Table 1.
Baseline characteristics, treatment of subjects and frequency of diagnoses in the 2 groups. Values are number (percentage) unless otherwise indicated. Statistics for dosage are presented as mean (SD) mg/week
| Parameter | Group A (n = 872) |
Valid n | Group B (n = 681) |
Valid n |
|---|---|---|---|---|
| Female sex | 483 (55) | 509 (75) | ||
| Age at surgery, mean (SD) | 55 (18) | 59 (15) | ||
| Disease duration at surgery, mean (SD) in years | 19.5 (12) | 341 | 21.5 (13) | 587 |
| Mean HAQ (health assessment questionnaire) (0–3) | 1.3 (0.7) | 324 | 1.3 (0.7) | 511 |
| Mean CDAI (clinical disease activity index) (0–100) | 14 (9.0) | 302 | 13 (8.7) | 528 |
| ESR, mean (SD), mm/h | 27 (22) | 305 | 25 (19) | 469 |
| CRP, mean (SD), mg/L | 19 (29) | 448 | 13 (21) | 602 |
| Previous biological DMARD | 84 (10) | 106 (16) | ||
| Length of treatment with the current biological DMARD before surgery, mean (SD), years | 2.5 (1.9) | 247 | 3.2 (2.6) | 249 |
| Treatment | ||||
| Prednisolone | 368 (46) | 848 | 307 (47) | 675 |
| Dosage prednisolone for treated patient | 41 (32) | 385 | 42 (25) | 318 |
| Methotrexate | 364 (45) | 849 | 332 (51) | 675 |
| Dosage of methotrexate for treated patient | 14.6 (5.4) | 390 | 15.6 (5.2) | 340 |
| DMARDs other than methotrexate | 207 (26) | 849 | 140 (21) | 675 |
| Biological DMARDs a | 256 (32) | 849 | 252 (38) | 675 |
| TNF inhibitor | 249 (31) | 849 | 236 (36) | 675 |
| Dosage of infliximab for treated patient | 58.7 (71) | 58 | 56.3 (29) | 40 |
| Dosage of etanercept for treated patient | 44.8 (14) | 171 | 48.1 (11) | 136 |
| Dosage of adalimumab for treated patient | 19.6 (8.9) | 41 | 23.0 (7.8) | 66 |
| Biological DMARDs + methotrexate | 145 (18) | 847 | 147 (22) | 675 |
| Diagnosis b | ||||
| Rheumatoid arthritis | 581 (67) | 448 (66) | ||
| Spondyloarthritis incl. ankylosing spondylitis | 32 (4) | 24 (4) | ||
| Psoriatic arthritis | 32 (4) | 35 (5) | ||
| Juvenile idiopathic arthritis | 133 (15) | 64 (9) | ||
| Osteoarthritis | 13 (2) | 20 (3) | ||
| Other rheumatic diagnosis | 80 (9) | 88 (13) | ||
a
In group A, 6 patients were treated with anakinra, and 1 with rituximab. In group B, 11 patients were treated with rituximab, 4 with anakinra, 1 with abatacept, and 1 with tocilizumab.
b
Diagnosis was missing in 1 patient in group A and in 2 patients in group B.