Table 1 Description of the study population
Factor (number of individuals for whom information was available) | Incident breast cancer (n = 440) |
|---|---|
Age at baseline (years; 440) | 57.2 (7.1) |
Education (439) | 70 |
O-level college | 6 |
A-level college university | 24 |
Type of occupation (431) | |
Manual worker | 34 |
Nonmanual worker | 59 |
Employer/self-employed | 7 |
Married/cohabiting (440) | |
No | 34 |
Yes | 66 |
Age at menarche (years; 440) | |
≤12 | 22 |
>12 to <15 | 52 |
≥15 | 26 |
Parity (number of children; 426) | |
0 | 13 |
1 | 20 |
2 | 44 |
3 | 18 |
≥4 | 5 |
Age at first childbirth (years; 440) | |
Nullipara | 13 |
≤20 | 17 |
>20 to ≤25 | 34 |
>25 to ≤30 | 26 |
>30 | 10 |
Menopausal status (440) | |
Premenopausal | 25 |
Perimenopausal | 7 |
Postmenopausal | 68 |
Exposure to OC (439) | |
Never | 49 |
Ever | 51 |
Current use of HRT (440) | |
No | 71 |
Yes | 29 |
Body mass index (kg/m2; 440) | 25.5 (4.1) |
Alcohol consumption (440) | |
Nothing last year (teetotaller) | 11 |
Something last year (not last month) | 11 |
Something last month | 78 |
Smoking (440) | |
Never | 40 |
Current | 30 |
Ex | 30 |