title: Validity of Short and Long Self-Administered Food Frequency Questionnaires in Ranking Dietary Intake in Middle-Aged and Elderly Japanese in the Japan Public Health Center-Based Prospective Study for the Next Generation (JPHC-NEXT) Protocol Area.
abstract: BACKGROUND
  Longitudinal epidemiological studies require both the periodic update of intake information via repeated dietary survey and the minimization of subject burden in responding to questionnaires. We developed a 66-item Food Frequency Questionnaire (short-FFQ) for the Japan Public Health Center-based prospective Study for the Next Generation (JPHC-NEXT) follow-up survey using major foods from the FFQ developed for the original JPHC Study. For the JPHC-NEXT baseline survey, we used a larger 172-item FFQ (long-FFQ), which was also derived from the JPHC-FFQ. We compared the validity of ranking individuals by levels of dietary consumption by these FFQs among residents of selected JPHC-NEXT study areas.
  
  
  METHODS
  From 2012 to 2013, 240 men and women aged 40-74 years from five areas in the JPHC-NEXT protocol were asked to respond to the long-FFQ and provide 12-day weighed food records (WFR) as reference; 228 also completed the short-FFQ. Spearman's correlation coefficients (CCs) between estimates from the FFQs and WFR were calculated and corrected for intra-individual variation of the WFR.
  
  
  RESULTS
  Median CC values for energy and 53 nutrients for the short-FFQ for men and women were 0.46 and 0.44, respectively. Respective values for the long-FFQ were 0.50 and 0.43. Compared with the long-FFQ, cross-classification into exact plus adjacent quintiles with the short-FFQ ranged from 68% to 91% in men and 58% to 85% in women.
  
  
  CONCLUSIONS
  Similar to the long-FFQ, the short-FFQ provided reasonably valid measures for ranking middle-aged and elderly Japanese for many nutrients and food groups. The short-FFQ can be used in follow-up surveys in prospective cohort studies aimed at updating diet rank information.
authors.affiliation: Department of Community Preventive Medicine, Niigata University Graduate School of Medical and Dental Sciences.
authors.forename: Yuta
authors.initials: Y
authors.lastname: Yokoyama
authors.forename: Ribeka
authors.initials: R
authors.lastname: Takachi
authors.forename: Junko
authors.initials: J
authors.lastname: Ishihara
authors.forename: Yuri
authors.initials: Y
authors.lastname: Ishii
authors.forename: Shizuka
authors.initials: S
authors.lastname: Sasazuki
authors.forename: Norie
authors.initials: N
authors.lastname: Sawada
authors.forename: Yurie
authors.initials: Y
authors.lastname: Shinozawa
authors.forename: Junta
authors.initials: J
authors.lastname: Tanaka
authors.forename: Erika
authors.initials: E
authors.lastname: Kato
authors.forename: Kaori
authors.initials: K
authors.lastname: Kitamura
authors.forename: Kazutoshi
authors.initials: K
authors.lastname: Nakamura
authors.forename: Shoichiro
authors.initials: S
authors.lastname: Tsugane
mesh_terms: D000328:Adult; D000368:Aged; D004032:Diet / Q000706:statistics & numerical data*; D004034:Diet Surveys; D005260:Female; D006801:Humans; D007564:Japan; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D011634:Public Health; D015203:Reproducibility of Results