Characteristics of patients visiting the Early Arthritis Recognition Clinic
| Derivation (n=644) | Validation (n=644) | P values* | |
| Male, n (%) | 190 (30) | 198 (31) | 0.62 |
| Age in years, mean±SD | 52±16 | 51±17 | 0.27 |
| Symptom duration in weeks, median (IQR) | 10 (3–45) | 12 (4–45) | 0.18 |
| Acute onset of symptoms†, n (%) | 252 (39) | 238 (37) | 0.45 |
| Symptoms worst in the early morning, n (%) | 372 (58) | 351 (55) | 0.10 |
| Morning stiffness in minutes, median (IQR) | 10 (0–30) | 10 (0–30) | 0.33 |
| Number of painful joints, median (IQR) | 7 (2–15) | 6 (3–15) | 0.69 |
| Number of patient-reported swollen joints, median (IQR) | 2 (1–5) | 2 (1–5) | 0.19 |
| Difficulty with making a fist, n (%) | 329 (51) | 301 (47) | 0.06 |
| Arthritis present at joint examination by experienced rheumatologist, n (%) | 271 (42) | 252 (39) | 0.28 |
*Unpaired t-tests, χ2 tests and Mann-Whitney U tests were used as appropriate.
†Patients were asked to define onset of symptoms; either acute onset of symptoms or gradual onset of symptoms, see online supplementary appendix S1.