Table 1

Baseline characteristics of WBF population (1304 participants) and those with complete adherence data by having had a colonoscopy prior to or within 90 days after the last count of unused cereal boxes (1208 participants)

Variable1304 participants1208 participants
Age (yrs), mean ± SD66.6 ± 8.866.6 ± 8.8
Body mass index (kg/m2), mean ± SD26.5 ± 4.326.5 ± 4.3
n (%)n (%)
Group
 Low-fiber584 (44.8)562 (46.5)
 High-fiber720 (55.2)646 (53.5)
Gender
 Female432 (33.1)393 (32.5)
 Male872 (66.9)815 (67.5)
Race
 White1251 (95.9)1157 (95.8)
 Other53 (4.1)51 (4.2)
Marital Status
 Married or cohabitating1088 (83.4)1005 (83.2)
 Single215 (16.5)202 (16.7)
Education
 Some or all high-school592 (45.4)548 (45.4)
 At least 1 year college710 (54.5)658 (54.5)
History of colorectal cancer in one parent or sibling
 Yes220 (16.9)209 (17.3)
 No1084 (83.1)999 (82.7)
History of cancer other than colorectal cancer at least 5 years prior to study entry
 Yes85 (6.5)72 (6.0)
 No829 (63.6)773 (64.0)
Years on study
 ≤1.047 (3.6)43 (3.6)
 1.1–2.0127 (9.7)104 (8.6)
 2.1–3.0258 (19.8)239 (19.8)
 >3.0872 (66.9)822 (68.1)
Polyp Characteristics
 History of adenomas prior to baseline colonoscopy
  Yes452 (34.7)419 (34.7)
  No701 (53.8)654 (54.1)
 Polyp Location
  Distal only710 (54.7)659 (54.8)
  Proximal only350 (27.0)322 (26.8)
  Proximal and distal238 (18.3)221 (18.4)
 Number of polyps
  One745 (57.3)693 (57.5)
  Two290 (22.3)261 (21.7)
  Three or more266 (20.5)251 (20.8)
 Maximum polyp size
  <0.5 cm400 (30.7)363 (30.1)
  0.60–1.00 cm546 (41.9)512 (42.4)
  >1.00 cm358 (27.5)333 (27.6)
Lifestyle Variables
 Exercise
  At least once a week636 (55.4)612 (55.4)
  Never512 (44.6)492 (44.6)
 Current smoker
  Yes178 (13.7)152 (12.6)
  No1126 (86.4)1056 (87.4)
 Ever smoker
  Yes683 (52.4)637 (52.7)
  No449 (34.4)424 (35.1)
 10-yr history of regular aspirin use
 Yes368 (28.2)345 (28.6)
 No936 (71.8)863 (71.4)
Dietary variables, mean ± SD
 Energy (kcal/day)1909.3 ± 666.01903.6 ± 663.7
 Protein (g/day)73.4 ± 26.273.4 ± 26.3
 Carbohydrate (g/day)233.8 ± 87.4233.5 ± 86.6
 Fat (g/day)72.9 ± 33.372.5 ± 33.3
 Dietary fiber (g/day)18.7 ± 8.218.8 ± 8.1
 Dietary calcium (mg/day)852.7 ± 377.7852.7 ± 379.0
 Total calcium (mg/day)975.3 ± 441.8977.2 ± 444.2
Alcohol (g/day)7.5 ± 15.37.4 ± 14.8
Dietary folate (μg/day)283.3 ± 120.5284.4 ± 120.6
Total folate (μg/day)441.4 ± 253.1443.4 ± 249.9
Red meat (g/day)62.5 ± 48.962.4 ± 49.4