Table 2 Age-adjusted and multivariable hazard ratios (95% confidence intervals) of incident breast cancer according to job category and occupational activity
| Â | Number at risk | Number of breast cancer | Person-years | Age-adjusted HR (95%CI) | Multivariable HR (95% CI) | |
|---|---|---|---|---|---|---|
Model 1a | Model 2b | |||||
Job category | ||||||
 1. Manual | 11,464 | 85 | 157,490 | 1.00 (reference) | 1.00 (reference) | 1.00 (reference) |
 2. Office | 2388 | 31 | 33,150 | 1.70 (1.12–2.58) | 1.68 (1.10–2.59) | 1.65 (1.07–2.55) |
 3. Professional | 3727 | 18 | 49,292 | 0.70 (0.42–1.18) | 0.72 (0.42–1.23) | 0.80 (0.47–1.36) |
 4. Unclassified | 1462 | 4 | 15,510 | 0.49 (0.17–1.35) | 0.72 (0.17–2.99) | 0.38 (0.05–2.80) |
Occupational activity | ||||||
 1. Moving | 9453 | 60 | 123,944 | 1.00 (reference) | 1.00 (reference) | 1.00 (reference) |
 2. Standing | 1033 | 4 | 13,364 | 0.61 (0.22–1.68) | 0.47 (0.14–1.52) | 0.46 (0.14–1.49) |
 3. Sitting | 5570 | 63 | 82,071 | 1.57 (1.09–2.25) | 1.51 (1.04–2.19) | 1.45 (1.01–2.12) |