Table 1 Baseline clinical and MRI characteristics of patients included in the discovery and validation cohorts
Discovery cohort (n = 225) | Validation cohort (n = 209) | p value | |
|---|---|---|---|
Age in years, mean (SD) | 44 (13) | 43 (12) | 0.26 |
Female, n (%) | 174 (77) | 165 (79) | 0.77 |
Symptom duration in weeks, med (IQR) | 17 (9–32) | 20 (9–44) | 0.28 |
Localisation of initial symptoms | 0.39 | ||
Small joints, n (%) | 189 (84) | 165 (79) | |
Small and large joints, n (%) | 22 (10) | 26 (13) | |
Large joints, n (%) | 13 (6) | 17 (8) | |
Localisation of initial symptoms | 0.76 | ||
Upper extremities, n (%) | 162 (72) | 134 (70) | |
Upper and lower extremities, n (%) | 39 (17) | 34 (18) | |
Lower extremities, n (%) | 23 (10) | 24 (13) | |
Symmetrical localisation of initial symptoms, n (%) | 166 (74) | 127 (70) | 0.35 |
Morning stiffness ≥ 60 min, n (%) | 72 (36) | 62 (34) | 0.83 |
68-TJC, med (IQR) | 6 (3–10) | 5 (2–10) | 0.23 |
Fulfilling the EULAR definition of CSA, n (%) | 153 (68) | 131 (63) | 0.29 |
CRP level in mg/L, med (IQR) | 3 (3–5) | 3 (3–4) | 0.59 |
ESR level in mg/L, med (IQR) | 6 (2–13) | 6 (2–14) | 0.12 |
RF, n (%) | 46 (20) | 41 (20) | 0.92 |
ACPA, n (%) | 28 (12) | 30 (14) | 0.66 |
MRI-detected presence of subclinical inflammation (MRI positivity), n (%) | 114 (51) | 74 (35) | 0.002 |