Relative validity of an FFQ for pre-school children in the mother-child 'Rhea' birth cohort in Crete, Greece.

OBJECTIVE: To examine the relative validity of an FFQ based on parental report for pre-school children in the mother-child 'Rhea' birth cohort. DESIGN: The children's mothers completed an FFQ that referred to the children's dietary intake for the previous year by telephone interview. Mothers completed also three food records, two on weekdays and one on a weekend day. Spearman correlation coefficients were calculated for the energy-adjusted values. Weighted kappa statistics (κ(w)) and the Bland-Altman technique were used to test the degree of agreement between the two dietary methods. SETTING: Heraklion, Crete, Greece, 2011-2012. SUBJECTS: A total of ninety-nine mothers (corresponding to fifty-one boys and forty-eight girls) participated in the validation study. RESULTS: The mean and median values of all food group and nutrient intakes did not differ significantly between the two dietary methods. Overall, fair agreement was observed between the FFQ and the food records for ranking participants based on their intake, with κ(w) ranging from 0·21 to 0·40 for most foods and nutrients. On average, 88 % of participants were classified into the same or adjacent tertiles for nutrient and food group intakes by both dietary methods. The degree of agreement was also confirmed by the visual examination of the Bland-Altman plots. CONCLUSIONS: The study indicates that the Rhea 4 years FFQ is a relatively accurate tool for assessing habitual food group and nutrient intakes among pre-school children in Crete, Greece.