Baseline† characteristics of rheumatoid arthritis patients on stable therapy (n=6246)
| All patients (n=6246) | Patients with CDAI only (n=2354) | Patient with DAS28 (n=3666) | |
|---|---|---|---|
| Age, years ± SD | 60.2 ± 13.1 | 59.8 ± 13 | 60.6 ± 13* |
| Female gender (%) | 74.5 | 75.6 | 73.9 |
| Current smoker (%) | 14.1 | 14.5 | 13.8 |
| Married (%) | 68.4 | 69.4 | 67.9 |
| Caucasian race/ethnicity (%) | 87.2 | 88.4 | 86.4* |
| College education (%) | 49.9 | 50 | 50.2 |
| BMI, mean ± SD | 28.9 ± 7 | 29 ± 7 | 28.8 ± 6.8 |
| Private insurance (%) | 75 | 75 | 75.8 |
| Medicaid insurance (%) | 5.1 | 4.3 | 4.9 |
| Medicare insurance (%) | 42.2 | 41.1 | 42.8 |
| Disabled (%) | 11.6 | 12.9 | 10.4** |
| Severity of RA, mean ± SD | 2.5 ± 1 | 2.5 ± 1 | 2.5 ± 1 |
| Duration of RA, years ± SD | 11.5 ± 9.9 | 11.7 ± 9.9 | 11.7 ± 9.8 |
| ESR, mean ± SD | 21.8 ± 19 | – | 21.6 ± 18.9 |
| CRP, mean ± SD | 2.1 ± 6.4 | 3.1 ± 8.5 | 1.7 ± 5.6*** |
| HAQ disability index | 0.31 ± 0.4 | 0.34 ± 0.4 | 0.29 ± 0.4*** |
| No methotrexate use | 32.7 | 37 | 29.8*** |
| Methotrexate <15 mg/week (%) | 29.7 | 27.9 | 30.5* |
| Methotrexate ≥15 mg/week (%) | 37.6 | 35.2 | 39.7*** |
| No prednisone use | 76.2 | 72.4 | 79.5*** |
| Prednisone <7.5 mg daily (%) | 19.9 | 22.7 | 17.5*** |
| Prednisone ≥7.5 mg daily (%) | 3.9 | 5 | 3*** |
| TNF inhibitor (%) | 45.3 | 43.7 | 47.3** |
| Other DMARD (%) | 32.7 | 35.4 | 30.8*** |
| ACR functional class I (%) | 50 | 50 | 51.4 |
| ACR functional class II (%) | 39 | 36.7 | 39.6* |
| ACR functional class III (%) | 9.8 | 11.8 | 8*** |
| ACR functional class IV (%) | 1.2 | 1.4 | 1 |
Comparisons of CDAI only and DAS28 patients,
↵* p<0.05,
↵** p≤0.01,
↵*** p≤0.001.
↵† Measured at the third CORRONA visit at which rheumatoid arthritis (RA) medications had been stable.
ACR, American College of Rheumatology; BMI, body mass index; CDAI, clinical disease activity index; CRP, C-reactive protein; DMARD, disease-modifying antirheumatic drug; ESR, erythrocyte sedimentation rate; TNF, tumour necrosis factor.