| Demographic/characteristic | Abatacept + MTX (n = 156) | Placebo + MTX (n = 110) | Infliximab + MTX (n = 165) |
| Age, years (SD) | 49.0 (12.5) | 49.4 (11.5) | 49.1 (12.0) |
| Gender, % female | 83.3 | 87.3 | 82.4 |
| Race, % Caucasian | 80.8 | 76.4 | 80.6 |
| Geographic origin: | |||
| North America, n (%) | 16 (10.3) | 10 (9.1) | 15 (9.1) |
| South America, n (%) | 93 (59.6) | 66 (60.0) | 96 (58.2) |
| Europe, n (%) | 39 (25.0) | 29 (26.4) | 39 (23.6) |
| Rest of the world, n (%) | 8 (5.1) | 5 (4.5) | 15 (9.1) |
| Disease duration, years (SD) | 7.9 (8.5) | 8.4 (8.6) | 7.3 (6.2) |
| Tender joints, n (SD) | 31.6 (13.9) | 30.3 (11.7) | 31.7 (14.5) |
| Swollen joints, n (SD) | 21.3 (8.6) | 20.1 (7.0) | 20.3 (8.0) |
| Erythrocyte sedimentation rate, mm/h (SD) | 49.4 (31.2) | 47.0 (32.6) | 47.8 (30.4) |
| C-reactive protein levels, mg/dl (SD) | 3.1 (2.7) | 2.7 (2.6) | 3.3 (3.2) |
| DAS28 (ESR), n (SD) | 6.9 (1.0) | 6.8 (1.0) | 6.8 (0.9) |
| HAQ-DI, 0–3 (SD) | 1.8 (0.6) | 1.8 (0.7) | 1.7 (0.7) |
| Rheumatoid factor positive, n (%) | 136 (87.2) | 85 (77.3) | 140 (84.8) |
| Concomitant medications | |||
| Total patients on concomitant medications, n (%) | 156 (100) | 110 (100) | 165 (100) |
| MTX, n (%) | 156 (100) | 110 (100) | 164 (99.4) |
| Dose, mg/week (SD) | 16.5 (3.7) | 16.6 (3.7) | 16.3 (3.6) |
| Duration, months (SD) | 18.3 (20.0) | 23.7 (25.6) | 23.6 (26.8) |
| Corticosteroids, n (%) | 118 (75.6) | 77 (70.0) | 118 (71.5) |
| NSAIDs, n (%) | 133 (85.3) | 93 (84.5) | 142 (86.1) |
MTX, methotrexate; DAS28 (ESR), Disease Activity Score 28 (based on erythrocyte sedimentation rate levels); HAQ-DI, Health Assessment Questionnaire Disability Index; NSAID, non-steroidal anti-inflammatory drug.