Table 2.
Distribution of selected characteristicsa of the study population (n = 68,160) at cohort enrolment according to smoking status
| Characteristics | Current smokers n = 22,077 | Former smokers n = 21,501 | Never smokers n = 24,582 | p-valueb |
|---|---|---|---|---|
| Age at enrolment (year) | 48.7 | 49.7 | 50.7 | <0.0001 |
| Age at diagnosis (year) | 59.5 | 60.5 | 61.9 | 0.0206 |
| Education (year) | 11.2 | 12.1 | 12.5 | <0.0001 |
| Post-menopausal at enrolment | 35.0 | 33.9 | 38.5 | <0.0001 |
| Age at menopause (year)c | 47.3 | 48.4 | 49.0 | <0.0001 |
| Ever HC use (%) | 62.3 | 59.2 | 47.0 | <0.0001 |
| Ever PM HT use (%) | 28.6 | 28.8 | 25.0 | <0.0001 |
| Mean PA scored | 5.4 | 5.5 | 5.5 | <0.0001 |
| Height (cm) | 166.1 | 166.3 | 166.0 | 0.1 |
| BMI at enrolmente | 23.9 | 24.8 | 24.7 | <0.0001 |
| Teetotallers (%) | 5.2 | 6.2 | 19.5 | <0.0001 |
| Alcohol consumption (g/day)f | 4.1 | 4.1 | 3.2 | <0.0001 |
Abbreviations: HC Hormonal contraceptive, PM Post-menopausal, HT Hormone therapy, PA Physical activity, BMI Body mass index
aGiven as mean unless otherwise specified
bT-test or chi-square test for differences between current and never smokers
cAmong women that were postmenopausal at enrolment
dMean recreational and work related physical activity score on a 10-level scale (1–10)
eBMI = the weight in kilograms divided by the square of the heights in meters)
fAmong drinkers