Risk of developing ACPA-positive RA and ACPA-negative RA among participants exposed to prolonged repetitive physical workload
| Types of physical workload | ACPA-positive RA | ACPA-negative RA | |||||||
|---|---|---|---|---|---|---|---|---|---|
| Baseline | 5 years before baseline | Baseline | 5 years before baseline | ||||||
| Cases/controls | OR* (95% CI) | Cases/controls | OR* (95% CI) | Cases/controls | OR* (95% CI) | Cases/controls | OR* (95% CI) | ||
| Bending/turning | Unexposed | 646/1941 | 1.0 (ref) | 654/2039 | 1.0 (ref) | 277/1941 | 1.0 (ref) | 309/2039 | 1.0 (ref) |
| Exposed | 956/2067 | 1.4 (1.3 to 1.6) | 1261/2531 | 1.6 (1.4 to 1.8) | 490/2067 | 1.6 (1.4 to 1.9) | 664/2531 | 1.7 (1.5 to 2.0) | |
| Repetitive hand/finger movements | Unexposed | 471/1351 | 1.0 (ref) | 559/1546 | 1.0 (ref) | 207/1351 | 1.0 (ref) | 265/1546 | 1.0 (ref) |
| Exposed | 1129/2652 | 1.2 (1.1 to 1.4) | 1355/3020 | 1.2 (1.1 to 1.4) | 562/2652 | 1.4 (1.2 to 1.7) | 705/3020 | 1.4 (1.2 to 1.6) | |
| Lift or carry more than 10 kg | Unexposed | 865/2418 | 1.0 (ref) | 871/2496 | 1.0 (ref) | 409/2418 | 1.0 (ref) | 413/2496 | 1.0 (ref) |
| Exposed | 735/1585 | 1.3 (1.2 to 1.5) | 1043/2077 | 1.5 (1.3 to 1.7) | 360/1585 | 1.4 (1.2 to 1.6) | 559/2077 | 1.6 (1.4 to 1.9) | |
| Precision work | Unexposed | 1428/3584 | 1.0 (ref) | 1702/4061 | 1.0 (ref) | 670/3584 | 1.0 (ref) | 834/4061 | 1.0 (ref) |
| Exposed | 169/398 | 1.1 (0.9 to 1.3) | 208/487 | 1.0 (0.9 to 1.2) | 96/398 | 1.3 (1.0 to 1.7) | 136/487 | 1.4 (1.1 to 1.7) | |
| Hands below knee level | Unexposed | 1295/3448 | 1.0 (ref) | 1468/3827 | 1.0 (ref) | 613/3448 | 1.0 (ref) | 747/3827 | 1.0 (ref) |
| Exposed | 304/546 | 1.5 (1.3 to 1.8) | 447/736 | 1.6 (1.4 to 1.9) | 152/546 | 1.6 (1.3 to 1.9) | 221/736 | 1.6 (1.3 to 1.8) | |
| Hands above shoulder level | Unexposed | 1225/3331 | 1.0 (ref) | 1346/3675 | 1.0 (ref) | 577/3331 | 1.0 (ref) | 682/3675 | 1.0 (ref) |
| Exposed | 375/668 | 1.6 (1.4 to 1.8) | 567/893 | 1.8 (1.6 to 2.0) | 193/668 | 1.7 (1.4 to 2.0) | 290/893 | 1.7 (1.5 to 2.0) | |
| Vibration | Unexposed | 1357/3492 | 1.0 (ref) | 1571/3927 | 1.0 (ref) | 636/3492 | 1.0 (ref) | 782/3927 | 1.0 (ref) |
| Exposed | 242/499 | 1.3 (1.1 to 1.6) | 344/634 | 1.5 (1.3 to 1.8) | 132/499 | 1.5 (1.2 to 1.9) | 191/634 | 1.6 (1.3 to 1.9) | |
*OR adjusted for age (10 strata), sex and residential area; baseline is the year when the participants were diagnosed with RA.
ACPA, anticitrullinated protein antibody; RA, rheumatoid arthritis; ref; reference.