[Assessment of reproducibility and validity of a food frequency questionnaire in a sample of adults living in Porto Alegre, Rio Grande do Sul State, Brazil].
The reproducibility and validity of a Food Frequency Questionnaire (FFQ) was evaluated in 83 adults living in a State capital in southern Brazil. The reproducibility and validity were tested with intra-class correlation coefficients (ICC). Mean nutrient intakes from three 24-hour dietary recalls (24hDR) were compared to mean intakes from each FFQ (FFQ1 and FFQ2), adjusted for energy intake and within-person variation. Nutrients were categorized into quartiles and assessed using weighted kappa statistics. Mean ICC for the test-retest FFQ ranged from 0.44 (95%CI: -0.19-0.76) to 0.83 (95%CI: 0.72-0.90) for energy-adjusted carbohydrate and vitamin C intakes, respectively. Mean ICC, energy-adjusted and corrected for within-person variability, ranged from 0.23 (95%CI: -0.22-0.61) to 0.86 (95%CI: 0.21-1.16) for vitamin A and lipids for the FFQ1, and 0.50 (95%CI: -0.16-0.91) to 0.95 (95%CI: 0.79-1.05) for vitamin A and energy for the FFQ2. For the FFQ1, calcium showed the lowest weighted kappa value (0.10; 95%CI: 0.00-0.26), while vitamin C (0.38; 95%CI: 0.23-0.53) and total energy (0.38; 95%CI: 0.24-0.52) had the highest weighted kappa for the FFQ2. The FFQ showed good reproducibility and reasonable relative validity.
Zanolla
Anelise Fernanda
AF
Universidade do Vale do Rio dos Sinos, São Leopoldo, Brasil.
Olinto
Maria Teresa Anselmo
MT
Henn
Ruth Liane
RL
Wahrlich
Vivian
V
Anjos
Luiz Antonio dos
LA
D000328:Adult; D001938:Brazil; D004034:Diet Surveys; D002149:Energy Intake; D005247:Feeding Behavior; D005260:Female; D005502:Food / Q000706:statistics & numerical data*; D006801:Humans; D008297:Male; D008875:Middle Aged; D015203:Reproducibility of Results; D011795:Surveys and Questionnaires; D055815:Young Adult