Thompson Frances E, Midthune Douglas, Williams Geoffrey C, Yaroch Amy L, Hurley Thomas G, Resnicow Ken, Hebert James R, Toobert Deborah J, Greene Geoffrey W, Peterson Karen, Nebeling Linda
Applied Research Program, Division of Cancer Control and Population Sciences, National Cancer Institute, Bethesda, MD 20892-7344, USA.
J Nutr. 2008 Jan;138(1):193S-199S. doi: 10.1093/jn/138.1.193S.
The need for an inexpensive measure of dietary intake in intervention studies led to evaluation of the National Cancer Institute (NCI) Percentage Energy from Fat short instrument (PFat) in a subgroup of the Behavioral Change Consortium (BCC) intervention sites. The PFat's performance was evaluated using multiple nonconsecutive 24-h dietary recalls (24HR) as a reference instrument among participants at baseline in 4 demographically diverse intervention sites of the BCC. Mean estimates of percentage energy from fat for 24HR and PFat were within 2.1 percentage points of each other in all but 2 site/gender comparisons. 24HR and PFat estimates were not significantly different (P < 0.05) among men for 2 of 3 sites, and among women for 2 of 4 sites. Deattenuated Pearson correlation coefficients for the PFat and true intake (as estimated from the 24HR using a measurement error model) were significantly different from 0 (P < 0.05) for men and women in all sites, ranging from 0.52 to 0.77 among men and 0.36 to 0.59 among women. Besides gender and site, no other factors examined (age, education, smoking status, and BMI) consistently moderated validity estimates. If accurate assessment of diet at baseline (and presumably at follow-up) is essential, a more detailed instrument such as multiple 24HR may be warranted. The question of whether the PFat adequately measures change in diet is addressed in another article in this supplement.
在干预研究中，由于需要一种衡量饮食摄入量的低成本方法，因此在行为改变联盟（BCC）干预点的一个子集中对美国国立癌症研究所（NCI）的脂肪能量百分比简易工具（PFat）进行了评估。在BCC的4个人口统计学特征各异的干预点，以多次非连续的24小时饮食回忆法（24HR）作为参考工具，对基线期参与者的PFat性能进行了评估。在所有的站点/性别比较中，除了2组外，24HR和PFat的脂肪能量百分比平均估计值相差在2.1个百分点以内。在3个站点中的2个站点，男性的24HR和PFat估计值无显著差异（P<0.05）；在4个站点中的2个站点，女性的24HR和PFat估计值无显著差异。在所有站点中，男性和女性的PFat与真实摄入量（使用测量误差模型从24HR估计）的去衰减Pearson相关系数均显著不同于0（P<0.05），男性的相关系数范围为0.52至0.77，女性为0.36至0.59。除了性别和站点外，所考察的其他因素（年龄、教育程度、吸烟状况和BMI）均未持续调节有效性估计值。如果在基线期（可能在随访期）准确评估饮食至关重要，那么可能需要使用更详细的工具，如多次24HR。本增刊的另一篇文章探讨了PFat是否能充分衡量饮食变化的问题。
