Marly Augusto Cardoso|Luciana Yuki Tomita|Elaine Cristina Laguna
Assessing the validity of a food frequency questionnaire among low-income women in São Paulo, southeastern Brazil
Instituto de Saúde|Universidade de São Paulo|Instituto de Saúde|Universidade de São Paulo|Instituto de Saúde|Universidade de São Paulo
study describes validity food frequency questionnaire ffq 93 lowincome women 2065 years participating casecontrol study paulo brazil two ffq ffq1 ffq2 12 months apart three 24hour dietary recalls 24hr conducted 2003 2004 estimate dietary intake past year pearson correlation coefficients crude energyadjusted deattenuated used comparisons ffq 24hr agreement methods examined blandaltman analysis assessment longterm reliability energyadjusted intraclass correlation coefficients mostly around 040 higher vitamin folate 050056 energyadjusted attenuationcorrected pearson validity correlations ffq dr ranged 030054 macronutrients 020048 micronutrients higher value calcium 075 small proportions grossly misclassified nutrient intakes blandaltman plots indicated ffq accurate assessing nutrient intake group level