| Anti-CCP levels | Mean (SD) Change SHS | Unadjusted OR (95% CI) for progression compared with anti-CCP-negative patients | Adjusted† OR (95% CI) for progression compared with anti-CCP-negative patients | OR (95% CI) for progression compared with patients with low to moderate anti-CCP levels | OR (95% CI) for progression compared with patients with anti-CCP levels <200 |
| Negative (<25 U/ml) | 13.1* (20.3) | ||||
| Low–moderate (25–200 U/ml) | 31.4* (29.1) | 3.54 (1.49 to 8.39) | 2.58 (0.93 to 7.20) | ||
| High (>200 U/ml) | 46.3* (28.6) | 13.29 (4.03 to 43.81) | 9.86 (2.65 to 36.70) | 4.81 (1.19 to 19.15) | 6.32 (1.84 to 21.6) |
| Accuracy | 64.7 | 78.4 | 79.2 | ||
| Sensitivity | 75.7 | 78.4 | 86.5 | ||
| Specificity | 71.2 | 78.4 | 68.6 |
*Statistical significant (p<0.05) difference between groups.
†Adjusted for IgM RF, ESR, CRP, sex, age.
SHS, van der Heijde modified Sharp score; Baseline progression rate, SHS at baseline divided by disease duration (years) at baseline; Anti-CCP, antibodies to cyclic citrullinated peptide; IgM RF, immunoglobulin M rheumatoid factor; ESR, erythrocyte sedimentation rate; CRP, C-reactive protein; OR, odds ratio.