[Validity and reproducibility of an Internet-based questionnaire (Web-CAAFE) to evaluate the food consumption of students aged 7 to 15 years].

The study evaluated the validity and reproducibility of the food consumption section of the questionnaire Food Intake and Physical Activity of School Children (Web-CAAFE), an Internet-based software for the qualitative measurement of food consumption by recalling the previous day. A total of 390 students in grades 2 to 5 (7 to 15 years) of a semi-integral public school participated in the study. The validity was tested by comparing the report in the Web-CAAFE and the direct observation of food consumed in the school in the previous day. The reproducibility was evaluated in a sub-sample of 92 schoolchildren, by comparing repeated reports in the Web-CAAFE on the same day. Probabilities of accuracy in the Web-CAAFE report in relation to the observation (matches, omissions and intrusions and respective 95% confidence intervals) among seven food groups were estimated through multinomial logistic regression. The average for the match rate was 81.4% (variation: 62% sweets and 98% beans); for the omission rate was 16.2% (variation between 2.1% dairy products and 28.5% sweets); for the intrusion rate was 7.1% (variation between 1.3% beans and 13.8% cereals). Sweets, cereals and processed foods, snack foods and fried foods simultaneously exhibited higher rates of omission and intrusion. Students 10 years of age or older had lower probabilities of intruding food items. There were no significant variations in the accuracy of the report between repeated measures. The Web-CAAFE was a valid and reliable instrument for the evaluation of food consumption, when applied to students in grades 2 to 5 of public schools.