Takehiro Yamashita, Ryo Asaoka, Hiroto Terasaki, Naoya Yoshihara, Naoko Kakiuchi, Taiji Sakamoto
Three-year changes in sex judgment using color fundus parameters in elementary school students
PloS one
purpose review provide guidance development validation use foodfrequency questionnaires ffqs different study designs include recommendations appropriate method dietary assessment eg foodfrequency questionnaire versus weighed recorda comprehensive search electronic databases carried publications 1980 1999 findings review commented upon added group international expertsrecommendations developed aid design validation use ffqs specific details areas discussed textffqs used variety ways different study designs gold standard directly assessing validity ffqs nevertheless outcome review help wishing develop adapt ffq validate intended use