Table 1A. Characteristics of included case-control studies on dietary flavonoids and risk of colorectal cancer.
| Study | Design | Location/ Setting | Exposure Ascertainment | Outcome assessment | Total subjects | Colon cancer cases | Confounding variables adjusted |
|---|---|---|---|---|---|---|---|
| Shin et al. 2015 | Case-control hospital-based | Korea | Validated FFQ | Medical record | 3570 | 901 | 1,4,5,7 |
| Zamora-Ros et al. 2013 | Case-control hospital-based | Spanish | Validated FFQ | Histological confirmed | 825 | 424 | 1,2,4,5,6,7,8,10,12,15 |
| Budhathoki et al. 2011 | Case-control population-based | Japan | Computer-assisted interview | Histological confirmed | 1631 | 816 | 1,2,3,4,5,13,14,15,16 |
| Rossi et al. 2010 | Case-control hospital-based | Italy | Validated FFQ | Histological confirmed | 6107 | 1953 | 1,2,3,4,5,10,11,13,15 |
| Ward et al. 2010 | Prospective case-control | Norfolk | Diet diaries | Cancer Registry | 1103 | 220 | 1,3,5,6,7,8,10,12,15,16 |
| Kyle et al. 2009 | Case-control population-based | Britain | Validated FFQ | Histological confirmed | 672 | 264 | 1,10,12,15,16 |
| Theodoratou et al. 2007 | Case-control population-based | Britain | Validated FFQ | Histological confirmed | 2912 | 1456 | 3,4,5,6,7,9,10,12,15 |
| Cotterchio et al. 2006 | Case-control population-based | America | FFQ | Histological confirmed | 2985 | 1095 | 1,2,10 |
| Rossi et al. 2006 | Case-control hospital-based | Italy | Validated FFQ | Histological confirmed | 6107 | 1953 | 1,2,3,5,6,10,13,15 |
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).