Table 1.

Selected characteristics of breast cancer cases and control women, Shanghai, China

CharacteristicCases, n = 378 (%)Controls, n = 1,070 (%)
Age (y)
    35-3914 (3.7)13 (1.2)
    40-4499 (26.2)470 (43.9)
    45-5080 (21.2)219 (20.5)
    50-5956 (14.8)124 (11.6)
    >60
129 (34.1)
244 (22.8)
Cases, n = 378 (age-adjusted %)*Controls, n = 1,070 (%)
Education (years completed)
    Elementary school or less112 (20.2)211 (19.7)
    Middle school236 (72.5)827 (77.3)
    College30 (7.3)31 (2.9)
1° Family history of breast cancer16 (4.3)17 (1.6)
Body mass index (kg/m2)
    ≤2062 (16.7)204 (19.1)
    21-25220 (60.8)627 (58.6)
    ≥2696 (22.5)239 (22.3)
Spouse smoking: no. cigarettes/d
    Nonsmoker146 (35.6)380 (35.5)
    1-9 cigarettes56 (16.6)119 (11.1)
    10-19 cigarettes74 (21.1)213 (19.9)
    ≥20 cigarettes102 (26.8)358 (33.5)
Physical activity
    Light89 (24.7)195 (18.2)
    Moderate275 (71.8)804 (75.1)
    Heavy14 (3.5)71 (6.6)
  • NOTE: P value for age-adjusted model stratified by year of interview (1995-1996, 1997, 1998-1999, and 2000-2001), using conditional logistic regression.

  • * Indirect age-adjusted percentages based on age distribution of the controls.

  • P < 0.05.

  • P < 0.01.