title: Relative validity of a semi-quantitative food frequency questionnaire versus 3 day weighed diet records in middle-aged inhabitants in Chaoshan area, China.
abstract: OBJECTIVE
  The purpose of the study was to validate a semi-quantitative food frequency questionnaire1 (SQFFQ) against 3 day weighted diet records (WDRs) for middle-aged inhabitants in the Chaoshan area, China.
  
  
  METHODS
  100 middle-age healthy residents.
  
  
  METHODS
  Validity was examined via descriptive statistics and Pearson's correlations.
  
  
  RESULTS
  Pearson's correlation coefficients (CCs) with energy-adjustment quantified by the SQFFQ and 3 day WDRs (minimum-median-maximum) ranged from 0.31(Vegetables)-0.35-0.53 (Cereals) for the selected foods, and 0.12 (retinol)-0.41-0.58 (phosphorous) for the selected nutrients. Favorably high agreement for intakes of foods/nutrients was achieved along with low disagreement.
  
  
  CONCLUSIONS
  A moderate level of relative validity was observed; this food frequency questionnaire is reliable and valid for dietary assessment with middle-aged inhabitants in the Chaoshan area, China.
authors.affiliation: Department of Preventive Medicine, Shantou Medical University, Guangdong Province, Shantou 515-041, China. kli@stu.edu.cn
authors.forename: Li
authors.initials: L
authors.lastname: Ke
authors.forename: Takezaki
authors.initials: T
authors.lastname: Toshiro
authors.forename: Song
authors.initials: S
authors.lastname: Fengyan
authors.forename: Yu
authors.initials: Y
authors.lastname: Ping
authors.forename: Deng
authors.initials: D
authors.lastname: Xiaoling
authors.forename: Tajima
authors.initials: T
authors.lastname: Kazuo
mesh_terms: D000328:Adult; D002681:China; D004034:Diet Surveys; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D015203:Reproducibility of Results; D011795:Surveys and Questionnaires; D013997:Time Factors