Acessibilidade / Reportar erro

Assessing the validity of a food frequency questionnaire among low-income women in São Paulo, southeastern Brazil

Avaliação de validade de um questionário de freqüência alimentar em mulheres de baixa renda residentes em São Paulo, Brasil

This study describes the validity of a food frequency questionnaire (FFQ) in 93 low-income women (20-65 years), participating in a case-control study in São Paulo, Brazil. Two FFQ (FFQ1 and FFQ2, 12 months apart) and three 24-hour dietary recalls (24hR) were conducted between 2003 and 2004 to estimate dietary intake during the past year. The Pearson correlation coefficients (crude, energy-adjusted and de-attenuated) were used for comparisons between FFQ and 24hR. The agreement between the methods was further examined by the Bland-Altman analysis. For the assessment of long-term reliability, the energy-adjusted intra-class correlation coefficients were mostly around 0.40, but higher for vitamin A and folate (0.50-0.56). Energy-adjusted, attenuation-corrected Pearson validity correlations between FFQ and DR ranged from 0.30-0.54 for macronutrients to 0.20-0.48 for micronutrients, with higher value for calcium (0.75). There were small proportions of grossly misclassified nutrient intakes, while Bland-Altman plots indicated that the FFQ is accurate in assessing nutrient intake at a group level.

Food Consumption; Validation Studies; Questionnaires; Women


Escola Nacional de Saúde Pública Sergio Arouca, Fundação Oswaldo Cruz Rua Leopoldo Bulhões, 1480 , 21041-210 Rio de Janeiro RJ Brazil, Tel.:+55 21 2598-2511, Fax: +55 21 2598-2737 / +55 21 2598-2514 - Rio de Janeiro - RJ - Brazil
E-mail: cadernos@ensp.fiocruz.br