Measurement of fruit and vegetable consumption with diet questionnaires and implications for analyses and interpretation.

TitleMeasurement of fruit and vegetable consumption with diet questionnaires and implications for analyses and interpretation.
Publication TypeJournal Article
Year of Publication2005
AuthorsMichels, KB, Welch, AA, Luben, R, Bingham, SA, Day, NE
JournalAm J Epidemiol
Volume161
Issue10
Pagination987-94
Date Published2005 May 15
ISSN0002-9262
KeywordsAged, Ascorbic Acid, Biological Markers, Diet Surveys, Epidemiologic Research Design, Female, Food Habits, Fruit, Great Britain, Humans, Linear Models, Male, Middle Aged, Prospective Studies, Questionnaires, Vegetables
Abstract

Measurement error can have an important impact on the estimation of the true relation between diet and disease. The authors examined the performance of models regressing plasma vitamin C level on fruit and vegetable consumption and the effect of categorization of fruit and vegetable consumption on the association with plasma vitamin C. They used diet information reported by 4,487 participants in the Norfolk, United Kingdom, portion of the European Prospective Investigation into Cancer and Nutrition by means of a 7-day diet diary and a food frequency questionnaire (FFQ) (1993-1998). The authors found substantial differences in mean fruit and vegetable consumption assessed by the two diet instruments. Consumption estimated with the FFQ was about twice as high as that obtained with the 7-day diary, and the ranking of individuals according to estimates of fruit and vegetable consumption from the 7-day diary and the FFQ differed substantially. When fruit and vegetable consumption were categorized into quintiles, the two questionnaires produced similar associations of relative intake with plasma vitamin C, but estimation of the association of absolute intake with plasma vitamin C differed.

DOI10.1093/aje/kwi115
Alternate JournalAm. J. Epidemiol.
Citation Key10.1093/aje/kwi115
PubMed ID15870164
PubMed Central IDPMC1909917
Grant ListF06 TW005568 / TW / FIC NIH HHS / United States
F06 TW005568-01 / TW / FIC NIH HHS / United States
F06 TW05568 / TW / FIC NIH HHS / United States
R01 DK 54900 / DK / NIDDK NIH HHS / United States
R01 DK054900 / DK / NIDDK NIH HHS / United States
R01 DK054900-02 / DK / NIDDK NIH HHS / United States
/ / Wellcome Trust / United Kingdom