Table 1

Characteristics of cases and controls

Cases (n = 315)Controls
Hospital (n = 219)Population (n = 307)
Age53 ± 9a51 ± 1153 ± 10
Age at menarche13 ± 513 ± 213 ± 2
No. of fertile years32 ± 729 ± 731 ± 7
Age at first birthb25 ± 424 ± 525 ± 4
No. of deliveries2.2 ± 22.4 ± 22.2 ± 2
BMI (kg/m2)25 ± 426 ± 524 ± 4
Breast fed >6 mob11%8%11%
Ever use of hormonal contraceptives68%65%62%
Ever use of hormonal replacement therapy42%35%36%
History of breast cancer in first-degree relativesc22%16%12%
History of benign breast diseased35%20%17%
  • a Mean ± SD.

  • b Among parous women only.

  • c Data for this variable were available for 310 cases, 214 hospital controls, and 304 population controls.

  • d Cyst puncture or benign breast illness investigated with surgery.