Table 1.

Selected characteristics of the study populationa

CharacteristicsTotalNo. of adenomaAdenoma recurrencePb
Subjects, n (%)792 (100)422 (53.3)370 (46.7)
Age at enrollment, y, mean ± SD57.83 ± 9.5356.4 ± 9.559.4 ± 9.3<0.001
Sex, n (%)
 Male507 (64.0)250 (59.2)257 (69.5)0.003
 Female285 (36.0)172 (40.8)113 (30.5)
Family history of colorectal cancer,c n (%)
 No397 (60.9)218 (61.8)179 (59.9)0.24
 Yes255 (39.1)135 (38.2)120 (40.1)
Follow-up time,d mo, mean ± SD32.8 ± 3.632.6 ± 3.133.0 ± 4.10.14
Aspirin treatment group, n (%)
 Placebo253 (31.9)128 (30.3)125 (33.8)
 81-mg aspirin271 (34.2)161 (38.2)110 (29.7)0.04
 325-mg aspirin268 (33.8)133 (31.5)135 (36.5)0.83
Folate treatment group, n (%)
 Placebo358 (45.2)196 (46.5)162 (43.8)
 1-mg folate367 (46.3)192 (45.5)175 (47.3)0.51
 Not randomized to folate67 (8.5)34 (8.1)33 (8.9)0.55
  • aOnly participants self-identifying as “white, not of Hispanic origin” were included.

  • bTests for comparison between group with no adenoma and group with adenoma recurrence using 2-sample t test for continuous variables and Pearson χ2 test for categorical variables.

  • cFamily history data are missing for 140 subjects.

  • dMonths between randomization and follow-up colonoscopy.