Characteristics, n (%)a | Cases | Controls | P-valueb |
---|---|---|---|
Ageb, yr | Â | Â | Â |
Mean ± SD | 48.0 ± 24. | 48.0 ± 14.9 | 0.97 |
Body mass index (BMI, kg/m 2 ) | 24.1 ± 5.4 | 20.6 ± 2.5 | 0.0004 |
History of benign breast disease | Â | Â | Â |
No | 241 (58.92) | 154 (45.18) | Â |
Yes | 168 (41.08) | 147 (54.82) | 0.039 |
Use of oral contraceptive | Â | Â | Â |
No | 143 (34.96) | 141 (46.84) | Â |
Yes | 266 (65.04) | 160 (53.16) | 0.001 |