Table 4.
Breast cancer | ||||
e-case1 | e-ctrl.1 | Crude OR (95% CI) | Adj. OR (95% CI) | |
Age at diagnosis | ||||
<50 years | 99 | 444 | 0.96 (0.7–1.2) | 0.8 (0.6–1.1) |
50+ years | 1393 | 2698 | 1.1 (0.99–1.2) | 1.3 (1.1–1.4) |
Education | P eff = 0.0 | P eff = 0.0 | ||
University level | 455 | 1089 | 1.2 (0.96–1.6) | 1.1 (0.7–1.5) |
Lower education | 1037 | 2053 | 1.2 (1.0–1.3) | 1.3 (1.1–1.5) |
Age at menarche | P eff = 0.0 | P eff = 0.0 | ||
<13 years | 764 | 1600 | 1.1 (0.9–1.3) | 1.1 (0.9–1.3) |
13+ years | 728 | 1542 | 1.1 (0.9–1.3) | 1.0 (0.8–1.3) |
Child bearing history | P eff = 0.0 | P eff = 0.0 | ||
0–1 child | 678 | 1167 | 1.1 (0.9–1.3) | 1.1 (0.8–1.4) |
2+ children | 814 | 1975 | 1.0 (0.9–1.2) | 1.0 (0.9–1.2) |
Age at first live birth | P eff = 0.0 | P eff = 0.0 | ||
<= 22 years | 593 | 1255 | 1.1 (0.9–1.3) | 1.2 (0.9–1.5) |
>22 years | 700 | 1554 | 1.2 (0.97–1.4) | 1.2 (0.95–1.5) |
Breast-feeding | P eff = 0.0 | P eff = 0.0 | ||
never | 838 | 1552 | 1.1 (0.9–1.2) | 1.1 (0.91–1.4) |
1 month and more | 654 | 1590 | 1.1 (0.96–1.4) | 1.3 (1.0–1.6) |
OC use | P eff = 0.0 | P eff = 0.0 | ||
never | 461 | 695 | 1.3 (0.99–1.6) | 1.4 (1.0–1.8) |
ever | 1031 | 2447 | 1.2 (1.0–1.3) | 1.1 (0.9–1.3) |
Family history of breast cancer | P eff = 0.0 | P eff = 0.0 | ||
No | 1261 | 2871 | 1.1 (0.97–1.2) | 1.1 (1.0–1.3) |
Yes | 231 | 271 | 5.3 (1.8–15.5) | 6.4 (1.7–24.5) |
Body mass index | P eff = 0.0 | P eff = 0.0 | ||
<25 | 617 | 1546 | 1.2 (0.99–1.5) | 0.99 (0.8–1.3) |
25+ | 875 | 1596 | 1.0 (0.9–1.2) | 1.2 (1.0–1.5) |
P eff = 0.0 | P eff = 0.0 |
Conditional logistic regression: Odds ratios and 95% confidence intervals. Crude and adjusted for age, BMI, family history of breast cancer, childbearing history, age at first live birth, duration of breast-feeding, age at menarche, age at first OC use, education. Analyses for index date 0.5 year prior to cancer diagnosis.
1 e-case, e-ctrl = number of observations for exposed case or exposed control respectively.
P eff = Significance for effect modification