Validity and Reproducibility of a Precoded Questionnaire to Assess Fruit and Vegetable Intake in European 11- to 12-Year-Old Schoolchildren

• Published in: Annals of Nutrition and Metabolism
• Main Authors: Haraldsdóttir, Jóhanna, Thórsdóttir, Inga, de Almeida, Maria Daniel Vaz, Maes, Lea, Pérez Rodrigo, Carmen, Elmadfa, Ibrahim, Frost Andersen, Lene
• Format: Article in Journal/Newspaper
• Language: English
• Published: S. Karger AG 2005
• Subjects: Norway; Iceland
• Online Access: https://doi.org/10.1159/000087276; https://www.karger.com/Article/Pdf/87276

Background/Aims: Validity and reproducibility were evaluated of a new questionnaire to assess fruit and vegetable intakes in 11- to 12-year-old children. Methods: The precoded teacher-assisted self-administered questionnaire included two sections: a 24-hour recall part and a food frequency part. Validity was tested in 4 countries (Denmark, Iceland, Norway, Portugal; n = 43–60 per country) using a 1-day weighed food record and 7-day food records as reference methods. Test-retest (7–12 days apart) reproducibility was assessed in 6 countries (Belgium, Denmark, Iceland, Norway, Portugal, Spain; n = 60–74 per country). Results: Spearman rank correlations for fruit and vegetable intake according to the frequency part and the 7-day food record ranged between r = 0.40–0.53. Between 25–50% were classified into the same quartile and 70–88% into the same or adjacent quartile. Test-retest Spearman rank correlations for the food frequency part were r = 0.47–0.84. Three countries showed no significant difference between fruit intake as assessed with the 24-hour recall part and the 1-day weighed food record, and 2 countries showed no significant difference for vegetables. In the other countries, the 24-hour recall part resulted in substantially higher mean intake levels. Conclusion: Validity and reproducibility as to ranking of subjects were regarded to be satisfactory in all countries. Group mean intake, based on the original 24-hour part, was valid for fruit in 3 countries and for vegetables in 2 countries, and this part was subsequently adjusted to avoid overestimation, before the questionnaire was used in the Pro Children study.