Table 1.

Distribution of selected characteristics and risk factors in breast cancer cases and population controls

CategoryCases
Controls
Pa
n%n%
Age (yr)
    ≤408120.28922.10.77
    41–458721.69222.9
    46–5012831.812631.3
    >5010626.49523.6
    Mean (SD)45.7 (6.2)45.2 (6.5)0.2b
BMI (kg/m2)
    <18.582.661.6<0.01
    18.5–2517856.917445.0
    25–307223.012732.8
    >305517.68020.7
    Missing8915
    Mean (SD)25.6 (5.4)26.5 (5.6)0.04b
Education
    Up to high school12235.710927.10.07
    Technical school10731.315137.6
    Some college/university257.3358.7
    University degree8825.810726.6
    Missing600
Menopausal status
    Premenopausal22466.525667.40.80
    Postmenopausal11333.512432.6
    Uncertain721
    Missing581
Parity (no. of live births)
    Nulliparous7020.47017.40.50
    1 child5516.06115.2
    2 children14441.916641.3
    ≥3 children7521.810526.1
    Missing580
FH of breast and/or ovarian cancerc
    No31377.935788.8<0.01
    Yes8922.14511.2
FH of other cancersc
    No20250.224761.4<0.01
    Yes20049.815538.6
  • a χ2 test for homogeneity of proportions in contingency table.

  • b Student's t test (unequal variances).

  • c Only first-degree relatives.