| Predictor | n* (%) | Mean DAS28* (SD) | Linear regression coefficient (95% CI) p value | ||
| Base | Improvement | Adjusted† | Difference between drugs | ||
| Etanercept: | Ref | ||||
| RF negative | 22 (9) | 6.63 (1) | 2.69 (1.8) | Ref | |
| RF positive | 219 (91) | 6.63 (1) | 2.43 (1.5) | −0.25 (−0.89 to 0.39) p = 0.44 | |
| Infliximab: | −0.58 (−1.4 to 0.03) p = 0.18 | ||||
| RF negative | 29 (13) | 6.79 (1) | 3.34 (1.6) | Ref | |
| RF positive | 189 (87) | 6.60 (1) | 2.34 (1.6) | −0.83 (−1.40 to −0.27) p = 0.004 | |
| Etanercept: | Ref | ||||
| Anti-CCP negative | 35 (15) | 6.62 (1) | 2.72 (1.4) | Ref | |
| Anti-CCP positive | 206 (85) | 6.64 (1) | 2.40 (1.5) | −0.26 (−0.77 to 0.26) p = 0.33 | |
| Infliximab: | −0.41 (−1.1 to 0.3) p = 0.26 | ||||
| Anti-CCP negative | 41 (19) | 6.62 (1) | 3.07 (1.7) | Ref | |
| Anti-CCP positive | 177 (81) | 6.63 (1) | 2.33 (1.6) | −0.67 (−1.16 to −0.18) p = 0.007 | |
*Figures represent those across the complete subgroup of 642 patients. †Analyses adjusted for baseline DAS28, HAQ, concurrent DMARD therapy and gender.
DAS28, 28-joint Disease Activity Score; DMARD, disease-modifying antirheumatic drug; HAQ, Health Assessment Questionnaire; Ref, reference group.