Table 2.

Age- and multivariate-adjusted HRs and 95% CIs by cigarette smoking characteristics among current and former smokers compared with never smokers (CPS-II Nutrition Cohort, 1992-2005)

AllMenWomen
CasesAge-adjusted HRMultivariate HR* (95% CI)CasesAge-adjusted HRMultivariate HR* (95% CI)CasesAge-adjusted HRMultivariate HR* (95% CI)
Never smokers8131.001.00 (reference)3031.001.00 (reference)5101.001.00 (reference)
Former smokers9931.341.23 (1.11-1.36)6191.351.26 (1.09-1.45)3741.151.19 (1.04-1.37)
Current smokers1561.571.27 (1.06-1.52)841.541.24 (0.96-1.59)721.471.30 (1.01-1.68)
Former smokers
Age at cessation
    Before age 402611.071.05 (0.91-1.22)1661.151.15 (0.95-1.39)950.850.92 (0.74-1.16)
    40-49 y of age2421.411.31 (1.13-1.52)1511.331.27 (1.04-1.55)911.321.40 (1.12-1.76)
    50-59 y of age2601.601.44 (1.24-1.66)1641.591.45 (1.19-1.77)961.411.43 (1.14-1.78)
    Age 60 or older1601.491.29 (1.08-1.54)951.481.29 (1.01-1.63)651.351.30 (1.00-1.70)
P trend = 0.0014P trend = 0.08P trend = 0.003
Years since cessation
    ≥31 y ago2391.031.03 (0.89-1.19)1471.061.07 (0.88-1.31)920.900.99 (0.79-1.25)
    21-30 y ago2381.371.28 (1.10-1.49)1601.431.36 (1.12-1.66)781.091.15 (0.90-1.46)
    11-20 y ago2321.481.33 (1.14-1.55)1391.421.30 (1.05-1.59)931.371.39 (1.11-1.75)
    1-10 y ago2141.721.48 (1.27-1.73)1301.701.48 (1.19-1.83)841.531.47 (1.16-1.86)
P trend = 0.0003P trend = 0.033P trend = 0.002
Current smokers
Duration of smoking
    <40 y291.191.02 (0.69-1.49)121.250.98 (0.54-1.80)171.141.04 (0.63-1.71)
    40-49 y711.681.32 (1.02-1.72)361.461.12 (0.77-1.64)351.751.56 (1.09-2.23)
    50+ y561.821.38 (1.04-1.84)361.851.43 (0.99-2.07)201.521.32 (0.83-2.09)
P trend = 0.052P trend = 0.24P trend = 0.16
  • *Multivariate models are adjusted for age, body mass index, education, family history of colorectal cancer, physical activity, race, aspirin use, alcohol use, vegetable consumption, fiber/whole grain consumption, red and processed meat consumption, and history of endoscopy.