Odds ratios and 95% confidence intervals from conditional logistic regression of breast cancer risk; results from univariate and multivariate analysis
| Risk factor | OR (95% CI) | |
|---|---|---|
| Crude | Adjusted* | |
| *In the multivariate modelling, each variable was controlled for all other variables in the model (cumulative radiation dose, number of fertile years, parity, family history of breast cancer, alcohol consumption, disruption of sleep rhythm, and menstrual cycle). | ||
| Cumulative radiation dose (per 10 mSv) | 0.99 (0.83 to 1.19) | 0.93 (0.68 to 1.27) |
| Number of fertile years (per 5 years) | 1.33 (0.70 to 2.52) | 1.51 (0.54 to 4.19) |
| Parity | ||
| No children | 1.00 | 1.00 |
| 1 child or more | 0.64 (0.23 to 1.79) | 1.10 (0.23 to 4.85) |
| Family history of breast cancer | ||
| No | 1.00 | 1.00 |
| Yes | 2.67 (1.00 to 7.08) | 5.52 (1.44 to 21.23) |
| Alcohol consumption | ||
| 0–7 units per a week | 1.00 | 1.00 |
| 7.1–28 units per a week | 2.67 (0.96 to 7.38) | 4.11 (1.01 to 16.72) |
| Disruption of sleep rhythm | ||
| Never or rarely | 1.00 | 1.00 |
| Sometimes or often | 1.72 (0.70 to 4.27) | 1.52 (0.49 to 4.74) |
| Disruption of menstrual cycle | ||
| Never or rarely | 1.00 | 1.00 |
| Sometimes or often | 0.71 (0.26 to 1.96) | 0.56 (0.12 to 2.61) |