Table 1.

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

nNo. of ACF (%)*
P
0-45-7≥8
Age (y)
    50-59933.322.244.40.06
    60-69933.344.422.2
    70-80140.028.671.4
First-degree relative with a history of colorectal cancer
    No2917.231.051.70.76
    Yes333.333.333.3
History of adenoma
    ≤65 y old
        No580.020.00.00.02§
        Yes1020.030.050.0
    >65 y old
        No40.050.050.0
        Yes130.030.869.2
Cigarette smoking
    ≤65 y old
        Not current922.233.344.40.12§
        Current666.716.716.7
    >65 y old
        Not current140.035.764.3
        Current30.033.366.7
NSAID use at least weekly during the past year
    ≤65 y old
        No650.016.733.30.24§
        Yes933.333.333.3
    >65 y old
        No30.0100.00.0
        Yes140.021.478.6
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.