Table 2.
Some characteristics of 121 000 respondents in the Million Women Study
| Characteristic | Percentage |
| Age at screening (years) | |
| 49 | 4.9 |
| 50-54 | 37.9 |
| 55-59 | 29.1 |
| 60-64 | 25.0 |
| 65+ | 2.3 |
| Use of hormone replacement therapy | |
| Ever | 47.2 |
| Never | 51.4 |
| Missing | 1.4 |
| Number of children | |
| 0 | 11.3 |
| 1 | 13.1 |
| 2 | 41.7 |
| 3 | 21.8 |
| 4 | 7.8 |
| 5 | 2.5 |
| 6+ | 1.4 |
| Missing | 0.3 |
| Age at birth of first child (years) | |
| <20 | 12.6 |
| 20-24 | 46.0 |
| 25-29 | 29.0 |
| 30-34 | 8.0 |
| 35+ | 2.5 |
| Missing | 1.8 |
| Past use of oral contraceptives | |
| Yes | 53.6 |
| No | 44.7 |
| Missing | 1.7 |
| Smoking history | |
| Never | 50.3 |
| Current | 18.1 |
| Ex-smoker | 26.4 |
| Missing | 5.3 |