Table 2 Description of individuals with complete information
From: A genome-wide linkage study of mammographic density, a risk factor for breast cancer
| Â | All sites | Australia | Northern California | Ontario |
|---|---|---|---|---|
Women, number | 3,253 | 1,537 | 579 | 1,137 |
Age at mammogram, year | 52.8 (8.7) | 54.1 (8.9) | 51.1 (8.3) | 52.0 (8.3) |
Self-reported ethnicity, n (%) | Â | Â | Â | Â |
Non-Hispanic white | 2,843 (87.4) | 1,495 (97.3) | 255 (44.0) | 1,093 (96.1) |
Black | 89 (2.7) | 0 | 89 (15.5) | 0 |
East Asian | 127 (3.9) | 0 | 119 (20.6) | 8 (0.7) |
Other/Mixed | 189 (5.8) | 38 (2.2) | 116 (20.0) | 35 (3.1) |
Age at menarche, year | 12.9 (1.5) | 13.0 (1.6) | 12.8 (1.5) | 12.8 (1.5) |
Pregnant ever, n (%) | 2,889 (88.8) | 1,402 (91.2) | 496 (85.7) | 991 (87.2) |
Number of live births, n (%) | Â | Â | Â | Â |
0 | 489 (15.0) | 187 (12.2) | 123 (21.2) | 179 (15.7) |
1 | 314 (9.7) | 115 (7.5) | 88 (15.2) | 111 (9.8) |
2 | 1,165 (35.8) | 534 (34.7) | 185 (32.0) | 446 (39.2) |
3+ | 1,285 (39.5) | 701 (45.6) | 183 (31.6) | 401 (35.3) |
Postmenopausal, n (%) | 2,129 (65.5) | 1,033 (67.2) | 380 (65.6) | 716 (63.0) |
Past or current hormone therapy use, n (%) | 1,248 (38.4) | 572 (37.2) | 262 (45.3) | 414 (36.4) |
Body mass index | 26.1 (5.4) | 26.2 (5.3) | 26.4 (6.1) | 25.9 (5.1) |
Personal history of breast cancer, n (%) | 601 (18.5) | 84 (5.5) | 221 (38.2) | 296 (26.0) |
PMD | 30.3 (17.6) | 28.1 (16.1) | 33.4 (18.2) | 31.6 (18.9) |