Table 3 |
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|
Relative risk of postmenopausal breast cancer in relation to vigorous and non-vigorous physical activity among US women in the Breast Cancer Detection Demonstration Project (BCDDP: 1987 to 1998)* |
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| Variable |
Category of vigorous or non-vigorous physical activity |
p |
||||
| 1 |
2 |
3 |
4 |
5 |
||
|
|
||||||
| Vigorous physical activity |
||||||
| MET-hours/week |
0 |
0.1 to 48.9 |
49.0 to 70.0 |
70.1 to 126.0 |
126.1 to 588.0 |
|
| Cases |
614 |
236 |
234 |
218 |
204 |
|
| Person-years |
101,276 |
40,772 |
44,949 |
41,072 |
41,772 |
|
| Age-adjusted RR (95% CI) |
1.0 |
1.00 (0.86 to 1.17) |
0.89 (0.76 to 1.03) |
0.90 (0.77 to 1.06) |
0.82 (0.70 to 0.96) |
0.008 |
| Multivariate RR † §(95% CI) |
1.0 |
0.98 (0.84 to 1.14) |
0.88 (0.76 to 1.03) |
0.91 (0.78 to 1.07) |
0.86 (0.73 to 1.01) |
0.06 |
| Multivariate RR ‡ §(95% CI) |
1.0 |
0.98 (0.85 to 1.15) |
0.89 (0.76 to 1.04) |
0.92 (0.79 to 1.08) |
0.87 (0.74 to 1.02) |
0.08 |
| Non-vigorous physical activity |
||||||
| MET hours per week |
0 to 84.0 |
84.1 to 140.0 |
140.1 to 188.0 |
188.1 to 229.0 |
229.1 to 504.0 |
|
| Cases |
317 |
314 |
283 |
287 |
305 |
|
| Person-years |
53,660 |
56,791 |
52,224 |
53,001 |
54,116 |
|
| Age-adjusted RR (95% CI) |
1.0 |
0.94 (0.80 to 1.09) |
0.91 (0.78 to 1.07) |
0.91 (0.77 to 1.06) |
0.95 (0.81 to 1.11) |
0.48 |
| Multivariate RR † || (95% CI) |
1.0 |
0.99 (0.84 to 1.16) |
0.98 (0.83 to 1.16) |
0.97 (0.82 to 1.14) |
1.01 (0.86 to 1.18) |
0.96 |
| Multivariate RR ‡ || (95% CI) |
1.0 |
0.99 (0.84 to 1.16) |
0.99 (0.84 to 1.16) |
0.97 (0.82 to 1.14) |
1.02 (0.87 to 1.19) |
0.86 |
|
|
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|
* CI = confidence interval; MET = metabolic equivalent task; RR = relative risk. † The multivariate model included the following: age at baseline (continuous), family history of breast cancer (any first- or second-degree relative; yes, no or unknown), history of benign breast disease (any benign breast disease prior to study baseline, including during the screening stages; yes or no), breast cancer screening history (women who had undergone a breast biopsy as part of the BCDDP screening but lacked evidence of malignant disease, women who were recommended for surgical consultation as part of the BCDDP but for whom the procedure was not performed, or women who represented a random sample of BCDDP participants who had no surgery or recommendation for surgical consultation during BCDDP screening), height (continuous), age at menarche (≤ 11, 12, 13 or 14+ years of age), age at menopause (age at which menstrual period stopped for at least three continuous months; <47 or 47+ years of age), age at first live birth (continuous), history of oral contraceptive use (yes or no), menopausal hormone therapy (ever or never), education attainment (less than or equal to high school or greater than high school), cigarette smoking (ever or never), and intakes of energy-adjusted dietary fat (continuous) and alcohol (continuous). ‡ Also controlled for body mass index (continuous). §Also controlled for non-vigorous physical activity (quintiles). ||Also controlled for vigorous activity (5 categories). |
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|
Leitzmann et al. Breast Cancer Research 2008 10:R92 doi:10.1186/bcr2190 |
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