ORs of developing RA (overall) among subjects exposed to prolonged repetitive physical workload and cold work environment 5 years before baseline
| Cold work environment | |||||||
| Physical workload* | Unexposed | Exposed | |||||
| Cases/controls | OR (95% CI) | Cases/controls | OR (95% CI) | AP (95% CI) | p Value | ||
| Bending/turning | Unexposed | 804/1799 | 1.0 (ref.) | 84/88 | 2.1 (1.5 to 2.9) | −0.2 (−0.6 to 0.1) | 0.190 |
| Exposed | 1376/1925 | 1.5 (1.3 to 1.7) | 313/339 | 2.1 (1.7 to 2.5) | |||
| Repetitive hand/finger movements | Unexposed | 611/1223 | 1.0 (ref.) | 131/193 | 1.4 (1.1 to 1.8) | 0.3 (0.1 to 0.5) | <0.001 |
| Exposed | 1566/2499 | 1.3 (1.2 to 1.5) | 266/234 | 2.6 (2.1 to 3.2) | |||
| Carry more than 10 kg | Unexposed | 1152/2265 | 1.0 (ref.) | 49/60 | 1.7 (1.1 to 2.5) | 0.0 (−0.4 to 0.3) | 0.871 |
| Exposed | 1026/1462 | 1.4 (1.2 to 1.5) | 348/367 | 2.0 (1.7 to 2.4) | |||
| Hands below knee level | Unexposed | 1846/3316 | 1.0 (ref.) | 172/201 | 1.6 (1.3 to 2.0) | −0.1 (−0.3 to 0.2) | 0.687 |
| Exposed | 331/406 | 1.4 (1.2 to 1.7) | 223/224 | 1.9 (1.6 to 2.4) | |||
| Vibration | Unexposed | 1979/3407 | 1.0 (ref.) | 175/211 | 1.5 (1.2 to 1.8) | 0.2 (−0.1 to 0.4) | 0.127 |
| Exposed | 202/316 | 1.2 (1.0 to 1.5) | 221/212 | 2.0 (1.6 to 2.5) | |||
| Hands above shoulder level | Unexposed | 1682/3146 | 1.0 (ref.) | 163/216 | 1.4 (1.0 to 1.8) | 0.1 (−0.1 to 0.4) | 0.226 |
| Exposed | 495/578 | 1.5 (1.3 to 1.8) | 234/210 | 2.3 (1.9 to 2.8) | |||
Baseline is the year when the participants were recruited (ie, at the time when the patients were diagnosed).
*Missing information on 126 (3.4%) cases and 297 (5.0%) controls.
OR adjusted for age (10 strata), sex, residential area and recruitment time period (1996–2006 and 2006–2014).
AP, attributable proportion due to interaction; RA, rheumatoid arthritis.