Table 3.
Invasive Breast Cancers: Hazard Ratios and Relative Indices of Inequality by Education Among all Women and Among Nulliparous, Parous, Premenopausal and Postmenopausal EPIC Women After Adjustment for Reproductive History and all Risk Factors Together.
| Model adjusted for | RII | 95% CI | Primary | Vocational secondary | Other secondary | University or post- seconday vocational | |||
|---|---|---|---|---|---|---|---|---|---|
| HR | HR | 95% CI | HR | 95% CI | HR | 95% CI | |||
| All women | |||||||||
| Model 0: Stratified for age and centera | 1.22 | 1.09, 1.37 | 1 | 1.09 | 1.01, 1.18 | 1.12 | 1.02, 1.23 | 1.19 | 1.08, 1.31 |
| M0 + Parity | 1.18 | 1.05, 1.33 | 1 | 1.08 | 0.99, 1.17 | 1.10 | 1.00, 1.21 | 1.16 | 1.06, 1.27 |
| M0 + Age at first full term pregnancy | 1.10 | 0.98, 1.24 | 1 | 1.06 | 0.98, 1.15 | 1.07 | 0.97, 1.17 | 1.10 | 1.00, 1.21* |
| M0 + Reproductive historyb | 1.11 | 0.98, 1.25 | 1 | 1.06 | 0.98, 1.15 | 1.07 | 0.97, 1.18 | 1.10 | 1.00, 1.21 |
| M0 + All risk factorsc | 0.99 | 0.87, 1.12 | 1 | 1.01 | 0.93, 1.10 | 1.00 | 0.91, 1.11 | 1.01 | 0.91, 1.12 |
| Nulliparous women | |||||||||
| Model 0: Stratified for age and centera | 1.13 | 0.84, 1.52 | 1 | 1.15 | 0.92, 1.44 | 1.10 | 0.85, 1.42 | 1.10 | 0.86, 1.38 |
| M0 + All risk factorsd | 1.00 | 0.73, 1.37 | 1 | 1.10 | 0.87, 1.38 | 1.02 | 0.78, 1.33 | 1.00 | 0.78, 1.27 |
| Parous women | |||||||||
| Model 0: Stratified for age and centera | 1.22 | 1.07, 1.38 | 1 | 1.08 | 0.99, 1.18 | 1.12 | 1.01, 1.24 | 1.20 | 1.08, 1.33 |
| M0 + Parity | 1.20 | 1.06, 1.36 | 1 | 1.07 | 0.98, 1.17 | 1.11 | 1.00, 1.13 | 1.19 | 1.07, 1.32 |
| M0 + Age at first full term pregnancy | 1.11 | 0.97, 1.26 | 1 | 1.06 | 0.97, 1.15 | 1.07 | 0.96, 1.19 | 1.11 | 1.00, 1.24* |
| M0 + Reproductive history | 1.11 | 0.98, 1.27 | 1 | 1.06 | 0.97, 1.15 | 1.07 | 0.97, 1.19 | 1.12 | 1.01, 1.25 |
| M0 + All risk factorsc | 0.99 | 0.87, 1.14 | 1 | 1.01 | 0.92, 1.10 | 1.01 | 0.91, 1.12 | 1.03 | 0.92, 1.15 |
| Premenopausal women | |||||||||
| Model 0: Stratified for age and centera | 1.33 | 1.04, 1.69 | 1 | 1.09 | 0.90, 1.33 | 1.22 | 1.01, 1.49 | 1.24 | 1.02, 1.51 |
| M0 + Parity | 1.30 | 1.02, 1.66 | 1 | 1.08 | 0.89, 1.31 | 1.21 | 0.99, 1.47 | 1.22 | 1.00, 1.48 |
| M0 + Age at first full term pregnancy | 1.11 | 0.86, 1.44 | 1 | 1.04 | 0.86, 1.27 | 1.13 | 0.92, 1.38 | 1.09 | 0.89, 1.34 |
| M0 + Reproductive history | 1.14 | 0.88, 1.47 | 1 | 1.05 | 0.86, 1.28 | 1.14 | 0.93, 1.39 | 1.11 | 0.91, 1.36 |
| M0 + All risk factorse | 1.00 | 0.77, 1.30 | 1 | 1.01 | 0.83, 1.23 | 1.06 | 0.87, 1.30 | 1.01 | 0.81, 1.24 |
| Postmenopausal women | |||||||||
| Model 0: Stratified for age and centera | 1.21 | 1.03, 1.41 | 1 | 1.09 | 0.98, 1.20 | 1.08 | 0.94, 1.23 | 1.20 | 1.05, 1.37 |
| M0 + Parity | 1.17 | 1.00*, 1.37 | 1 | 1.07 | 0.97, 1.19 | 1.06 | 0.93, 1.21 | 1.17 | 1.02, 1.33 |
| M0 + Age at first full term pregnancy | 1.09 | 0.93, 1.29 | 1 | 1.05 | 0.95, 1.17 | 1.02 | 0.89, 1.17 | 1.11 | 0.97, 1.27 |
| M0 + Reproductive history | 1.10 | 0.93, 1.29 | 1 | 1.05 | 0.95, 1.17 | 1.02 | 0.89, 1.17 | 1.11 | 0.97, 1.27 |
| M0 + All risk factorsf | 0.95 | 0.80, 1.12 | 1 | 0.99 | 0.89, 1.10 | 0.94 | 0.82, 1.08 | 1.00 | 0.87, 1.15 |
CI confidence interval; HR hazard ratios; RII relative index of inequality;
1 included in the CI;
Model 0 controls for age at baseline (1-year age category) and center;
Reproductive history: variable combining parity and age at first full term pregnancy;
reproductive history, ever breast feeding, common risk factors g, ever use of hormonal replacement therapy, menopausal status&age at menopause combined;
common risk factors g, ever use of hormonal replacement therapy, menopausal status&age at menopause combined;
reproductive history, ever breast feeding, common risk factors g;
reproductive history, ever breast feeding, common risk factors g, ever use of hormonal replacement therapy, age at menopause;
Common risk factors: age at menarche, ever use of oral contraceptives, height, BMI, alcohol consumption, total physical activity.