Exploration of potential risk factors for more erosive disease
| Continuous variables | Mean difference (SE)† | GEE OR (95% CI) | p Value‡ |
|---|---|---|---|
| Disease duration | +4.20 (1.60) | 0.95 (0.91 to 0.98) | 0.014 |
| Age | +1.90 (1.80) | 1.01 (0.96 to 1.08) | 0.560 |
| Baseline CRP | −0.02 (0.05) | 0.99 (0.95 to 1.05) | 0.970 |
| Baseline ESR | +1.98 (2.10) | 1.00 (0.99 to 1.00) | 0.440 |
| Dichotomous variables | OR* (95% CI) | GEE OR (95% CI) | p Value‡ |
| Tender joints at baseline (N) | 3.30 (1.40 to 7.60) | 2.50 (1.10 to 5.70) | 0.030 |
| Palpable effusion at baseline | 5.30 (2.30 to 12.0) | 4.40 (2.10 to 8.80) | 0.001 |
| PIP joint vs DIP joint | 1.50 (0.60 to 3.20) | 0.12 (0.78 to 1.03) | 0.790 |
↵* OR and 95% CI obtained by GEE modelling (multivariate analysis).
↵† For each item, the mean difference between groups with erosive and non-erosive disease were calculated (univariate analysis).
↵‡ p Values calculated by GEE modelling.
CRP, C-reactive protein; DIP, distal interphalangeal; ESR, erythrocyte sedimentation rate; GEE OR, generalised estimating equation odds ratio; PIP, proximal interphalangeal; SE, standard error of mean difference.