Bias in dietary-report instruments and its implications for nutritional epidemiology
Bias in dietary-report instruments and its implications for nutritional epidemiology
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DOI：
10.1079/phn2002383
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发表时间：
2002-12-01
影响因子：
3.2
通讯作者：
Carroll, RJ
中科院分区：
文献类型：
--
作者：
Kipnis, V;Midthune, D;Carroll, RJ
目的：以尿氮排泄作为蛋白质摄入量的参考生物标志物，评价膳食评估工具中的测量误差结构，并探讨其对营养研究的影响。设计：膳食评估方法包括不同的食物频率问卷（FFQ）和传统的膳食报告参考工具，如一系列24小时回忆、4天称重食物记录或7天日记。欧洲癌症前瞻性研究（EPIC）中的六项原始试点验证研究，以及英国医学研究理事会（MRC）在诺福克队列中进行的两项验证研究，该队列后来加入为EPIC的协作组成队列。受试者：来自八项验证研究中的每项研究的样本约为100至200名年龄在35-74岁的女性和男性。在评估蛋白质摄入量时，所有传统的膳食报告参考方法都违反了FFQ中有效参考工具的关键要求，用于评估和调整膳食测量误差。他们表现出系统性偏差，部分依赖于真实摄入量，部分是个人特定的，与FFQ中的个人特定偏差相关。使用饮食报告方法作为参考工具产生了大量的高估（高达230%）的FFQ与真实的日常摄入量的相关性和严重低估（高达240%）的衰减程度的FFQ为基础的对数相对风险。膳食评估工具中测量误差对设计的影响，营养研究的分析和解释可能比之前估计的要大得多，至少在蛋白质摄入量方面是这样。
Objective: To evaluate measurement error structure in dietary assessment instruments and to investigate its implications for nutritional studies, using urinary nitrogen excretion as a reference biomarker for protein intake.Design: The dietary assessment methods included different food-frequency questionnaires (FFQs) and such conventional dietary-report reference instruments as a series of 24-hour recalls, 4-day weighed food records or 7-day diaries.Setting: Six original pilot validation studies within the European Prospective Investigation of Cancer (EPIC), and two validation studies conducted by the British Medical Research Council (MRC) within the Norfolk cohort that later joined as a collaborative component cohort of EPIC.Subjects: A sample of approximately 100 to 200 women and men, aged 35-74 years, from each of eight validation studies.Results: In assessing protein intake, all conventional dietary-report reference methods violated the critical requirements for a valid reference instrument for evaluating, and adjusting for, dietary measurement error in an FFQ. They displayed systematic bias that depended partly on true intake and partly was person-specific, correlated with person-specific bias in the FFQ. Using the dietary-report methods as reference instruments produced substantial overestimation (up to 230%) of the FFQ correlation with true usual intake and serious underestimation (up to 240%) of the degree of attenuation of FFQ-based log relative risks.Conclusion: The impact of measurement error in dietary assessment instruments on the design, analysis and interpretation of nutritional studies may be much greater than has been previously estimated, at least regarding protein intake.