Avaliação de reprodutibilidade e validade de um questionário de freqüência alimentar em adultos residentes em Porto Alegre, Rio Grande do Sul, Brasil

Abstract

O estudo avaliou a reprodutibilidade e a validade relativa de um questionário de freqüência alimentar (QFA) em 83 indivíduos adultos, do Sul do Brasil. Utilizou-se o coeficiente de correlação Intraclasse (ICC), classificação em quartos de ingestão pelo QFA e IR24h e índice Kappa ponderado. Os nutrientes foram log transformados e corrigidos para calorias. A atenuação nas correlações foi corrigida pela variabilidade intrapessoal. Para a reprodutibilidade, os valores das correlações variaram de 0,44 (IC95%: -0,19-0,76) a 0,83 (IC95%: 0,72-0,90) para carboidrato e vitamina C, respectivamente. No estudo de validade, os coeficientes deatenuados variaram de 0,23 (IC95%: -0,22-0,61) a 0,86 (IC95%: 0,21-1,16) para a vitamina A e lipídeos, no QFA1, e de 0,50 (IC95%: -016-0,91) a 0,95 (IC95%: 0,79-1,05) para vitamina A e energia, no QFA2. O índice Kappa ponderado apresentou valor mais baixo para o cálcio (0,10; IC95%: 0,00-0,26) e valores mais altos para vitamina C no QFA1 (0,38; IC95%: 0,23-0,53) e energia no QFA2 (0,38; IC95%: 0,24-0,52). Os resultados indicam reprodutibilidade satisfatória para todos os nutrientes, com exceção do carboidrato, e validade relativa razoável, especialmente para os macronutrientes e vitamina C.

Comparison of a short version of the Food Frequency Questionnaire with its long version - a cross-sectional analysis in the Brazilian Longitudinal Study of Adult Health (ELSA-Brasil)

“…Among the 76 food items included, 58 came from the regression models, 14 from the list of 50% frequency reported by the participants, two from the researchers' decision (regional items) and two because they represented consumption by over 50% of the participants in their region. To validate this questionnaire, only the subset of the reduced food list was used, similarly to the technique used by Block et al 21 As found by Molina et al, 11 Henn et al, 22 Zanolla et al, 23 Giacomello et al 24 and Lima et al, 25 the average energy and nutrient intake was higher than the benchmark. This overestimation may be explained by the characteristics of the instrument, such as the perception of the portion consumed, memory and frequency of use that are established.…”

Validation of a food frequency questionnaire to assess the consumption of carotenoids, fruits and vegetables among adolescents: the method of triads

“…This fact has been constituted as an important limitation, since the types of errors can be correlated, so they are not independent errors 39 . Another recent study conducted with schoolchildren presents validation results of a questionnaire on the day prior (QUADA-3) in relation to direct observation conducted by trained researchers, avoiding the same sources of errors.…”

Development and validation of a food frequency questionnaire (FFQ-Porto Alegre) for adolescent, adult and elderly populations from Southern Brazil

“…The FFQ development requires several decisions about food selection, the number of items to be investigated, and the method for measuring the portion sizes, if the FFQ is quantitative. Validation is usually performed using a food diary 6 or 24hR 7,8,9 as the reference method. In general, the validity is determined through correlation coefficients, comparing the average intake, obtained via the FFQ and the reference method, as well as the classification of individuals according to the nutrient intake distribution in both methods 10 .…”