Characteristics of FDRs with ultrasound (MSUS)
| Non-active MSUS (n=177) | Active MSUS (n=96) | Univariable† OR (95% CI) | |
| Age, years, median (IQR) | 50 (38–59) | 52 (44–61) | 1.0 (1.0 to 1.0)* |
| Gender (female), n (%) | 135 (76) | 70 (73) | 0.8 (0.5 to 1.5) |
| Tobacco smoking current, n (%)‡ | 36 (22) | 17 (21) | 0.9 (0.5 to 1.8) |
| Tobacco smoking ever, n (%) | 80 (45) | 46 (48) | 1.1 (0.7 to 1.8) |
| Alcohol regular consumption, n (%) | 51 (29) | 33 (34) | 1.3 (0.8 to 2.2) |
| Body mass index, median (IQR) | 24 (21–27) | 23 (22–25) | 0.9 (0.9 to 1.0) |
| Activity (frequent manual activity) | 20 (11) | 17 (18) | 1.7 (0.8 to 3.4) |
| ACPA positivity, n (%) | 15 (8) | 8 (8) | 0.9 (0.4 to 2.4) |
| SE (one or two alleles), n (%) | 90 (51) | 40 (42) | 0.71 (0.5 to 1.1) |
| Time since first enrolment in SCREEN-RA | 0 (0–2.5) | 0 (0–2.4) | 1.1 (0.9 to 1.2) |
Active MSUS defined as a total B-mode score >8, including at least one joint with synovitis of grade 2 or 3, or Doppler score greater than 1.
*P<0.05.
†Univariable logistic regression analysis.
‡A total of 10% of observations were missing.
ACPA, anticitrullinated protein autoantibodies; FDRs, first-degree relatives; MSUS, musculoskeletal ultrasound; SE, shared epitope.