Table 1. Characteristics of pooled studies.
| APPS26 | CPPS20 | AFT21 | PPT24 | WBF19 | NPS25 | VA23 | UDCA18 | |
|---|---|---|---|---|---|---|---|---|
| Intervention | Antioxidants | Calcium | Aspirin/folate | High fibre/low fat diet | Wheat bran fibre | Surveillance interval | None | Ursodiol |
| Recruitment period | 1984–1988 | 1991–1998 | 1994–1998 | 1991–1998 | 1990–1998 | 1980–1990 | 1994–1997 | 1995–1999 |
| # Enrolled/included | 864/837 | 930/913 | 1121/1086 | 2079/2024 | 1429/1304 | 1418/939 | 895*/871 | 1285/1193 |
| Colonoscopy schedule (years) | 1 and 4 | 1 and 4 | 3 | 1 and 4 | 1 and 3 OR 3 | 1 and 3 OR 3 | 2 and 5 OR 5 | 3 |
| % With 1+ colo in the study interval | 96.9 | 98.2 | 96.9 | 97.4 | 91.3 | 81.0 | 97.3 | 92.8 |
| Mean/median follow-up (years) | 3.9/4.1 | 3.9/4.0 | 3.1/3.1 | 4.2/4.3 | 3.5/3.2 | 2.8/3.1 | 4.3/4.9 | 3.5/3.2 |
| Follow-up time (person-years) | 3283.4 | 3564.2 | 3393.4 | 8554.1 | 4516.0 | 2642.3 | 3742.6 | 4139.9 |
Data were from AFT, APPS, CPPS, NPS, PPT, UDCA, VA and WBF studies.
*
There were 3121 participants in the VA Study; 895 had adenomas at baseline and were included in this pooled analysis.
AFT, Aspirin Folate Trial; APPS, Antioxidant Polyp Prevention Study; CPPS, Calcium Polyp Prevention Study; NPS, National Polyp Study; PPT, Polyp Prevention Trial; UDCA, Ursodoxycholic Acid Study; VA, Veterans Affairs Cooperative Study; WBF, Wheat Bran Fiber Study.