Table 1

Characteristics of pooled studies

InterventionAntioxidantsCalciumAspirin/folateHigh fibre/low fat dietWheat bran fibreSurveillance intervalNoneUrsodiol
Recruitment period1984–19881991–19981994–19981991–19981990–19981980–19901994–19971995–1999
# Enrolled/included864/837930/9131121/10862079/20241429/13041418/939895*/8711285/1193
Colonoscopy schedule (years)1 and 41 and 431 and 41 and 3 OR 31 and 3 OR 32 and 5 OR 53
% With 1+ colo in the study interval96.998.296.997.491.381.097.392.8
Mean/median follow-up (years)3.9/4.13.9/4.03.1/3.14.2/4.33.5/3.22.8/3.14.3/4.93.5/3.2
Follow-up time (person-years)3283.43564.23393.48554.14516.02642.33742.64139.9
  • 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.