Table 1.

Characteristics (%) of IWHS participants across allergy categories

No (n = 14,527)Yes (n = 6,765)
Mean age in 1997, y (SE)72.1 (0.03)72.0 (0.05)
Mean age at diagnosis of colon cancer, y (SE)77.7 (0.28)77.0 (0.43)
Mean age at diagnosis of rectal cancer, y (SE)75.7 (0.7)78.2 (1.45)
BMI in 1997 (≥30 kg/m2)22.526.5
Waist-to-hip ratio, ≥0.8606 (highest tertile)32.634.9
Education (more than high school)41.146.3
Ever smoked29.435.4
≥40 pack-years of smoking5.98.1
Regular physical activity (yes)42.942.1
Energy intake (≥1,722.8 cal/d*)48.653.1
Calcium (≥1,046.3 mg/d*)48.952.8
Red meat (≥5 servings/wk*)56.856.3
Vitamin E (≥9.8 mg/d*)48.253.2
Multivitamins (yes)31.737.2
Alcohol intake (ever)47.048.1
Diabetes mellitus before 19979.310.8
HRT use before 199744.353.9
Aspirin use (ever)73.670.8
Nonaspirin NSAID use (ever)37.944.3
Family history of colon cancer5.05.3
  • Abbreviation: NSAID, nonsteroidal anti-inflammatory drug.

  • * Cut point is the cohort median. Calcium, red meat, and vitamin E were adjusted for total energy intake.

  • Information about these characteristics was obtained in 1986.

  • Analyses limited to the responders to the 1992 and 1997 surveys.