Table 1

Age-standardizeda characteristics (%) of women with breast cancer and controls age 50–79 years, 1992–1994

CharacteristicCasesControls
Users (N = 1471)Nonusers (N = 3827)Users (N = 1439)Nonusers (N = 4132)
Age (yrs)
 50–5936234028
 60–6938403841
 70–7926372231
Age at menopause (yrs)b
 <4526183322
 45–5452604758
 ≥5510141013
 Unknown128107
Type of menopause
 Natural48744472
 Surgical50205422
 Premenopausal2626
Age at first full-term pregnancy (yrs)
 ≤1913121415
 20–2966666966
 ≥3091079
 Nulliparous12121010
Body mass index quartile (kg/m2)
 1 (13.2–22.6)26192724
 2 (22.7–25.3)26232924
 3 (25.4–29.0)24252425
 4 (29.1–56.7)24332027
Family history of breast cancer
 No79788686
 Yes21231414
Education
 No high school diploma12211420
 High school diploma45474548
 At least some college43324132
Screening mammography historyc
 Never1030823
 Less than annual33354045
 At least annual57355232
Benign breast disease
 No71787883
 Yes29222217
Recent alcohol intake (drinks/day)
 017251826
 <165586460
 ≥118171814
Recent recreational physical activity
 None23301727
 Occasional/moderate48434843
 Frequent/vigorous29273530
Age at menarche (yrs)
 <1220191917
 1227262426
 >1253555757
  • a Control frequencies were adjusted to the age distribution of cases.

  • b Among postmenopausal women only.

  • c For the 5-year time period before the reference age.