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. 2014 Jul;17(7):1459-66.
doi: 10.1017/S1368980013001560. Epub 2013 Jun 20.

Relative validity and reproducibility of a quantitative FFQ for assessing nutrient intakes of vegetarians in Taiwan

Tina H T Chiu  1 , Hui-Ya Huang  2 , Kuan-Ju Chen  3 , Yu-R U Wu  2 , Jason P C Chiu  4 , Yi-Hwei Li  5 , Brian C-H Chiu  6 , Chin-Lon Lin  1 , Ming-Nan Lin  2
Affiliations

Relative validity and reproducibility of a quantitative FFQ for assessing nutrient intakes of vegetarians in Taiwan

Tina H T Chiu et al. Public Health Nutr. 2014 Jul.

Abstract

Objective: To assess the relative validity and reproducibility of the quantitative FFQ used in the Tzu Chi Health Study (TCHS).

Design: The reproducibility was evaluated by comparing the baseline FFQ with the 2-year follow-up FFQ. The validity was evaluated by comparing the baseline FFQ with 3 d dietary records and biomarkers (serum folate and vitamin B12). Median comparison, cross-classification and Spearman correlation with and without energy adjustment and deattenuation for day-to-day variation were assessed.

Setting: TCHS is a prospective cohort containing a high proportion of true vegetarians and part-time vegetarians (regularly consuming a vegetarian diet without completely avoiding meat).

Subject: Subsets of 103, seventy-eight and 1528 TCHS participants were included in the reproducibility, dietary record-validity and biomarker-validity studies, respectively.

Results: Correlations assessing the reproducibility for repeat administrations of the FFQ were in the range of 0·46-0·65 for macronutrients and 0·35-0·67 for micronutrients; the average same quartile agreement was 40%. The correlation between FFQ and biomarkers was 0·41 for both vitamin B12 and folate. Moderate to good correlations between the baseline FFQ and dietary records were found for energy, protein, carbohydrate, saturated and monounsaturated fat, fibre, vitamin C, vitamin A, K, Ca, Mg, P, Fe and Zn (average crude correlation: 0·47 (range: 0·37-0·66); average energy-adjusted correlation: 0·43 (range: 0·38-0·55); average energy-adjusted deattenuated correlation: 0·50 (range: 0·44-0·66)) with same quartile agreement rate of 39% (range: 35-45%), while misclassification to the extreme quartile was rare (average: 4% (range: 0-6%)).

Conclusions: The FFQ is a reliable and valid tool to rank relative intake of major nutrients for TCHS participants.

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References

    1. Willett W (2013) Food-frequency methods. In Nutritional Epidemiology, 3rd ed., pp. 70–95 [W Willett, editor]. New York: Oxford University Press.
    1. Kristal AR, Peters U & Potter JD (2005) Is it time to abandon the food frequency questionnaire? Cancer Epidemiol Biomarkers Prev 14, 2826–2828. - PubMed
    1. Smith AF (1991). Cognitive Processes in Long-Term Dietary Recall. Hyattsville, MD: US Department of Health and Human Services, Public Health Service, Centers for Disease Control, National Center for Health Statistics.
    1. Pisani P, Faggiano F, Krogh V et al. (1997) Relative validity and reproducibility of a food frequency dietary questionnaire for use in the Italian EPIC centres. Int J Epidemiol 26, Suppl. 1, S152–S160. - PubMed
    1. Crowe FL, Appleby PN, Travis RC et al. (2013) Risk of hospitalization or death from ischemic heart disease among British vegetarians and nonvegetarians: results from the EPIC-Oxford cohort study. Am J Clin Nutr 97, 597–603. - PubMed

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