| Predictor | n* (%) | Mean DAS28* (SD) | Linear regression, coefficient (95% CI) p value | ||
| Base | Improvement | Adjusted 1† | Adjusted 2‡ | ||
| RF negative | 59 (11) | 6.72 (1) | 3.03 (1.7) | Ref | Ref |
| RF positive | 462 (89) | 6.59 (1) | 2.43 (1.5) | −0.48 (−0.87 to −0.08) p = 0.02 | −0.48 (−0.89 to −0.07) p = 0.02 |
| Anti-CCP negatve | 96 (18) | 6.61 (1) | 2.90 (1.6) | Ref | Ref |
| Anti-CCP positive | 425 (82) | 6.61 (1) | 2.40 (1.5) | −0.39 (−0.71 to −0.07) p = 0.02 | −0.39 (−0.72 to −0.06) p = 0.02 |
| SE negative | 103 (19) | 6.65 (1) | 2.38 (1.5) | Ref | Ref |
| SE positive | 432 (81) | 6.71 (1) | 2.49 (1.5) | 0.07 (−0.25 to 0.39) p = 0.68 | 0.06 (−0.26 to 0.39) p = 0.70 |
| PTPN22 negative | 431 (70) | 6.67 (1) | 2.51 (1.6) | Ref | Ref |
| PTPN22 positive | 188 (30) | 6.72 (1) | 2.48 (1.4) | −0.11 (−0.36 to 0.15) p = 0.41 | −0.13 (−0.39 to 0.13) p = 0.34 |
*Figures represent those across the complete subgroup of 642 patients. †Initial analyses were performed across the entire cohort, adjusting for baseline DAS28, HAQ, concurrent DMARD therapy and gender. ‡Subsequent analyses excluded patients with previous exposure to a biological agent.
DAS28, 28-joint Disease Activity Score; DMARD, disease-modifying antirheumatic drug; HAQ, Health Assessment Questionnaire; Ref, reference group.