title: Relative validity and reproducibility of a food frequency questionnaire used in pregnant women from a rural area of China.
abstract: OBJECTIVE
  Food frequency questionnaires are relatively inexpensive, easy and quick to administer, but the construction of a food frequency questionnaire that can capture Chinese food habits is challenging given the diverse lifestyle and eating habits in different parts of the country. The aim of this study was to assess the validity and reproducibility of a self-administered food frequency questionnaire against a 3-day dietary recall in a rural region of western China.
  
  
  METHODS
  Prospective cohort study.
  
  
  METHODS
  Chinese maternal and child healthcare hospital.
  
  
  METHODS
  A total of 168 healthy pregnant women.
  
  
  METHODS
  Pregnant women completed a food frequency questionnaire at 16-24 weeks gestation, and again at 29-31 weeks; during weeks 26-27 they completed a 3-day dietary recall.
  
  
  RESULTS
  In general, mean intake was higher when assessed with food frequency questionnaires compared with dietary recall. Spearman and intra-class correlation coefficients between the two food frequency questionnaires ranged from 0.31 to 0.69 and from 0.27 to 0.79, respectively. For the second food frequency questionnaire and the dietary recall, the crude and de-attenuated Spearman correlations ranged from 0.12 to 0.55 and 0.14 to 0.58, respectively. The correlation both between the two food frequency questionnaires and between the second food frequency questionnaire and the dietary recall decreased after adjustment for energy. Ranking women, 31-57% and 1-8% were classified into the same and the opposite quartile, respectively, by both food frequency questionnaires; 30-45% and 1-11% were classified into the same and the opposite quartile respectively for the second food frequency questionnaire and dietary recall.
  
  
  CONCLUSIONS
  The food frequency questionnaire showed good reproducibility and correlations with dietary recall; it is useful for ranking study participants according to dietary intake, which is of great importance to future etiological studies in this cohort.
authors: School of Public Health, Fudan University, Shanghai, China; Department of Epidemiology and Social Science on Reproductive Health, National Population and Family Planning Key Laboratory of Contraceptive Drugs and Devices, Shanghai Institute of Planned Parenthood Research, Shanghai, China.
authors: Min
authors: M
authors: Li
authors: Thorhallur I
authors: TI
authors: Halldorsson
authors: Anne A
authors: AA
authors: Bjerregaard
authors: Yan
authors: Y
authors: Che
authors: Yanyan
authors: Y
authors: Mao
authors: Wenfu
authors: W
authors: Hu
authors: Yu
authors: Y
authors: Wang
authors: Weijin
authors: W
authors: Zhou
authors: Sjúrdur F
authors: SF
authors: Olsen
authors: Marin
authors: M
authors: Strøm
mesh_terms: D000328:Adult; D002681:China; D003710:Demography; D004034:Diet Surveys; D005247:Feeding Behavior; D005260:Female; D006801:Humans; D011247:Pregnancy; D011446:Prospective Studies; D015203:Reproducibility of Results; D012424:Rural Population
keywords: Food frequency questionnaire; dietary recall; pregnancy; relative validity; reproducibility