title: Relative validity and reliability of an FFQ in youth with type 1 diabetes.
abstract: OBJECTIVE
  To evaluate the relative validity and reliability of the SEARCH FFQ that was modified from the Block Kids Questionnaire.
  
  
  METHODS
  Study participants completed the eighty-five-item FFQ twice plus three 24 h dietary recalls within one month. We estimated correlations between frequencies obtained from participants with the true usual intake for food groups and nutrients, using a two-part model for episodically consumed foods and measurement error adjustment.
  
  
  METHODS
  The multi-centre SEARCH for Diabetes in Youth Nutrition Ancillary Study.
  
  
  METHODS
  A subgroup of 172 participants aged 10-24 years with type 1 diabetes.
  
  
  RESULTS
  The mean correlations, adjusted for measurement error, of food groups and nutrients between the FFQ and true usual intake were 0·41 and 0·38, respectively, with 57 % of food groups and 70 % of nutrients exhibiting correlations >0·35. Correlations were high for low-fat dairy (0·80), sugar-sweetened beverages (0·54), cholesterol (0·59) and saturated fat (0·51), while correlations were poor for high-fibre bread and cereal (0·16) and folate (0·11). Reliability of FFQ intake based on two FFQ administrations was also reasonable, with 54 % of Pearson correlation coefficients ≥0·5. Reliability was high for low-fat dairy (0·7), vegetables (0·6), carbohydrates, fibre, folate and vitamin C (all 0·5), but less than desirable for low-fat poultry and high-fibre bread, cereal, rice and pasta (0·2-0·3).
  
  
  CONCLUSIONS
  While there is some room for improvement, our findings suggest that the SEARCH FFQ performs quite well for the assessment of many nutrients and food groups in a sample of youth with type 1 diabetes.
authors.affiliation: 1Department of Epidemiology and Biostatistics and Center for Research in Nutrition and Health Disparities,Arnold School of Public Health,University of South Carolina,915 Greene Street,Columbia,SC 29208,USA.
authors.forename: Angela D
authors.initials: AD
authors.lastname: Liese
authors.affiliation: 2School of Nursing and Department of Biostatistics,University of North Carolina,Chapel Hill,NC,USA.
authors.forename: Jamie L
authors.initials: JL
authors.lastname: Crandell
authors.affiliation: 3Department of Biostatistical Sciences,Wake Forest School of Medicine,Winston-Salem,NC,USA.
authors.forename: Janet A
authors.initials: JA
authors.lastname: Tooze
authors.affiliation: 4Department of Nutrition and Department of Medicine,University of North Carolina,Chapel Hill,NC,USA.
authors.forename: Mary T
authors.initials: MT
authors.lastname: Fangman
authors.affiliation: 5Department of Nutritional Sciences,University of Cincinnati Medical Center,Cincinnati,OH,USA.
authors.forename: Sarah C
authors.initials: SC
authors.lastname: Couch
authors.affiliation: 1Department of Epidemiology and Biostatistics and Center for Research in Nutrition and Health Disparities,Arnold School of Public Health,University of South Carolina,915 Greene Street,Columbia,SC 29208,USA.
authors.forename: Anwar T
authors.initials: AT
authors.lastname: Merchant
authors.affiliation: 6Department of Epidemiology and Prevention,Wake Forest School of Medicine,Winston-Salem,NC,USA.
authors.forename: Ronny A
authors.initials: RA
authors.lastname: Bell
authors.affiliation: 4Department of Nutrition and Department of Medicine,University of North Carolina,Chapel Hill,NC,USA.
authors.forename: Elizabeth J
authors.initials: EJ
authors.lastname: Mayer-Davis
mesh_terms: D000293:Adolescent; D017195:Adolescent Nutritional Physiological Phenomena; D000328:Adult; D002648:Child; D002664:Child Nutritional Physiological Phenomena; D003922:Diabetes Mellitus, Type 1 / Q000178:diet therapy*; D003927:Diet, Diabetic; D018752:Diet, Fat-Restricted; D002149:Energy Intake; D006801:Humans; D007407:Interviews as Topic; D061212:Memory, Episodic; D015596:Nutrition Assessment; D010349:Patient Compliance; D015203:Reproducibility of Results; D013223:Statistics as Topic; D011795:Surveys and Questionnaires; D013689:Telephone; D014481:United States; D055815:Young Adult
keywords: Diabetes mellitus; FFQ validation; Reliability; Youth