Table 2.
Differences in the characteristics of nulliparous and parous women. The differences in the characteristics of nulliparous and parous women were investigated for both premenopausal and postmenopausal women separately. For premenopausal women, parous women showed higher age and lower BMI. Parous women showed less likely to smoke and less likely to drink, and were more likely to have hormonal therapy. In contrast, for postmenopausal women, parous women showed higher age and higher BMI. Parous women showed less likely to smoke and less likely to drink and less likely to have hormonal therapy
| 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 |