Characteristic | Category | Cases N = 3628 | Controls N = 5126 | ||
---|---|---|---|---|---|
N | % | N | % | ||
Study type | Population-based or cohort | 2439 | 67.2 | 3895 | 76.0 |
 | Hospital-based | 1189 | 32.8 | 1231 | 24.0 |
Age (years) | < 50 | 432 | 11.9 | 553 | 10.8 |
 | 50–59 | 1150 | 31.7 | 1462 | 28.5 |
 | ≥ 60 | 2046 | 56.4 | 3111 | 60.7 |
Parity | Nulliparous | 431 | 12.1 | 582 | 11.5 |
 | Parous | 3141 | 87.9 | 4459 | 88.5 |
 | Unknown | 56 |  | 85 |  |
Menopausal status | Pre-menopausal | 540 | 15.0 | 878 | 17.4 |
 | Post-menopausal | 3058 | 85.0 | 4194 | 82.6 |
 | Unknown | 30 |  | 54 |  |
Postmenopausal HT use in post-menopausal women | Ever | 1737 | 59.6 | 2116 | 57.4 |
Never | 1179 | 40.4 | 1568 | 42.6 | |
Unknown | 142 | Â | 510 | Â | |
BMI (kg/m2) | < 25 | 1542 | 42.9 | 2095 | 41.3 |
 | ≥ 25 | 2049 | 57.1 | 2982 | 58.7 |
 | Unknown | 37 |  | 49 |  |
Family history breast cancer in first degree relatives | No | 2808 | 81.5 | 3944 | 85.1 |
Yes | 637 | 18.5 | 688 | 14.9 | |
Unknown | 183 | Â | 494 | Â |