Controls (n = 685) | Cases (n = 414) | |||
---|---|---|---|---|
Age, years at mammography | ||||
Mean (SD) | 59.5 (6.6) | 67.5 (12.7) | ||
Missing, n | 6 | 2 | ||
Ethnicity | ||||
White, n (%) | 520 (76.5) | 370 (90.5) | ||
Other, n (%) | 160 (23.5) | 39 (9.5) | ||
Missing, n | 5 | 5 | ||
Educational level | ||||
None, n (%) | 15 (2.2) | 10 (3.7) | ||
Primary, n (%) | 20 (3.0) | 7 (2.6) | ||
Secondary, n (%) | 297 (43.9) | 186 (68.4) | ||
University, n (%) | 344 (50.9) | 69 (25.4) | ||
Missing, n | 9 | 142 | ||
Body mass index at mammography a , kg/m 2 | ||||
Mean (SD) | 26.1 (5.6) | 26.4 (4.9) | ||
Missing, n | 29 | 46 | ||
Age at menarche, yrs | ||||
<12, n (%) | 141 (21.0) | 81 (21.3) | ||
12, n (%) | 130 (19.4) | 78 (20.5) | ||
13, n (%) | 168 (25.0) | 87 (22.8) | ||
14+, n (%) | 232 (34.6) | 135 (35.4) | ||
Missing, n | 14 | 33 | ||
Menopausal status at mammography b | ||||
Pre- and perimenopausal, n (%) | 91 (13.3) | 55 (13.3) | ||
Postmenopausal, n (%) | 591 (86.7) | 358 (86.7) | ||
Missing, n | 3 | 1 | ||
Ever use of oral contraceptives | ||||
Yes, n (%) | 472 (70.5) | 216 (55.2) | ||
No, n (%) | 198 (29.6) | 175 (44.8) | ||
Missing, n | 15 | 23 | ||
Ever use of hormonal therapy | ||||
Yes, n (%) | 208 (31.2) | 143 (36.8) | ||
No, n (%) | 459 (68.8) | 246 (63.2) | ||
Missing, n | 18 | 25 | ||
Nulliparity | ||||
No, n (%) | 467 (69.1) | 343 (84.1) | ||
Yes, n (%) | 209 (30.9) | 65 (15.9) | ||
Missing, n | 9 | 6 | ||
Number of children c , n (%) | ||||
1 to 2 | 301 (65.4) | 218 (64.9) | ||
2 to 3 | 126 (27.4) | 105 (31.3) | ||
5+ | 33 (7.2) | 13 (3.9) | ||
Age at first birth, yrs c , n (%) | ||||
<20 | 83 (18.1) | 25 (7.7) | ||
20 to 30 | 258 (56.3) | 213 (65.7) | ||
30+ | 117 (25.6) | 86 (26.5) | ||
Ever breastfed c , n (%) | ||||
Yes | 358 (77.2) | 224 (74.7) | ||
No | 106 (22.8) | 76 (25.3) |