Comparison of relative validity of food group intakes estimated by comprehensive and brief-type self-administered diet history questionnaires against 16 d dietary records in Japanese adults

Objective: To compare the relative validity of food group intakes derived from a comprehensive self-administered diet history questionnaire (DHQ) and a brief-type DHQ (BDHQ) developed for the assessment of Japanese diets during the previous month using semi-weighed dietary records (DR) as a reference method. Design: Between November 2002 and September 2003, a 4 d DR (covering four non-consecutive days), a DHQ (150-item semi-quantitative questionnaire) and a BDHQ (fifty-eight-item fixed-portion-type questionnaire) were completed four times (once per season) at 3-month intervals. Setting: Three areas in Japan: Osaka, Nagano and Tottori. Subjects: Ninety-two Japanese women aged 31-69 years and ninety-two Japanese men aged 32-76 years. Results: Median food group intakes were estimated well for approximately half of the food groups. No statistically significant differences were noted between a 16 d DR and the first DHQ (DHQ1) or between the DR and the first BDHQ (BDHQ1) in fifteen (44%) and fifteen (52%) food items for women and in fourteen (41%) and sixteen (55%) food items for men, respectively, indicating that both questionnaires estimated median values reasonably well. Median Spearman's correlation coefficients with the DR were 0.43 (range: -0.09 to 0.77) for DHQ1 and 0.44 (range: 0.14 to 0.82) for BDHQ1 in women, with respective values of 0.44 (range: 0.08 to 0.87) and 0.48 (range: 0.22 to 0.83) in men, indicating reasonable ranking ability. Similar results were observed for mean values of the four DHQ and BDHQ. Conclusions: In terms of food intake estimates, both the DHQ and the BDHQ showed reasonable validity.