食事調査の精度向上に関する疫学研究 : 3日間食事記録法と写真および面接を併用する修正法との比較

Abstract

To evaluate the accuracy improvement of a dietary survey focused on estimation of dietary intake, the author compared data from the 3-day diet record method (3DR method) with data from a modification of the method supplemented with photography and interviews (modified 3DR method). A dietary survey using the 3DR method was performed on 210 first or second grade students of a women's university during April 2001 to January 2003 using the 3DR question/answer form at each season. As the modified 3DR method, each of the students was also required to take photographs of her meals before and after comsumption, and participate in an interview with a registered nutritionist. Eighty-five completed answer forms were finally collected, and the data of 1020 days in total were analyzed. The results were as follows. 1. Both energy and nutrient intakes were estimated as significantly higher in 18 of the 37 items by the 3DR method compared with the modified 3DR method. However, differences between the values estimated by these two methods were within at most 4%. 2.The proportion of discrepancy between the data obtained by the two methods, analyzed by quartiles, was highest for carbohydrates at 24.2% (weighted kappa = 0.68) and lowest for calcium at 6.5% (weighted kappa = 0.91). 3.Seasonal fluctUation in the energy intake-adjusted nutrients intakes was observed for only 6 out of 36 items by the 3DR method, but for 10 items by the modified 3DR method. These results suggest that the modified 3DR method is not necessarily superior to the simple 3DR method in a mass epidemiological study.