modified Sharp score; Baseline progression rate, SHS at baseline divided by disease duration (years) at baseline; Anti-CCP+, a positive test for antibodies to cyclic citrullinated peptide; IgM RF+, a positive immunoglobulin M rheumatoid factor test; ESR, erythrocyte sedimentation rate; IQR, Inter Quartile Range; B, beta; OR, odds ratio.