title: A comprehensive FFQ developed for use in New Zealand adults: reliability and validity for nutrient intakes.
abstract: OBJECTIVE
  To evaluate the reliability and relative validity of a semi-quantitative FFQ for assessing the habitual intake of multiple nutrients in New Zealand (NZ) adults over the past 12 months.
  
  
  METHODS
  A 154-item FFQ was developed. After initial pre-testing, reliability was assessed using intra-class correlations. Relative validity was assessed by comparing nutrient intakes derived from the FFQ v. those from an 8 d diet record (8dWDR) collected over 12 months and selected blood biomarkers, using Spearman correlations. Supplementary cross-classification and Bland-Altman analyses were performed to assess validity of the FFQ v. the 8dWDR.
  
  
  METHODS
  Dunedin, NZ.
  
  
  METHODS
  One hundred and thirty-two males and females aged 30-59 years who completed all FFQ and 8dWDR and provided a blood sample.
  
  
  RESULTS
  Reliability coefficients ranged from 0·47 for Ca to 0·83 for alcohol, with most values falling between 0·60 and 0·80. The highest validity coefficients for energy-adjusted data were observed for alcohol (0·74), cholesterol (0·65) and β-carotene (0·58), and the lowest for Zn (0·24) and Ca (0·28). For all energy-adjusted nutrients mean percentage correct classification was 77·9% and gross misclassification was 4·5%. Results of Bland-Altman analyses showed wide limits of agreement for all micronutrients but high agreement was observed for most macronutrients (99% for protein, 103% for total fat). When compared with biomarkers, energy-adjusted coefficients were 0·34 for β-carotene and 0·33 for vitamin C.
  
  
  CONCLUSIONS
  The FFQ provides highly repeatable measurements and good validity in ranking individuals' intake, suggesting that it will be a useful tool to assess nutrient intake of NZ adults in future research.
authors.affiliation: Department of Human Nutrition, University of Otago, PO Box 56, Dunedin, New Zealand.
authors.forename: Cecilia H Y
authors.initials: CH
authors.lastname: Sam
authors.affiliation: Department of Human Nutrition, University of Otago, PO Box 56, Dunedin, New Zealand.
authors.forename: Sheila
authors.initials: S
authors.lastname: Skeaff
authors.affiliation: Department of Human Nutrition, University of Otago, PO Box 56, Dunedin, New Zealand.
authors.forename: Paula M L
authors.initials: PM
authors.lastname: Skidmore
mesh_terms: D000328:Adult; D001205:Ascorbic Acid / Q000097:blood; D015415:Biomarkers / Q000097:blood; D001835:Body Weight; D015930:Diet Records; D002149:Energy Intake; D005247:Feeding Behavior; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009520:New Zealand; D011446:Prospective Studies; D015203:Reproducibility of Results; D011795:Surveys and Questionnaires; D024502:alpha-Tocopherol / Q000097:blood; D019207:beta Carotene / Q000097:blood
chemical_list: D015415:Biomarkers; D019207:beta Carotene; D024502:alpha-Tocopherol; D001205:Ascorbic Acid