title: A 7-item versus 31-item food frequency questionnaire for measuring fruit, juice, and vegetable intake among a predominantly African-American population.
abstract: OBJECTIVE
  This study sought to determine which of 2 fruit and vegetable food frequency questionnaires (FFQs) most closely approximated intake measured by the average of four 24-hour dietary recalls.
  
  
  METHODS
  Participants completed either a 31-item FFQ (n = 70) or 7-item FFQ (n = 76) on 2 occasions approximately 2 weeks apart. During the interval between FFQs1 participants provided four 24-hour dietary recalls via telephone interview.
  
  
  METHODS
  Participants were 146 persons with food preparation responsibilities in families of students in grades 3 through 5. Respondents were predominantly African-American women in Atlanta, Ga.
  
  
  METHODS
  Pearson correlation coefficients of log-transformed values estimated the reliability of each FFQ and compared FFQ estimates to reference values. The intraclass correlation coefficient evaluated consistency across 24-hour recalls.
  
  
  RESULTS
  The first FFQs overestimated intake approximately twofold. The 31-item FFQ estimates exceeded 7-item FFQ estimates by approximately 30% . Correlations with recall estimates were high for the 7-item FFQ and moderate to low for the 31-item FFQ. The second FFQ estimates were more highly correlated to reference values. From the first to the second administration, 7-item FFQ estimates dropped from 5.2 to 2.7 servings, and 31-item FFQ estimates dropped from 6.7 to 3.5 servings. Neither FFQ produced highly reliable estimates.
  
  
  CONCLUSIONS
  Mean total fruit and vegetable consumption was closer to reference estimates for the first 7-item FFQ and the second 31-item FFQ. The 7-item FFQ correlated more highly with reference estimates than did the 31-item FFQ. Therefore, we conclude that for African-American adults, a 1-time-administered FFQ using 7 broad food categories correlates more highly with reference values than a FFQ using 31 individual fruit and vegetable items.
authors.affiliation: Department of Behavioral Sciences, University of Texas M.D. Anderson Cancer Center, Houston, USA.
authors.forename: C L
authors.initials: CL
authors.lastname: Warneke
authors.forename: M
authors.initials: M
authors.lastname: Davis
authors.forename: C
authors.initials: C
authors.lastname: De Moor
authors.forename: T
authors.initials: T
authors.lastname: Baranowski
mesh_terms: D000328:Adult; D001741:Black or African American / Q000706:statistics & numerical data*; D001628:Beverages; D005260:Female; D005638:Fruit; D006801:Humans; D008297:Male; D011939:Mental Recall; D012016:Reference Values; D015203:Reproducibility of Results; D013223:Statistics as Topic; D011795:Surveys and Questionnaires / Q000592:standards*; D013997:Time Factors; D014675:Vegetables