Table 1.

Age-standardized characteristics at baseline of the EPIC study and the NHS and NHSII

EPICaNHSaNHSIIa
Participants, n301,10768,06387,343
Means (SD)
 Age, yb49.8 (9.9)45.3 (7.2)35.9 (4.6)
 Age at menarche, y13.1 (1.5)12.4 (1.8)12.4 (1.4)
 Body mass index, kg/m224.9 (4.4)24.3 (4.5)24.5 (5.3)
 Total energy (kcal/day)1934 (541)1570 (501)1794 (548)
Percentages
 Parous849473
 Ever use oral contraceptives605083
 Postmenopausal44271
 Ever smoked435734
 Ever use postmenopausal hormones1881
  • aExposures at the study baseline (1980 in the NHS; 1991 in the NHSII).

  • bValues are not age-standardized.