Table 1.
Clinical and serological features of the EA patients.
| Feature | Patients (n = 1062) | RA (n = 530) | non-RA (n = 532) | P |
|---|---|---|---|---|
| Women (%) | 818/1062 (77.0) | 420/530 (79.2) | 398/532 (74.8) | 0.09 |
| Years of age at onset, median (IQR) | 52 (40–65) | 54 (43–67) | 49 (37–64) | 2.5 × 10−5 |
| Weeks since onset, median (IQR) | 16 (8–28) | 20 (11–3) | 12 (6–24) | 6.3 × 10−4 |
| Smoker (%) | 444/984 (45.1) | 234/509 (46.0) | 210/475 (44.2) | 0.6 |
| RF positive (%) | 444/1062 (41.8) | 358/530 (67.5) | 86/532 (16.2) | 6.4 × 10−65 |
| anti-CCP positive (%) | 395/1046 (37.8) | 349/526 (66.3) | 46/520 (8.8) | 2.7 × 10−82 |
| anti-CarP positive (%) | 291/1062 (27.4) | 222/530 (41.9) | 69/532 (13.0) | 6.7 × 10−24 |
| DAS28 (median, IQR) | 4.5 (3.4–5.8) | 5.2 (3.9–6.3) | 3.9 (2.9–4.9) | 7.0 × 10−34 |
| Erosions (%) | 93/883 (10.5) | 77/529 (14.6) | 16/354 (4.5) | 6.5 × 10−6 |
Characteristics of the EA patients as a whole and stratified as RA and non-RA at the end of the two-year follow-up. P values correspond to the comparison of the two strata with t-student or chi-squared tests. IQR = interquartile range.