Table 1.
Baseline characteristics (n = 174)
| Patients with IA (n = 31) | Non-IA patients (n = 143) | p Valuea | |
|---|---|---|---|
| Female sex, n (%) | 25 (81) | 119 (83) | 0.731 |
| Age, years, mean (SD) | 50 (8) | 44 (12) | 0.005 |
| BMI, mean (SD) | 26.8 (4.4) | 27.5 (5.2) | 0.534 |
| SJC44, median (IQR) | 0 (0–0) | 0 (0–0) | – |
| TJC44, median (IQR) | 4 (2–9) | 5 (3–8) | 0.828 |
| RF-positive, n (%) | 9 (31) | 37 (27) | 0.628 |
| ACPA-positive, n (%) | 7 (24) | 19 (14) | 0.161 |
| ESR, median (IQR) | 10.5 (5–22) | 10.5 (5–21) | 0.824 |
| Morning stiffness, minutes, median (IQR) | 30 (30–60) | 30 (15–60) | 0.515 |
| DAS28, mean (SD) | 3.4 (1.1) | 3.3 (1.0) | 0.710 |
| US synovitisb, n (%) | 17 (59) | 44 (32) | 0.007 |
| PD score > 0, n (%) | 9 (31) | 17 (12) | 0.012 |
Abbreviations: ACPA Anti-citrullinated protein antibody, BMI Body mass index, DAS28 Disease Activity Score in 28 joints, ESR Erythrocyte sedimentation rate, IA Inflammatory arthritis, PD Power Doppler, RF Rheumatoid factor, SJC44 Swollen joint count in 44 joints, TJC44 Tender joint count in 44 joints, US Ultrasound
a Depending on the distribution of the data, we used the independent t test or the Wilcoxon-Mann-Whitney test. Frequencies were compared using a chi-square test (p ≤ 0.05)
b US synovitis defined as greyscale grade 2 or 3 and/or presence of PD (≥1)