Table 3. Brisk* walking at baseline in relation to breast cancer overall, ER+ and ER- breast cancer.
| All breast cancer | ER+ breast cancer | ER- breast cancer | |||||
|---|---|---|---|---|---|---|---|
|
| |||||||
| hrs/wk | Cases | Person years | IRR (95% CI) | Cases | IRR (95% CI) | Cases | IRR (95% CI) |
| <1 | 1086 | 470,638 | 1.00 (Ref.) | 544 | 1.00 (Ref.) | 310 | 1.00 (Ref.) |
| 1 | 67 | 31,643 | 0.96 (0.75, 1.22) | 36 | 1.02 (0.72, 1.43) | 23 | 1.10 (0.72, 1.68) |
| 2 | 59 | 32,662 | 0.79 (0.61, 1.03) | 34 | 0.88 (0.62, 1.25) | 14 | 0.63 (0.37, 1.08) |
| 3-4 | 78 | 37,884 | 0.88 (0.69, 1.11) | 36 | 0.77 (0.55, 1.09) | 30 | 1.17 (0.79, 1.71) |
| 5-6 | 40 | 20,299 | 0.84 (0.61, 1.16) | 20 | 0.80 (0.51, 1.27) | 16 | 1.14 (0.68, 1.90) |
| 7+ | 29 | 17,057 | 0.77 (0.53, 1.13) | 16 | 0.83 (0.50, 1.38) | 10 | 0.88 (0.46, 1.68) |
| Ptrend=0.02 | Ptrend=0.08 | Ptrend=0.98 | |||||
*
Walking defined as brisk based on fairly brisk or brisk pace reported on the 2003 or 2005 questionnaire
**
IRRs adjusted for age (single year), time period (questionnaire cycle), BMI (<25, 25-29, ≥30 ), years of education (≤ 12, 13-15, 16, ≥ 17), parity (0, 1, 2, ≥ 3), vegetable/fruit dietary pattern (quintiles), meat/fried foods dietary pattern (quintiles), and vigorous exercise (<1,1-4, ≥5 hours/wk)