Table 1.

Selected risk factors for colorectal cancer in relation to number of ACF

nNo. of ACF (%)*
Age (y)
First-degree relative with a history of colorectal cancer
History of adenoma
    ≤65 y old
    >65 y old
Cigarette smoking
    ≤65 y old
        Not current922.233.344.40.12§
    >65 y old
        Not current140.035.764.3
NSAID use at least weekly during the past year
    ≤65 y old
    >65 y old
Frequency of NSAID use during the past year
    ≤65 y old
        0-6 times/wk837.525.037.50.96§
        ≥7 times/wk742.928.628.6
    >65 years old
        0-6 times/wk60.050.050.0
        ≥7 times/wk110.027.372.7
  • * Row percentages are presented in the columns below this header.

  • Unadjusted P from Fisher's exact test.

  • History of adenoma: one or more adenomas identified during the study colonoscopy or at a previous colonoscopy.

  • § Age-adjusted P from Cochran-Mantel-Haenszel test, with age categories of ≤65 and >65 years.

  • Includes aspirin.