Welch A A, Luben R, Khaw K T, Bingham S A
Department of Public Health and Primary Care, University of Cambridge, Strangeways Site, Wort's Causeway, Cambridge, UK.
J Hum Nutr Diet. 2005 Apr;18(2):99-116. doi: 10.1111/j.1365-277X.2005.00593.x.
Food frequency questionnaires (FFQs) are widely used in nutritional epidemiology but no papers detail the development of the supporting programs and nutritional databases. The principles involved in data collection, processing and treatment of the European Prospective Investigation into Cancer Study (EPIC)-Norfolk Study FFQ and development of the structure and content of the Compositional Analyses from Frequency Estimates (CAFE) program for calculating nutrient intakes are described. Extreme nutrient values and derivation of cut-points for data exclusion are also discussed.
The FFQ was sent to 25,637 participants. To exclude extreme (nonphysiological) outliers of nutrient intakes, the extreme top and bottom 0.5% of the ratio of energy intake to estimated basal metabolic rate was used.
The CAFE computer program modifies nutrient intake according to specific fats used in food preparation and the amount of visible fat on meat. It incorporates different breakfast cereals and distinguishes between text for brands and types. After exclusion of outliers of nutrient intake some extreme values remained for energy, carbohydrate, protein, fat and alcohol, because of high reported frequencies of certain foods.
The features of CAFE include flexible, updateable, databases and a novel method for matching text. The effect of extreme nutrient values on the accuracy of the FFQ in estimating diet in nutritional epidemiology should be investigated further.
食物频率问卷（FFQ）在营养流行病学中被广泛使用，但尚无文献详细介绍其配套程序和营养数据库的开发情况。本文描述了欧洲癌症前瞻性调查研究（EPIC）-诺福克研究FFQ在数据收集、处理和分析过程中所涉及的原则，以及用于计算营养素摄入量的频率估计成分分析（CAFE）程序的结构和内容的开发情况。此外，还讨论了极端营养素值以及数据排除切点的推导。
FFQ被发送给25637名参与者。为排除营养素摄入量的极端（非生理性）异常值，采用能量摄入量与估计基础代谢率比值的极端最高和最低0.5%作为排除标准。
CAFE计算机程序根据食物制备中使用的特定脂肪和肉类上可见脂肪的量来调整营养素摄入量。它纳入了不同的早餐谷物，并区分了品牌和类型的文本。在排除营养素摄入量的异常值后，由于某些食物的报告频率较高，能量、碳水化合物、蛋白质、脂肪和酒精仍存在一些极端值。
CAFE的特点包括灵活、可更新的数据库以及一种新颖的文本匹配方法。极端营养素值对营养流行病学中FFQ估计饮食准确性的影响应进一步研究。
