title: Reproducibility of a short food frequency questionnaire for Japanese general population.
abstract: BACKGROUND
  In epidemiologic field studies, a food frequency questionnaire (FFQ) is one of the most feasible tools to assess usual dietary habits. The purpose of this study is to evaluate the reproducibility of consumption of foods and nutrients assessed with a self-administered short FFQ in a Japanese general population.
  
  
  METHODS
  We have investigated 1-year interval reproducibility of a self-administered short FFQ, comprising 47 food items, and 8 frequency categories, among 1,918 subjects (844 males and 1,074 females) who participated in health check-up programs in Central Japan.
  
  
  RESULTS
  Intakes of energy and 24 nutrients along with 15 food groups estimated using the first questionnaire (FFQ1) were approximately equal to those using the second (FFQ2). Spearman's rank correlation coefficients (CCs) between intakes of nutrients quantified with FFQ1 and FFQ2 in males were distributed as 0.74 - 0.66- 0.55 (maximum - median - minimum), and intraclass CCs (ICCs) as 0.85 - 0.78 - 0.67. Among females, Spearman's rank CCs were distributed as 0.73 - 0.62 - 0.54, and ICCs as 0.84 - 0.77 - 0.69. Percentages of exact agreement, exact agreement plus agreement within adjacent categories and disagreement according to quintile categorization were 43%, 80%, and 1%, for males, and 42%, 79%, and 1% for females. Reproducibility figures were higher for the elderly than for young people in both sexes.
  
  
  CONCLUSIONS
  Our FFQ yielded substantially high reproducibility and it may be applicable for assessing consumption of foods/food groups and energy and selected nutrients for the middle-aged and elderly population in Japan.
authors.affiliation: Department of Food Science and Nutrition, Faculty of Human Life and Environmental Sciences, Nagoya Women's University, Nagoya, Japan. nimaeda@nagoya-wu.ac.jp
authors.forename: Nahomi
authors.initials: N
authors.lastname: Imaeda
authors.forename: Chiho
authors.initials: C
authors.lastname: Goto
authors.forename: Yuko
authors.initials: Y
authors.lastname: Tokudome
authors.forename: Kaoru
authors.initials: K
authors.lastname: Hirose
authors.forename: Kazuo
authors.initials: K
authors.lastname: Tajima
authors.forename: Shinkan
authors.initials: S
authors.lastname: Tokudome
mesh_terms: D000367:Age Factors; D004032:Diet / Q000706:statistics & numerical data*; D005260:Female; D005502:Food / Q000706:statistics & numerical data*; D006801:Humans; D007564:Japan; D008297:Male; D008875:Middle Aged; D009749:Nutrition Surveys; D015203:Reproducibility of Results; D012737:Sex Factors; D011795:Surveys and Questionnaires