Potosky A L, Block G, Hartman A M
Division of Cancer Prevention and Control, National Cancer Institute, Bethesda, Maryland 20892.
J Am Diet Assoc. 1990 Jun;90(6):810-3.
The effect of the number of diet records used as the reference data on the apparent validity of a diet history questionnaire was examined using data from 97 participants in the Women's Health Trial feasibility study. Pearson correlation coefficients were computed between the estimates of usual individual intake from the questionnaire and estimates from the mean of three 4-day records obtained over a 1-year period, the mean of the two most recent records, and the record obtained 1 year after the start of the study. The results illustrate that the apparent validity of a questionnaire increases when it is compared with a greater number of 4-day food records. The correlations increased for most nutrients when the baseline food record was included, despite the fact that it was completed at a time not targeted by the questionnaire. These findings suggest that greater effort should be given to obtaining more diet-record days when validating other dietary assessment instruments.
利用妇女健康试验可行性研究中97名参与者的数据，研究了用作参考数据的饮食记录数量对饮食史问卷表面效度的影响。计算了问卷中个体通常摄入量估计值与在1年期间获得的3份4天记录的平均值、最近两份记录的平均值以及研究开始1年后获得的记录的估计值之间的皮尔逊相关系数。结果表明，当问卷与更多的4天食物记录进行比较时，其表面效度会提高。尽管基线食物记录是在问卷未针对的时间完成的，但当纳入该记录时，大多数营养素的相关性增加。这些发现表明，在验证其他饮食评估工具时，应更加努力获取更多天数的饮食记录。
