From: Impact of childbirth history on dense breast in mammographic screening: a cross-sectional study
 | Premenopausal women (n = 7612) | Postmenopausal women (n = 9252) | ||||
---|---|---|---|---|---|---|
 | Nulliparous (n = 3878) | Parous (n = 3734) | p | Nulliparous (n = 3279) | Parous (n = 5973) | p |
Age mean (SD) | 44.12 (5.95) | 45.06 (5.04) |  < 0.001 | 58.93 (7.57) | 62.92 (8.45) |  < 0.001 |
BMI mean (SD) | 21.51 (3.45) | 21.17 (3.03) |  < 0.001 | 21.56 (3.65) | 21.70 (3.29) |  < 0.001 |
Smoking status |  |  |  < 0.001 |  |  |  < 0.001 |
 Never | 3079 (79.4%) | 3112 (83.3%) | 2564 (78.2%) | 5121 (85.7%) | ||
 Past | 537 (13.8%) | 517 (13.8%) | 541 (16.5%) | 704 (11.8%) | ||
 Current | 262 (6.8%) | 105 (2.8%) | 174 (5.3%) | 148 (2.5%) | ||
Alcohol status |  |  |  < 0.001 |  |  |  < 0.001 |
 None | 1627 (42.0%) | 1878 (50.3%) | 1704 (52.0%) | 3601 (60.3%) | ||
 Occasional | 640 (16.5%) | 544 (14.6%) | 418 (12.7%) | 819 (13.7%) | ||
 Regular | 1611 (41.5%) | 1312 (35.1%) | 1157 (35.3%) | 1553 (26.0%) | ||
Family history of breast cancer | 772 (19.9%) | 715 (19.1%) | 0.404 | 596 (18.2%) | 1009 (16.9%) | 0.119 |
Hormonal therapy | 515 (13.8%) | 576 (15.8%) | 0.017 | 586 (18.6%) | 715 (12.5%) |  < 0.001 |