Table 1 Characteristics of 102,927 women from the Generations Study, recruited 2003–2013
From: Smoking and risk of breast cancer in the Generations Study cohort
| Study population | No. of subjects | % |
|---|---|---|
| Year of birth | ||
| 1908–1939 | 5917 | 5.8 |
| 1940–1949 | 21,488 | 20.9 |
| 1950–1959 | 24,735 | 24.0 |
| 1960–1969 | 23,749 | 23.1 |
| 1970–1996 | 27,038 | 26.3 |
| Year of recruitment | ||
| 2003–2005 | 33,807 | 32.9 |
| 2006–2007 | 48,489 | 47.1 |
| 2008–2013 | 20,631 | 20.0 |
| Age at recruitment, years | ||
| 16–34 | 23,289 | 22.6 |
| 35–44 | 23,116 | 22.5 |
| 45–54 | 24,385 | 23.7 |
| 55–64 | 23,837 | 23.2 |
| 65–74 | 7308 | 7.1 |
| 75–102 | 992 | 1.0 |
| Age at menarche, years | ||
| 7–11 | 20,658 | 20.1 |
| 12–14 | 62,291 | 60.5 |
| 15–19 | 9353 | 9.1 |
| Not known or anomalousa | 10,625 | 10.3 |
| Family history of breast cancer in first-degree relatives | ||
| No | 87,030 | 84.6 |
| Yes | 15,897 | 15.4 |
| Smoking status, at entry into cohort | ||
| Never smoked | 66,013 | 64.1 |
| Current smoker | 8491 | 8.3 |
| Former smoker | 28,300 | 27.5 |
| Ever smoker, status unknown at this time | 123 | 0.1 |
| Alcohol consumption, at entry into cohort | ||
| Never regular | 10,574 | 10.3 |
| Current drinker (< 60 g/day) | 63,690 | 61.9 |
| Current drinker (≥ 60 g/day) | 1280 | 1.2 |
| Current drinker, amount unknown | 4306 | 4.2 |
| Former drinker | 13,513 | 13.1 |
| Ever drinker, status unknown at this time | 9564 | 9.3 |
| Total number of subjects | 102,927 | 100.0 |