Table 1.

Age-standardized characteristics of ever and never OC users among 88,691 NHSI participants at the midpoint of follow-up (1994) between 1980 and 2010 and 93,080 NHSII participants at the midpoint of follow-up (2001) between 1991 and 2010 [means (SD) or %]

NHSINHSII
Never-usersEver-usersNever-usersEver-users
(N = 45,237)(N = 43,454)(N = 12,957)(N = 80,123)
Age, years63.4 (6.5)57.5 (6.4)47.1 (4.5)46.8 (4.7)
Height, inches64.4 (2.4)64.6 (2.4)64.8 (2.7)64.9 (2.6)
Physical activity, MET-hours/week18.5 (22.5)18.6 (22.7)18.5 (23.0)18.9 (23.7)
Smoking, pack-years12.8 (19.7)12.6 (18.6)3.3 (8.0)5.1 (9.6)
Processed or red meat, servings/day0.4 (0.3)0.4 (0.3)0.7 (0.5)0.7 (0.5)
Folate, mcg/day443 (210)443 (214)612 (254)606 (255)
Calcium, mcg/day1,038 (473)1,054 (483)1,222 (510)1,223 (529)
BMIa, kg/m2
 <18.5551715
 18.5–22.918212425
 23–24.917181315
 25–29.931302224
 30+20192321
Aspirin use, times/weeka
 0–369709695
 4–615154b5b
 7–1088
 11+88
Alcohol, g/daya
 <561586460
 5–9.98979
 10–14.96746
 15+6835
Age at first birth, yearsa,c
 <2434392729
 24–2529282020
 26–2927243334
 30+1191917
Paritya
 0743730
 1761519
 225302834
 3+59582017
HT usea
 Premenopausal20221714
 Never31215345
 Past19151520
 Current31411521
Endoscopy screening, last two years21201010
  • aMay not add to 100% due to missing data.

  • bHighest categories were combined in NHSII due to sparse data.

  • cDistribution among parous women.