title: Relative validity of micronutrient and fiber intake assessed with two new interactive meal- and Web-based food frequency questionnaires.
abstract: BACKGROUND
  The meal- and Web-based food frequency questionnaires, Meal-Q and MiniMeal-Q, were developed for cost-efficient assessment of dietary intake in epidemiological studies.
  
  
  OBJECTIVE
  The objective of this study was to evaluate the relative validity of micronutrient and fiber intake assessed with Meal-Q and MiniMeal-Q. The reproducibility of Meal-Q was also evaluated.
  
  
  METHODS
  A total of 163 volunteer men and women aged between 20 and 63 years were recruited from Stockholm County, Sweden. Assessment of micronutrient and fiber intake with the 174-item Meal-Q was compared to a Web-based 7-day weighed food record (WFR). Two administered Meal-Q questionnaires were compared for reproducibility. The 126-item MiniMeal-Q, developed after the validation study, was evaluated in a simulated validation by using truncated Meal-Q data.
  
  
  RESULTS
  The study population consisted of approximately 80% women (129/163) with a mean age of 33 years (SD 12) who were highly educated (130/163, 80% with >12 years of education) on average. Cross-classification of quartiles with the WFR placed 69% to 90% in the same/adjacent quartile for Meal-Q and 67% to 89% for MiniMeal-Q. Bland-Altman plots with the WFR and the questionnaires showed large variances and a trend of increasing underestimation with increasing intakes. Deattenuated and energy-adjusted Spearman rank correlations between the questionnaires and the WFR were in the range ρ=.25-.69, excluding sodium that was not statistically significant. Cross-classifications of quartiles of the 2 Meal-Q administrations placed 86% to 97% in the same/adjacent quartile. Intraclass correlation coefficients for energy-adjusted intakes were in the range of .50-.76.
  
  
  CONCLUSIONS
  With the exception of sodium, this validation study demonstrates Meal-Q and MiniMeal-Q to be useful methods for ranking micronutrient and fiber intake in epidemiological studies with Web-based data collection.
authors.affiliation: Karolinska Institutet, Department of Medical Epidemiology and Biostatistics, Stockholm, Sweden. sara.christensen@ki.se.
authors.forename: Sara E
authors.initials: SE
authors.lastname: Christensen
authors.forename: Elisabeth
authors.initials: E
authors.lastname: Möller
authors.forename: Stephanie E
authors.initials: SE
authors.lastname: Bonn
authors.forename: Alexander
authors.initials: A
authors.lastname: Ploner
authors.forename: Olle
authors.initials: O
authors.lastname: Bälter
authors.forename: Lauren
authors.initials: L
authors.lastname: Lissner
authors.forename: Katarina
authors.initials: K
authors.lastname: Bälter
mesh_terms: D000328:Adult; D004034:Diet Surveys / Q000379:methods*; D004043:Dietary Fiber; D002149:Energy Intake; D005260:Female; D006801:Humans; D020407:Internet; D008297:Male; D062407:Meals; D018977:Micronutrients; D008875:Middle Aged; D015203:Reproducibility of Results; D011795:Surveys and Questionnaires; D013548:Sweden; D055815:Young Adult
chemical_list: D004043:Dietary Fiber; D018977:Micronutrients
keywords: FFQ; Internet; adult; micronutrients; reproducibility; validity; weighed food record