Table 1. The demographic characteristics of 747 breast cancer cases and 716 healthy controls.
| Characteristics | Case (n=747) | Controls (n=716) | P |
|---|---|---|---|
| Age | 49.91±10.28 | 49.55±10.61 | 0.508 |
| Body mass index, BMI | 24.03±3.44 | 23.32±3.13 | <0.001 |
| Age at menarche | 15.37±1.80 | 15.61±1.94 | 0.015 |
| Age at first birth | 23.79±6.11 | 24.00±7.41 | 0.556 |
| Breastfeeding duration | 16.59±13.77 | 11.43±7.48 | <0.001 |
| Menopausal status | |||
| Pre-menopausal | 415 (55.6) | 457 (63.8) | 0.001 |
| Post-menopausal | 332 (44.4) | 259 (36.2) | |
| Family history | |||
| No | 622 (83.3) | 607 (84.8) | 0.431 |
| Yes | 125 (16.7) | 109 (15.2) |
Note: Data presented as the mean ± standard deviation or as number (% of total number)