title: [Relative validity of food frequency questionnaire for estimating dietary iron intake of students with anemia].
abstract: OBJECTIVE
  To assess the relative validity of food frequency questionnaire (FFQ) for estimating dietary iron and its related nutrients and food intakes of students with anemia.
  
  
  METHODS
  FFQ and weighed dietary records combining with 24h dietary recalls (adopted as reference method) were applied respectively to investigate the diet of 156 anemic students aged 10 - 12 years. The average dietary intakes of iron, haem iron, non-haem iron, vitamin C, meat/fish/poultry and eggs were estimated. Wilcoxon matched-pairs signed-rank test, Spearman's rank correlation, cross-classification and actual values for surrogate categories were performed to assess the relative validity of FFQ.
  
  
  RESULTS
  Compared with the reference method, dietary iron and its related nutrients and food intakes were overestimated by FFQ, and bear poor correlation with reference method. The results of cross-classification and actual values for surrogate categories indicated that the low and high intakes of all dietary components could not be clearly differentiated by FFQ.
  
  
  CONCLUSIONS
  FFQ presents unsatisfactory accuracy in assessing dietary intakes of iron and related nutrients of anemic students in less developed districts.
authors: Institute of Nutrition and Food Safety, Chinese Center for Disease Control and Prevention, Beijing 100050, China. dannisy.yu@hotmail.com
authors: Dan
authors: D
authors: Yu
authors: Junsheng
authors: J
authors: Huo
authors: Jing
authors: J
authors: Sun
authors: Wexian
authors: W
authors: Li
authors: Ling
authors: L
authors: Lin
authors: Anxu
authors: A
authors: Wang
authors: Gengjun
authors: G
authors: Chen
mesh_terms: D000293:Adolescent; D018798:Anemia, Iron-Deficiency / Q000209:etiology / Q000517:prevention & control*; D002648:Child; D002681:China; D004032:Diet; D015930:Diet Records; D004034:Diet Surveys; D005260:Female; D006801:Humans; D019266:Iron, Dietary / Q000008:administration & dosage*; D008297:Male; D015203:Reproducibility of Results; D013334:Students; D011795:Surveys and Questionnaires
chemical_list: D019266:Iron, Dietary