Summary of baseline demographics, clinical characteristics and concomitant medications
| Abatacept + methotrexate | Placebo + methotrexate | |
| (n = 256) | (n = 253) | |
| Age in years, mean (SD) | 50.1 (12.4) | 49.7 (13.0) |
| Gender, % female | 76.6 | 78.7 |
| Race, % white | 78.9 | 86.6 |
| Geographical region, n (%) | ||
| North America, n (%) | 46 (18.0) | 40 (15.8) |
| South America, n (%) | 103 (40.2) | 102 (40.3) |
| Europe, n (%) | 88 (34.4) | 95 (37.5) |
| Rest of world, n (%) | 19 (7.4) | 16 (6.3) |
| Disease duration, mean months (SD) | 6.2 (7.5) | 6.7 (7.1) |
| Tender joints, mean (SD) | 31.3 (14.8) | 30.8 (14.0) |
| Swollen joints, mean (SD) | 22.9 (11.3) | 21.9 (10.1) |
| CRP levels, mg/dl, mean (SD) | 3.1 (3.1) | 3.6 (5.0) |
| DAS28 (CRP)*, mean (SD) | 6.3 (1.0) | 6.2 (1.0) |
| HAQ-DI (0–3)†, mean (SD) | 1.7 (0.7) | 1.7 (0.7) |
| RF positive, n (%) | 246 (96.1) | 245 (96.8) |
| Anti-CCP2 positive, n (%) | 236 (92.2) | 217 (85.8) |
| RF and anti-CCP2 positive, n (%) | 227 (88.7) | 211 (83.4) |
| Total x ray score‡, mean (SD) (maximum 290) | 7.5 (9.7) | 6.7 (8.8) |
| Total x ray score‡, median (range) | 3.4 (0.0–57.3) | 3.8 (0.0–54.6) |
| Erosion score‡, mean (SD) (maximum 145) | 5.4 (6.1) | 4.8 (5.4) |
| Erosion score‡, median (range) | 2.9 (0–29.1) | 3.1 (0–36.9) |
| Joint space narrowing‡, mean (SD) (maximum 145) | 2.1 (4.2) | 1.9 (4.0) |
| Joint space narrowing‡, median (range) | 0.2 (0–28.2) | 0.5 (0–28.0) |
| Total patients on antirheumatic concomitant medications at randomisation, n (%) | 243 (94.9) | 236 (93.3) |
| Corticosteroids, oral and/or injectable | 131 (51.2) | 124 (49.0) |
| Corticosteroids, oral <10 mg/day | 95 (37.1) | 86 (34.0) |
| NSAID | 203 (79.3) | 201 (79.4) |
| Other non-biological DMARD | 7 (2.7) | 10 (4.0) |
| Chloroquine | 3 (1.2) | 4 (1.6) |
| Hydroxychloroquine | 4 (1.6) | 5 (2.0) |
| Sulfasalazine | 0 | 1 (0.4) |
*n = 252 for methotrexate; †n = 254 for abatacept plus methotrexate, n = 251 for methotrexate; ‡n = 253 for abatacept plus methotrexate.
CCP2, cyclic citrullinated peptide type 2; CRP, C-reactive protein; DAS28, disease activity score in 28 joints; DMARD, disease-modifying antirheumatic drug; HAQ-DI, health assessment questionnaire disability index; NSAID, non-steroidal anti-inflammatory drug; RF, rheumatoid factor.