Table 3.

Crude and multivariate-adjusted HRs of breast cancer in 218,169 women according to type of physical activity, stratified by menopausal status; the EPIC study

Type of physical activityPremenopausal women (n = 90,060)
Postmenopausal women (n = 128,109)
Cases*HR (95% CI)HR (95% CI)Cases*HR (95% CI)HR (95% CI)
Total activity index§
    Inactive1711.0 (1.0)1.03821.0
    Moderately inactive3311.02 (0.85-1.23)1.02 (0.84-1.24)1,0580.87 (0.77-0.98)0.89 (0.79-1.00)
    Moderately active2450.82 (0.66-0.99)0.84 (0.68-1.04)8850.80 (0.71-0.91)0.84 (0.74-0.96)
    Active730.98 (0.72-1.25)1.02 (0.77-1.36)1510.87 (0.71-1.05)0.92 (0.76-1.12)
    Ptrend0.1870.2670.0070.06
Occupational activity
    Sedentary2741.01.04951.01.0
    Standing3221.01 (0.84-1.20)1.02 (0.86-1.22)5140.91 (0.79-1.03)0.92 (0.81-1.05)
    Manual and heavy manual630.98 (0.74-1.31)1.04 (0.78-1.38)2161.05 (0.89-1.24)1.08 (0.91-1.29)
    Ptrend0.9540.7710.9420.743
Combined recreational and household activities (MET-h/wk)
    <552591.01.07881.01.0
    55-852090.91 (0.76-1.10)0.92 (0.76-1.10)7030.94 (0.84-1.04)0.94 (0.85-1.05)
    86-1262020.89 (0.73-1.09)0.91 (0.74-1.11)5660.84 (0.75-0.94)0.86 (0.76-0.96)
    >1261860.80 (0.64-0.99)0.82 (0.66-1.03)4900.81 (0.71-0.92)0.83 (0.73-0.95)
    Ptrend0.0470.1070.00030.002
Recreational activity (MET-h/wk)
    <142261.01.06521.01.0
    14-242260.91 (0.76-1.10)0.91 (0.75-1.10)6921.06 (0.95-1.18)1.05 (0.94-1.17)
    25-422180.96 (0.79-1.15)0.95 (0.78-1.14)6240.93 (0.84-1.04)0.92 (0.83-1.03)
    >421860.95 (0.77-1.16)0.94 (0.76-1.15)5790.95 (0.85-1.07)0.96 (0.85-1.08)
    Ptrend0.6660.5800.1570.176
Household activity (MET-h/wk)
    <282521.01.07671.01.0
    28-522330.92 (0.76-1.10)0.92 (0.77-1.11)7090.92 (0.83-1.02)0.94 (0.85-1.04)
    53-901940.80 (0.65-0.97)0.80 (0.65-0.99)6130.84 (0.75-0.95)0.86 (0.76-0.96)
    >901770.68 (0.54-0.86)0.71 (0.55-0.90)4580.78 (0.68-0.89)0.81 (0.70-0.93)
    Ptrend0.00070.0030.00010.001
  • * Numbers of cases do not always add up to total number of cases across each physical activity variable due to some missing values.

  • Crude relative risks: stratified by age at recruitment and study center (Cox model using age as underlying time variable).

  • Multivariate relative risks: based on crude model and additionally adjusted for educational attainment, smoking status, alcohol consumption, BMI, age at menarche, age at first pregnancy, current oral contraceptive use (premenopausal), and current HRT use (postmenopausal).

  • § Combined total physical activity index that is categorized into four activity levels based on a cross-tabulation of occupational activity by the combined household and recreational activities.

  • Categorical variable based on type of physical activity at work; nonworking category and missing values were excluded; manual and heavy manual categories were collapsed into one category due to low number of subjects; total premenopausal cases n = 659, postmenopausal cases n = 1,225.

  • Quartile cut points were obtained from the combined premenopausal and postmenopausal analytic cohort.