Table 2

Associations between occupational and leisure-time physical activity and colon and rectal cancersa

No. of casesPerson-yearsbRRc (95% CI)P for trendd
Colon cancer
Occupational activity
 Nonworker79105,0340.61 (0.39–0.98)
 Sedentary2838,0101.0Reference
 Light2250,6620.60 (0.34–1.04)
 Moderate/Heavy2370,3610.45 (0.26–0.78)0.003
Leisure-time activity
 Sedentary69108,3871.0Reference
 Active83155,6260.82 (0.59–1.13)
Rectal cancer
Occupational activity
 Nonworker52104,9850.62 (0.34–1.11)
 Sedentary1837,9851.0Reference
 Light1750,6390.71 (0.36–1.37)
 Moderate/Heavy1770,3370.50 (0.26–0.97)0.04
Leisure-time activity
 Sedentary45108,3441.0
 Active60155,5460.93 (0.63–1.37)
  • a Relative risk (RR) and 95% confidence interval (CI).

  • b Total person-years for cases and noncases in category of activity.

  • c RR for colon cancer is adjusted for age, supplement group, BMI, and smoking (cigarettes/day). RR for rectal cancer is adjusted for age and supplement group.

  • d The tests for trend use the sedentary group as the reference category. Nonworkers are not included in the trend test in the occupational activity analysis.