Relative validity of a semi-quantitative food frequency questionnaire versus 28 day weighed diet records in Japanese female dietitians

Objective: To assess the relative validity of a semi-quantitative food freq uency questionnaire (SQFFQ) against 28 day weighed diet records (WDRs). Subjects and methods: The SQFFQ was administered to 106 (21 male and 85 fem ale) Japanese dietitians in Aichi Prefecture in autumn, 1996 and four-seaso n consecutive 7 day WDRs were carried out during 1996-1997. We evaluated va lidity of intakes of 15 foods and 31 macro- and micro-nutrients based on th e SQFFQ against those according to 28 day WDRs among 79 Japanese female die titians. Results: Mean daily intakes of selected foods and nutrients determined by t he SQFFQ were generally equivalent to those measured by 28 day WDRs. Pearso n's de-attenuated correlation coefficients (CCs) with log-transformation an d energy-adjustment between intakes of selected foods and nutrients quantif ied by the SQFFQ and 28 day WDRs (minimum-median-maximum) ranged from 0.17 (beverages) -0.52 to 0.74 (rice), and Spearman's rank CCs with energy-adjus tment ranged from 0.28 (confectionery) -0.42 to 0.68 (rice). Respective Pea rson's CCs for intakes of nutrients were 0.28 (PUFAs)-0.51 to 0.73 (magnesi um), and Spearman's rank CCs ranged from 0.23 (n-3 PLTFAs)-0.45 to 0.71 (ma gnesium). Favorably higher agreement for intakes of foods/nutrients was ach ieved along with lower disagreement. Conclusions: Satisfactorily higher relative validity was attained in Japane se female dietitians with the SQFFQ. This calibrated questionnaire seems th erefore appropriate for administration to Japanese dietitians to clarify as sociations between diet and health/disease. Sponsorship: A grant-in-aid from the Ministry of Education, Science, Sports and Culture (06454242). Descriptors: Japanese female dietitians; relative validity/calibration; sem i-quantitative food frequency questionnaire; weighed diet records.