Baseline characteristics of patients receiving biological agents and of the control groups
| Variable | Biological agents | Control group | ||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Etanercept | Infliximab | Anakinra | Total | Leflunomide only | Leflunomide + methotrexate | |||||||
| Variables are mean (SD), median (interquartile range), of per cent. | ||||||||||||
| DAS28, 28 joint disease activity score; DMARD, disease modifying antirheumatic drug; ESR, erythrocyte sedimentation rate; FFbH, Hannover functional status questionnaire; IQR, interquartile range. | ||||||||||||
| n | 511 | 343 | 70 | 599 | 120 | 141 | ||||||
| Age (years) | 53.7 (12.6) | 53.6 (12.6) | 54.3 (11.6) | 56.5 (11.4) | 58.0 (11.1) | 57.4 (11.2) | ||||||
| Female | 77.9% | 71.1% | 77.1% | 82.8% | 85.8% | 78.0% | ||||||
| Disease duration (years) | 9.0 (5.0 to 16.5) | 8.5 (4.0 to 14.0) | 13.0 (7.0 to 22.0) | 6.0 (3.0 to 13.0) | 9.0 (4.0 to 17.0) | 7.0 (3.0 to 12.0) | ||||||
| Rheumatoid factor positive | 80.6% | 79.0% | 77.1% | 75.0% | 82.5% | 75.9% | ||||||
| Erosive disease | 87.4% | 87.4% | 91.2% | 70.0% | 77.3% | 78.8% | ||||||
| Swollen joint count | 10.4 (6.3) | 10.7 (6.5) | 10.2 (6.3) | 7.7 (5.3) | 7.4 (5.3) | 8.5 (5.3) | ||||||
| Tender joint count | 13.3 (7.5) | 12.6 (7.6) | 12.6 (7.1) | 10.0 (6.6) | 10.6 (6.3) | 10.9 (6.9) | ||||||
| ESR (mm/h) | 34.0 (20.0 to 54.0) | 35.0 (17.0 to 58.0) | 37.0 (18.5 to 56.0) | 24.0 (14.0 to 40.0) | 28.0 (16.0 to 44.0) | 26.0 (16.0 to 40.0) | ||||||
| C reactive protein (mg/l) | 20.0 (7.0 to 44.0) | 20.0 (8.0 to 50.0) | 21.0 (8.1 to 35.5) | 11.0 (4.0 to 25.0) | 14.0 (7.0 to 24.0) | 12.0 (5.0 to 28.1) | ||||||
| DAS28 | 6.1 (1.2) | 6.0 (1.2) | 6.1 (1.2) | 5.4 (1.2) | 5.5 (1.2) | 5.6 (1.1) | ||||||
| FFbH | 52.8 (23.4) | 53.8 (21.6) | 52.2 (24.2) | 63.5 (22.0) | 59.1 (21.2) | 64.0 (21.8) | ||||||
| Number of previous DMARDs | 3.9 (1.7) | 3.7 (1.7) | 4.2 (2.0) | 2.1 (1.2) | 2.4 (1.4) | 2.2 (1.2) | ||||||
| DMARDs ever | ||||||||||||
| Methotrexate | 91.2% | 92.1% | 78.6% | 68.7% | 94.2% | 90.7% | ||||||
| Leflunomide | 72.5% | 66.6% | 78.6% | 12.5% | 1.7% | 13.6% | ||||||
| Sulfasalazine | 61.9% | 59.8% | 62.9% | 43.9% | 46.7% | 42.9% | ||||||
| Antimalarials | 45.4% | 43.7% | 52.9% | 30.0% | 28.3% | 32.1% | ||||||
| Parenteral gold | 36.9% | 36.7% | 52.9% | 26.9% | 37.5% | 20.7% | ||||||
| Azathioprine | 21.8% | 18.5% | 28.6% | 6.2% | 8.3% | 7.1% | ||||||
| Ciclosporine A | 20.8% | 18.2% | 22.9% | 3.0% | 5.0% | 2.1% | ||||||
| Other | 12.6% | 9.1% | 11.4% | 7.7% | 9.2% | 6.4% | ||||||
| Biological agents ever | 9.2% | 16.4% | 30.0% | 2.7% | 4.2% | 1.4% | ||||||