Table 1

Characteristics of female breast cancer case patients and their control patients

Case patientsControl patientsCrude OR (95% CI)*
n3051,153
Age (years)
    <405 (1.6)7 (0.6)
    40–4914 (4.6)57 (4.9)
    50–5940 (13.1)167 (14.5)
    60–6999 (32.5)359 (31.2)
    70–79113 (37.0)445 (38.6)
    ≥8034 (11.2)118 (10.2)
BMI (kg/m2)
    <2548 (15.7)174 (15.1)1.00 (referent)
    25–30100 (32.8)356 (30.9)1.01 (0.68–1.48)
    ≥30138 (45.3)526 (45.6)0.95 (0.65–1.38)
    Unknown19 (6.2)97 (8.4)0.69 (0.38–1.27)
Smoking status
    Nonsmoker190 (62.3)677 (58.7)1.00 (referent)
    Current32 (10.5)168 (14.6)0.71 (0.47–1.07)
    Past71 (23.3)245 (21.2)1.08 (0.78–1.48)
    Unknown12 (3.9)63 (5.5)0.66 (0.33–1.31)
Estrogen use
    Nonuser220 (72.1)902 (78.2)1.00 (referent)
    1–19 prescriptions49 (16.1)174 (15.1)1.18 (0.82–1.70)
    ≥20 prescriptions36 (11.8)77 (6.7)2.10 (1.34–3.28)
Diabetes history (years)
    <157 (18.7)216 (18.7)1.00 (referent)
    1–255 (18.0)194 (16.8)1.14 (0.74–1.76)
    ≥2193 (63.3)743 (64.5)1.07 (0.74–1.54)
A1C (%)
    <6.569 (22.6)239 (20.7)1.00 (referent)
    6.5–7.472 (23.6)275 (23.9)0.91 (0.62–1.33)
    7.5–8.962 (20.4)233 (20.2)0.92 (0.62–1.39)
    ≥951 (16.7)187 (16.2)0.89 (0.58–1.38)
    Unknown51 (16.7)219 (19.0)0.68 (0.42–1.10)
Renal failure10 (3.0)43 (3.7)0.78 (0.38–1.63)
Congestive heart failure15 (4.9)88 (7.6)0.65 (0.37–1.14)
Ischemic heart disease60 (19.7)218 (18.9)1.09 (0.78–1.52)
  • Data are n (%) unless otherwise indicated.

  • *Adjusted for age, sex, general practice, and calendar time by matching.