| Patient subgroups according autoantibody status | P values of direct group comparisons | ||||
---|---|---|---|---|---|---|
 | (1) RF−/ACPA− | (2) RF−/ACPA+ | (3) RF+/ACPA− | (4) RF+/ACPA+ | Overall | Pairwise comparisons |
Patients, number | 64 | 29 | 40 | 611 | 0.48 | Not done |
Age, years | 52.0 (13.5) | 49.2 (10.7) | 46.1 (14.6) | 47.5 (13.0) | 0.05 | Not done |
Disease duration, years | 1.0 (1.0) | 0.7 (0.9) | 0.8 (0.9) | 1.0 (1.2) | 0.58 | Not done |
Female, % | 82.8 | 89.7 | 92.5 | 80.0 | 0.15 | Not done |
Rheumatoid factor, U/ml | <15 | 15.0 (0.0) | 170 (199) | 517 (854) | n.d. | Not done |
ACPAs, U/ml | 2.1 (0.3) | 221 (270) | 2.9 (1.1) | 392 (660) | n.d. | Not done |
Health assessment questionnaire | 1.6 (0.6) | 1.7 (0.7) | 1.8 (0.6) | 1.8 (0.7) | 0.11 | Not done |
Disease activity score 28, ESR | 6.9 (1.0) | 6.6 (0.9) | 7.1 (1.2) | 7.1 (1.0) | 0.0025 | (1) vs. (4)*; (2) vs. (3)*; (2) vs. (4)** |
Disease activity score 28, CRP | 5.6 (0.8) | 5.3 (0.8) | 5.9 (1.0) | 5.8 (0.9) | 0.01 | (2) vs. (3)**; (2) vs. (4)** |
Simplified disease activity index | 47.8 (15.0) | 42.3 (12.7) | 53.1 (16.5) | 49.8 (14.7) | 0.0076 | (2) vs. (3)**; (2) vs. (4)** |
Clinical disease activity index | 45.0 (14.7) | 39.7 (12.2) | 49.9 (15.5) | 46.6 (13.8) | 0.0097 | (2) vs. (3)**; (2) vs. (4)** |
Swollen joint count | 14.2 (6.6) | 11.7 (5.9) | 16.7 (6.5) | 14.5 (6.3) | 0.0094 | (2) vs. (3)**; (3) vs. (4)**; (2) vs. (4)** |
Tender joint count | 18.0 (7.0) | 14.8 (5.6) | 19.4 (8.1) | 18.4 (7.1) | 0.02 | (2) vs. (3)*; (2) vs. (4)** |
Pain, VAS | 58.9 (21.2) | 60.9 (21.5) | 61.8 (22.1) | 64.2 (22.5) | 0.15 | Not done |
Patient global assessment, VAS | 64.3 (19.3) | 65.0 (21.6) | 68.4 (21.6) | 69.0 (21.7) | 0.12 | Not done |
Evaluator global assessment, VAS | 64.1 (20.0) | 67.2 (12.3) | 69.6 (16.3) | 68.6 (17.9) | 0.35 | Not done |
ESR | 47.5 (25.4) | 51.4 (29.0) | 54.2 (29.1) | 61.0 (29.5) | 0.0009 | (1) vs. (4)*** |
CRP | 2.7 (2.6) | 2.6 (2.0) | 3.2 (3.5) | 3.3 (2.9) | 0.23 | Not done |
Radiographic score | 5.2 (7.9) | 7.1 (8.3) | 5.77 (11.7) | 7.92 (11.6) | 0.0066 | (1) vs. (4)*; (3) vs. (4)** |