Reproducibility of a food frequency questionnaire for adolescents.
To assess the reproducibility of a validated 76-item food frequency questionnaire designed to estimate diet in adolescents (Adolescent Food Frequency Questionnaire--AFFQ) in the city of Sao Paulo, Brazil, a test-retest study was conducted (n = 49). Intraclass correlation coefficient (ICC), weighted kappa, and percentage of agreement were used in both crude and energy-adjusted nutrient intakes. Bland Altman plots were used to examine the limits of agreement for energy and macronutrients. The ICC ranged from 0.48 (carbohydrates) to 0.65 (vitamin C) in crude values and from 0.25 (total fat) to 0.58 (vitamin C) in adjusted values. Kappa values ranged from 0.28 (protein and fiber) to 0.56 (unsaturated fat). Bland Altman showed a trend towards larger difference in energy according to increased intake values and a bias towards extreme values for fat intake. The percent of individuals classified in the same category on the two occasions was on average 54.2%. By conclusion, the Adolescent Food Frequency Questionnaire showed reasonable reproducibility and can be used in studies that aim to classify groups into intake categories.
Marchioni
Dirce Maria Lobo
DM
Faculdade de Saúde Pública, Universidade de São Paulo, São Paulo, Brasil. bslater@usp.br
Voci
Silvia Maria
SM
Lima
Flávia Emília Leite de
FE
Fisberg
Regina Mara
RM
Slater
Betzabeth
B
D000293:Adolescent; D000294:Adolescent Behavior; D001938:Brazil; D004032:Diet; D015930:Diet Records; D002149:Energy Intake; D005247:Feeding Behavior; D005260:Female; D006801:Humans; D008297:Male; D015203:Reproducibility of Results; D011795:Surveys and Questionnaires / Q000592:standards*