Table 1.
Characteristics of the 850 subjects in the AFPPS with at least one colonoscopy after the end of the randomized treatment*
| Characteristic | Placebo group (n = 285) | Low-dose aspirin group (n = 284) | High-dose aspirin group (n = 281) |
| Before randomization in AFPPS | |||
| Mean age, y (SD) | 57.5 (9.3) | 57.6 (9.1) | 57.7 (9.0) |
| Male subjects, No. (%) | 181 (64) | 189 (67) | 177 (63) |
| Race, No. (%) | |||
| White | 238 (84) | 252 (89) | 251 (89) |
| Black | 19 (7) | 15 (5) | 8 (3) |
| Hispanic | 19 (7) | 9 (3) | 13 (5) |
| Other | 9 (2) | 8 (3) | 9 (3) |
| Body mass index in kg/m2, No. (%) | |||
| <25 | 85 (30) | 88 (31) | 86 (31) |
| 25 to <30 | 140 (49) | 133 (47) | 134 (48) |
| ≥30 | 59 (21) | 62 (22) | 61 (22) |
| Alcohol user, No. (%) | 195 (73) | 181 (66) | 195 (71) |
| Cigarette smoking status, No. (%) | |||
| Never | 132 (46) | 128 (45) | 107 (38) |
| Former | 114 (40) | 115 (41) | 135 (48) |
| Current | 38 (13) | 40 (14) | 38 (14) |
| Positive first-degree family history of colorectal cancer, No. (%) | 79 (34) | 89 (37) | 102 (45) |
| Mean lifetime no. of adenomas (SD) | 2.4 (2.2) | 2.3 (1.9) | 2.6 (2.5) |
| During randomized aspirin treatment period | |||
| Randomized folate treatment assignment, No. (%) | 133 (51) | 137 (52) | 136 (53) |
| Mean time on randomized aspirin treatment, mo (SD) | 32.7 (3.7) | 32.3 (2.9) | 32.6 (3.4) |
| Frequency of nonprotocol NSAID use during the randomized period in days per month, No. (%) | |||
| 0 | 208 (73) | 218 (77) | 213 (76) |
| 1–4 | 53 (19) | 42 (15) | 49 (17) |
| >4 | 24 (8) | 24 (8) | 19 (7) |
| Subjects with adenomas at treatment completion, No. (%) | 143 (50) | 118 (42) | 138 (49) |
| During posttreatment observational follow-up period | |||
| Colonoscopies, No. (%) | |||
| 1 | 253 (89) | 260 (92) | 251 (89) |
| 2 | 28 (10) | 20 (7) | 23 (8) |
| ≥3 | 4 (1) | 4 (1) | 7 (3) |
| Subjects whose first posttreatment colonoscopy reached the cecum, No. (%) | 273 (96) | 267 (94) | 271 (96) |
| Mean time from the end of treatment to first colonoscopy, mo (SD) | 44.9 (14.1) | 47.7 (14.7) | 44.8 (14.4) |
| Median no. of questionnaires completed up to the first posttreatment colonoscopy (IQR) | 9 (4–11) | 9 (4–13) | 9 (4–10) |
| Frequency of NSAIDs use before the first colonoscopy in days per week†, No. (%) | |||
| <2 | 203 (73) | 194 (70) | 192 (69) |
| 2–4 | 32 (12) | 28 (10) | 36 (13) |
| ≥4 | 43 (15) | 56 (20) | 49 (18) |
*
AFPPS = Aspirin/Folate Polyp Prevention Study; low-dose aspirin = 81 mg; high-dose aspirin = 825 mg; NSAID = nonsteriodal anti-inflammatory drug; IQR = interquartile range.
†
Seventeen subjects did not complete any questionnaire from the end of aspirin treatment to the first posttreatment colonoscopy.