Freedman L S, Carroll R J, Wax Y
Biometry Branch, DCPC, National Cancer Institute, Bethesda, MD.
Am J Epidemiol. 1991 Aug 1;134(3):310-20. doi: 10.1093/oxfordjournals.aje.a116086.
Knowledge of the regression relation between dietary intake reported on a food frequency questionnaire and true average intake is useful in interpreting results from nutritional epidemiologic studies and in planning such studies. Studies which validate a questionnaire against a food record may be used to estimate this regression relation provided the food record is completed by each subject on at least two occasions. Using data collected from women aged 45-69 years during 1985-1986 in the pilot study of the Women's Health Trial, the authors show how variation in diet over time and intraindividual correlation between a questionnaire and food record obtained close together in time affects the estimation of the regression. The authors' method provides estimates of the regression slope and the questionnaire "bias" that are corrected for these effects, together with standard errors. A computer program in the SAS language, for carrying out the analysis, is provided.
了解食物频率问卷所报告的膳食摄入量与真实平均摄入量之间的回归关系，对于解释营养流行病学研究结果及规划此类研究很有用处。如果每个受试者至少两次完成食物记录，那么通过与食物记录对比来验证问卷的研究可用于估计这种回归关系。利用1985 - 1986年在女性健康试验的试点研究中收集的45 - 69岁女性的数据，作者展示了随着时间推移饮食的变化以及在相近时间获得的问卷与食物记录之间的个体内相关性如何影响回归估计。作者的方法提供了针对这些影响进行校正的回归斜率估计值和问卷“偏差”，以及标准误差。还提供了一个用SAS语言编写的用于进行分析的计算机程序。
