British Journal of Nutrition

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British Journal of Nutrition (2010), 103:1808-1816 Cambridge University Press
Copyright © The Authors 2010

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Dietary Surveys and Nutritional Epidemiology

Relative validity of a semi-quantitative food-frequency questionnaire in an elderly Mediterranean population of Spain

Joan D. Fernández-Ballarta1a2 c1, Josep Lluís Piñola3, Itziar Zazpea4, Dolores Corellaa2a5, Paula Carrascoa2a5, Estefanía Toledoa4, Manuel Perez-Bauera3, Miguel Ángel Martínez-Gonzáleza4, Jorge Salas-Salvadóa1a2 and José M. Martín-Morenoa6

a1 Preventive Medicine and Human Nutrition Units, Faculty of Medicine and Health Science, Universitat Rovira i Virgili, Spain
a2 CIBERobn CB06/03 Fisiopatologia de la Obesidad y Nutrición, Instituto de Salud Carlos III, Spain
a3 Àmbit d'Atenció Primaria Tarragona-Reus, Institut Català de la Salut, Spain
a4 Department of Preventive Medicine and Public Health, Medical School-Clínica Universitaria, University of Navarra, Pamplona, Spain
a5 Genetic and Molecular Epidemiology Unit, University of Valencia, Spain
a6 Department of Preventive Medicine and Public Health, Medical School, and Healthcare Quality Unit, University Clinical Hospital University of Valencia, Spain
Article author query
fernández-ballart jd [PubMed]  [Google Scholar]
piñol jl [PubMed]  [Google Scholar]
zazpe i [PubMed]  [Google Scholar]
corella d [PubMed]  [Google Scholar]
carrasco p [PubMed]  [Google Scholar]
toledo e [PubMed]  [Google Scholar]
perez-bauer m [PubMed]  [Google Scholar]
martínez-gonzález má [PubMed]  [Google Scholar]
salas-salvadó j [PubMed]  [Google Scholar]
martín-moreno jm [PubMed]  [Google Scholar]


The aim of the present study was to assess reproducibility and relative validity of a self-administered FFQ used in the PREDIMED Study, a clinical trial for primary prevention of CVD by Mediterranean diet in a population at high cardiovascular risk. The FFQ was administered twice (FFQ1 and FFQ2) to explore reproducibility at 1 year. Four 3 d dietary records (DR) were used as reference to explore validity; participants therefore recorded their food intake over 12 d in the course of 1 year. The degree of misclassification in the FFQ was also evaluated by a contingency table of quintiles comparing the information from the FFQ2 and the DR. A total of 158 men and women (aged 55–80 years) were asked not to modify their dietary habits during the study period. Reproducibility for food groups, energy and nutrient intake, explored by the Pearson correlation coefficient (r) ranged 0·50–0·82, and the intraclass correlation coefficient (ICC) ranged from 0·63 to 0·90. The FFQ2 tended to report higher energy and nutrient intake than the DR. The validity indices of the FFQ in relation to the DR for food groups and energy and nutrient intake ranged (r) from 0·24 to 0·72, while the range of the ICC was between 0·40 and 0·84. With regard to food groups, 68–83 % of individuals were in the same or adjacent quintile in both methods, a figure which decreased to 55–75 % for energy and nutrient intake. We concluded that FFQ measurements had good reproducibility and a relative validity similar to those of FFQ used in other prospective studies.

(Received July 03 2009)

(Revised November 30 2009)

(Accepted December 02 2009)

(Online publication January 27 2010)

Key Words:Validity; Reproducibility; FFQ; Dietary records; Mediterranean population; PREDIMED Study; Spain


c1 Corresponding author: Dr Joan D. Fernandez-Ballart, fax +34 977759322, email


Abbreviations: DR, dietary record; ICC, intraclass correlation coefficient