Validation of a self-administered FFQ in adults in Argentina, Chile and Uruguay

Objective: To assess the reproducibility and validity among adults in the Southern Cone of Latin America (Argentina, Chile and Uruguay) of a self-administered FFQ to be used in the CESCAS I Study, an ongoing observational prospective cohort study to detect and follow up CVD and their risk factors, as well as in other epidemiological studies. Design: Relative validity of the FFQ was evaluated by comparing nutrient and selected food group intakes with those from three 24 h recalls (24HR) administered over 6 months. The FFQ was administered at baseline (FFQ1) and again after 3 months (FFQ2). Setting: Primary-care centres in Argentina, Chile and Uruguay. Subjects: Adults (n 147) aged 21-74 years. Results: Reproducibility (FFQ1 v. FFQ2): the intra-class correlation coefficients for nutrients ranged from 0.52 (potassium) to 0.74 (fat). Validity (FFQ1 v. the average of three 24HR): the Pearson correlations for energy-adjusted nutrients ranged from 0.39 (thiamin and cholesterol) to 0.59 (carbohydrate). Joint classification: overall, 66% of participants in the lowest 24HR quintile were in the lowest one or two FFQ1 quintiles, and 62% of those in the highest 24HR quintile were in the highest one or two FFQ1 quintiles. On average, only 4% were misclassified into extreme quintiles. Conclusions: The FFQ version for the Southern Cone seems to present moderate to acceptable relative validity and reliability for its use in the CESCAS I Study to measure dietary exposure.