Table 1 Baseline characteristics in the total study population
Total study population (n = 260,151) | Screening-recruited cohorts (n = 24,727) | Other centers (n = 235,424) | |
|---|---|---|---|
WCRF/AICR lifestyle score, mean (SD) | 4.5 (1.1) | 4.5 (1.1) | 4.5 (1.1) |
Age at recruitment, mean (SD) | 51.7 (9.9) | 55.5 (7.2) | 51.3 (10.0) |
Highest level of attained education, % | |||
None/primary school | 30.4 | 31.1 | 30.3 |
Technical/secondary school | 41.7 | 52.1 | 40.6 |
University degree | 23.7 | 16.6 | 24.4 |
Unknown/missing | 4.2 | 0.2 | 4.7 |
Smoking status, % | |||
Never smokers | 59.1 | 45.1 | 60.6 |
Former smokers | 21.8 | 30.6 | 20.9 |
Current smokers | 17.5 | 24.3 | 16.8 |
Unknown/missing | 1.5 | 0.0 | 1.7 |
Chronic diseases at recruitment, % | |||
Yes | 3.3 | 4.5 | 3.2 |
Unknown | 6.8 | 0.4 | 7.5 |
Menopausal status, % | |||
Premenopausal | 33.4 | 17.6 | 35.0 |
Postmenopausal | 49.9 | 65.0 | 48.3 |
Perimenopausal | 16.8 | 17.5 | 16.7 |
Ever use of oral contraceptive pills, % | |||
Yes | 56.7 | 57.7 | 56.6 |
Unknown | 0.4 | 0.1 | 0.4 |
Ever use of menopausal hormone therapy, % | |||
Yes | 24.7 | 23.6 | 24.8 |
Unknown | 6.0 | 0.1 | 6.6 |
Age at menarche, % | |||
< 12 years | 15.7 | 15.6 | 15.7 |
≥ 12 to ≤ 15 years | 77.1 | 75.9 | 77.2 |
> 15 years | 6.2 | 7.2 | 6.1 |
Unknown | 1.0 | 1.3 | 1.0 |
Age at first full-term pregnancy, % | |||
Nulliparous | 15.6 | 13.9 | 15.8 |
< 21 years | 11.7 | 6.3 | 12.3 |
≥ 21 to ≤ 30 years | 63.9 | 69.1 | 63.4 |
> 30 years | 8.6 | 10.7 | 8.4 |
Unknown | 0.2 | 0.0 | 0.2 |