|
Descriptive characteristics of study population (n = 1121) at the time of mammography, Nurses' Health Study (1989–1998) |
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| Characteristic |
||
|
|
||
| Mean values |
Mean |
SD |
| Age, y |
58.4 |
7.3 |
| Body mass index, kg/m2 |
25.6 |
4.6 |
| Percentage mammographic density, % |
27.1 |
20.6 |
| Frequenciesa |
N |
% |
| Menopausal/hormone status |
||
| Premenopausal |
217 |
19.4 |
| Postmenopausal/never user |
371 |
33.1 |
| Postmenopausal/past user |
317 |
28.3 |
| Postmenopausal/current user |
216 |
19.3 |
| Alcohol consumption |
||
| None |
327 |
31.8 |
| <5 g/day |
346 |
33.6 |
| 5 to 14.9 g/day |
221 |
21.5 |
| 15+ g/day |
135 |
13.1 |
| Parity/age at first birth |
||
| Nulliparous |
83 |
7.5 |
| Parous/<25 years |
549 |
49.6 |
| Parous/25 to 29 years |
382 |
34.5 |
| Parous/>30 |
93 |
8.4 |
| Prior benign breast disease |
465 |
41.5 |
| Family history of breast cancer |
135 |
12.0 |
|
a Numbers may not be added to total due to missing data. | ||
Tamimi et al. Breast Cancer Research 2008 10:R66 doi:10.1186/bcr2127 |
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