title: Development, validity and reproducibility of a food frequency questionnaire in pregnancy for the Universiti Sains Malaysia birth cohort study.
abstract: BACKGROUND
  This study aimed to develop and examine the validity and reproducibility of a semi-quantitative food frequency questionnaire (FFQ) among Malay pregnant women in Kelantan, Malaysia.
  
  
  METHODS
  A total of 177 Malay pregnant women participated in the validation study while 85 of them participated in the reproducibility study which was carried out in the antenatal clinic of Universiti Sains Malaysia Hospital. The newly developed FFQ was validated against two 24-hour dietary recalls (DR). The FFQ was repeated 20 to 28 days apart.
  
  
  RESULTS
  Results showed that the FFQ moderately over-estimated the nutrient and food intakes compared to the DR. Spearman correlation coefficients for nutrients ranged from 0.24 (fat) to 0.61 (calcium) and for foods, ranged from 0.13 (organ meats, onion and garlic) to 0.57 (malt drink). For nutrients, 72 to 85% of women were classified into the correct quartiles from the FFQ and the DR while for foods, 67 to 85% of women were classified correctly. Bland-Altman plot showed relatively good agreement between these two dietary methods. The intra-class correlation (ICC) was used to estimate reproducibility. It ranged from 0.75 (vitamin C) to 0.94 (phosphorus) for nutrients while it ranged from 0.73 (confectionary) to 0.96 (coffee) for foods.
  
  
  CONCLUSIONS
  On average, at least 90% of pregnant women were correctly classified into the quartiles for nutrients and foods from the two sets of the FFQ. The FFQ presented acceptable reproducibility and appears to be a valid tool for categorising pregnant women according to dietary intake.
authors.affiliation: Nutrition Programme, School of Health Sciences, Universiti Sains Malaysia, Health Campus, 16150 Kubang Kerian, Kelantan, Malaysia.
authors.forename: S L
authors.initials: SL
authors.lastname: Loy
authors.forename: M
authors.initials: M
authors.lastname: Marhazlina
authors.forename: Azwany Y
authors.initials: AY
authors.lastname: Nor
authors.forename: Jan J M
authors.initials: JJ
authors.lastname: Hamid
mesh_terms: D000328:Adult; D015331:Cohort Studies; D004034:Diet Surveys; D004435:Eating; D005260:Female; D006801:Humans; D008296:Malaysia; D008427:Maternal Health Services; D011247:Pregnancy; D011264:Pregnancy Trimesters; D015203:Reproducibility of Results; D011795:Surveys and Questionnaires / Q000592:standards*; D055815:Young Adult