Patient demographics of all established and early RA.
| Characteristic | RA > 3 Years, n = 7,413 | RA ≤ 3 Years, n = 3,777 | p (for % difference between established and early RA) |
|---|---|---|---|
| Sex, n (%) | |||
| Male | 1,768 (24.1) | 1,037 (27.8) | < 0.0001 |
| Female | 5,568 (75.9) | 2,698 (72.2) | < 0.0001 |
| Age (mean ± SD) yrs | 60.3 ± 12.8 | 56.5 ± 14.7 | < 0.0001 |
| Disease duration, median yrs | 12 | 1 | < 0.0001 |
| Race/ethnicity, n (%) | |||
| Caucasian | 6,193 (85.4) | 3,150 (85.3) | 0.9015 |
| African American | 323 (4.5) | 168 (4.5) | 0.8189 |
| Asian | 102 (1.4) | 59 (1.6) | 0.4318 |
| Hispanic | 478 (6.6) | 240 (6.5) | 0.8549 |
| Other | 159 (2.2) | 77 (2.1) | 0.7152 |
| Education, n (%) | |||
| Primary/secondary | 3,627 (52.4) | 1,761 (49.8) | 0.0100 |
| College | 3,292 (47.6) | 1,778 (50.2) | 0.0100 |
| Disability index (HAQ) | 0.4 ± 0.5 | 0.3 ± 0.4 | < 0.0001 |
| DAS28 | 3.8 ±1.6 | 3.7 ± 1.6 | 0.1467 |
| TJC | 9.4 ± 10.0 | 10.1 ± 11.2 | 0.0010 |
| SJC | 5.2 ± 5.9 | 5.4 ± 6.4 | 0.0277 |
| MD VAS global (0–100mm) | 26.3 ± 21.7 | 26.2 ± 21.9 | 0.9695 |
| Patient VAS global (0–100 mm) | 31.8 ± 25.2 | 29.9 ± 25.9 | 0.0003 |
| Patient VAS pain (0–100 mm) | 34.2 ± 26.3 | 33.2 ± 26.6 | 0.0702 |
| ESR, mm/h | 26.0 ± 22.4 | 24.8 ± 22.2 | 0.0685 |
| CRP, mg/dl | 3.4 ± 10.3 | 2.9 ± 9.0 | 0.1696 |
| Prednisone, per day* | 3.8 ± 1.5 | 4.1 ± 1.5 | < 0.0001 |
| Number of prior DMARD failed | 1.0 ± 0.7 | 1.0 ± 0.6 | 0.226 |
↵* Prednisone dose is categorical variable where 1 = 1 mg, 2 = 2–2.5 mg, 3 = 3–4 mg, 4 = 5–7 mg, 5 = 7.5–9 mg, 6 = > 10 mg. HAQ: Health Assessment Questionnaire; DAS28: 28 joint disease activity score; TJC: tender joint count; SJC: swollen joint count; VAS: visual analog scale; ESR: erythrocyte sedimentation rate; CRP: C-reactive protein; DMARD: disease modifying antirheumatic drugs.