Risk of developing of rheumatoid arthritis across groups exposed to different number of types of prolonged repetitive physical workloads in the EIRA
| Number of PW exposures | Cases/controls | OR* (95% CI) | OR† (95% CI) |
|---|---|---|---|
| 0 | 206/520 | 1.0 (ref) | 1.0 (ref) |
| 1 | 596/1283 | 1.2 (1.0 to 1.4) | 1.1 (0.9 to 1.3) |
| 2 | 720/1156 | 1.5 (1.3 to 1.9) | 1.5 (1.2 to 1.8) |
| 3 | 525/706 | 1.9 (1.5 to 2.3) | 1.7 (1.4 to 2.1) |
| 4 | 328/415 | 2.1 (1.6 to 2.6) | 1.9 (1.5 to 2.4) |
| 5 | 298/295 | 2.6 (2.1 to 3.3) | 2.4 (1.9 to 3.0) |
| 6 | 195/153 | 3.6 (2.8 to 4.8) | 3.2 (2.4 to 4.2) |
| p Value for trend | <0.0001 | <0.0001 |
These are exposures 5 years before baseline.
*OR adjusted for age (10 strata), sex and residential area.
†OR adjusted for age (10 strata), sex, residential area and smoking.
EIRA, Epidemiological Investigation of Rheumatoid Arthritis; PW, physical workload; ref, reference.