Table 1.
Summary of breast cancer risk factor statistics for cases and controls
| Risk factor | Control | Case | p |
|---|---|---|---|
| (a) Continuous risk factors (median, IQR) | |||
| Age (years) | 60 (54–65) | 60 (53–65) | 0.48 |
| Age first child (parous, years) | 24 (19–27) | 24 (19–28) | 0.8 |
| BMI (kg/m2) | 25.9 (23.1–29.8) | 26.5 (23.9–30.3) | 0.005 |
| Density (%) | 26.0 (14.5–38.7) | 29.5 (18.8–42.0) | <0.001 |
| Density residual | 0.01 (−0.65–0.66) | 0.35 (−0.33–1.02) | <0.001 |
| Tyrer–Cuzick model 10 years risk (%) | 2.87 (2.26–3.70) | 3.03 (2.35–4.22) | 0.006 |
| (b) Binary (n, %) | |||
| First‐degree relative (yes, %) | 225 (13.5%) | 65 (16.0%) | 0.21 |
| Parous (yes, %) | 1,401 (84.0%) | 338 (83.5%) | 0.8 |
| White (yes, %) | 1,541 (96.3%) | 375 (95.9%) | 0.8 |
p univariate comparison between cases and controls: continuous risk factor by Wilcoxon test; binary by chi‐square test (with continuity correction); missing data excluded (see Supporting Information).