Table 1B. Characteristics of included cohort studies on dietary flavonoids and risk of colorectal cancer.
| Study | Design | Location | Time period; (years) | Exposure Ascertainment | Outcome assessment | Total subjects | Colon cancer cases | Confounding variables adjusted |
|---|---|---|---|---|---|---|---|---|
| Nimptsch et al. 2015 | Cohort | America | 26 | Validated FFQ | Histological confirmed | 118842 | 2519 | 1,3,4,5,6,8,12,15, 16,17 |
| Simons et al. 2009 | Cohort | Netherlands | 13.3 | Validated FFQ | Cancer Registry | 120852 | 2485 | 1,3,4,5,6,8,15 |
| Yang et al. 2009 | Cohort | China | 6.4 | Validated FFQ | Medical record | 68412 | 321 | 1,3,5,8,9,11,15,16, 19,20,21 |
| Wang et al. 2009 | Cohort | America | 11.5 | Validated FFQ | Medical record | 38408 | 305 | 3,4,5,6,7,9,15,16, 20,21 |
| Butler et al. 2008 | Cohort | Singapore | 10 | Validated FFQ | Cancer registry | 61321 | 961 | 1,2,18,6,4,3,11, 5,15,10 |
| Akhter et al. 2008 | Cohort | Japan | 7.6 | Validated FFQ | Medical record | 83063 | 886 | 1,3, 4,5, 6,8,9,13, 16,18, 21 |
| Mursu et al. 2008 | Cohort | Finnish | 16.2 | Food records | Cancer registry | 2590 | 55 | 1,3,6,5,4,3,10,16,7 |
| Oba et al. 2007 | Cohort | Japan | 8 | FFQ | Histological confirmed | 30221 | 213 | 1,3,4,5,6,16,21 |
| Knekt et al. 2002 | Cohort | Finnish | 6 | FFQ | Cancer Registry | 9865 | 90 | 1,2,3,6,13,14 |
Abbreviation: FFQ, food frequency questionnaire
1 = age, 2 = sex, 3 = body mass index, 4 = alcohol, 5 = physical activity, 6 = smoke, 7 = fibre, 8 = meat intake, 9 = fruit/vegetable intake, 10 = total energy intake (kcal/day), 11 = education 12 = NSAID, 13 = study location, 14 = occupation, 15 = family history of colorectal cancer, 16 = dietary supplements (calcium, n-3 polyunsaturated fatty acids, manganum, riboflavin, vitamin C, vitamin E, folate), 17 = history of endoscopy, 18 = history of diabetes mellitus, 19 = household income, 20 = menopausal status, 21 = current use of female hormones.