Baseline characteristics
| Characteristic | Arthritis (n=116) | No arthritis (n=232) | aCCP-positive (n=231) | aCCP-negative (n=117) |
|---|---|---|---|---|
| Age in years, mean (±SD) | 48 (±11) | 49 (±12) | 48 (±11)* | 51 (±11)* |
| Female, n (%) | 88 (76) | 180 (77) | 178 (77) | 89 (76) |
| Duration of complaints in months, median (IQR) | 12 (6–36) | 15 (9–36) | 12 (6–34)* | 21 (12–60)* |
| Reported number of painful joints, median (IQR) | 4 (1–9) | 4 (1–8) | 4 (1–9) | 3 (1–7) |
| Number of tender joints at physical examination | 0 (0–4) | 0 (0–2) | 0 (0–3) | 0 (0–2) |
| Antibody status | ||||
| RF-positive, aCCP-negative | 13 (11)† | 104 (45)† | 0 | 117 (100) |
| aCCP-positive, RF-negative | 45 (39) | 86 (37) | 131 (57) | 0 |
| RF and aCCP-positive | 58 (50) | 42 (18) | 100 (43) | 0 |
| SE-positive | 71 (61)† | 110 (47)† | 133 (58)* | 48 (41)* |