CI&DETS, Polytechnic Institute of Viseu, Portugal.
Faculty of Health Sciences, Maimonides University, Argentina.
Public Health. 2016 Sep;138:108-18. doi: 10.1016/j.puhe.2016.03.031. Epub 2016 May 10.
Because there is scientific evidence that an appropriate intake of dietary fibre should be part of a healthy diet, given its importance in promoting health, the present study aimed to develop and validate an instrument to evaluate the knowledge of the general population about dietary fibres.
The present study was a cross sectional study.
The methodological study of psychometric validation was conducted with 6010 participants, residing in 10 countries from three continents. The instrument is a questionnaire of self-response, aimed at collecting information on knowledge about food fibres. Exploratory factor analysis (EFA) was chosen as the analysis of the main components using varimax orthogonal rotation and eigenvalues greater than 1. In confirmatory factor analysis by structural equation modelling (SEM) was considered the covariance matrix and adopted the maximum likelihood estimation algorithm for parameter estimation.
Exploratory factor analysis retained two factors. The first was called dietary fibre and promotion of health (DFPH) and included seven questions that explained 33.94% of total variance (α = 0.852). The second was named sources of dietary fibre (SDF) and included four questions that explained 22.46% of total variance (α = 0.786). The model was tested by SEM giving a final solution with four questions in each factor. This model showed a very good fit in practically all the indexes considered, except for the ratio χ(2)/df. The values of average variance extracted (0.458 and 0.483) demonstrate the existence of convergent validity; the results also prove the existence of discriminant validity of the factors (r(2) = 0.028) and finally good internal consistency was confirmed by the values of composite reliability (0.854 and 0.787).
This study allowed validating the KADF scale, increasing the degree of confidence in the information obtained through this instrument in this and in future studies.
鉴于膳食纤维在促进健康方面的重要性，有科学证据表明，适当摄入膳食纤维应成为健康饮食的一部分。因此，本研究旨在开发和验证一种评估一般人群膳食纤维知识的工具。
本研究为横断面研究。
本研究的心理测量验证方法学研究共纳入来自三大洲 10 个国家的 6010 名参与者。该工具是一种自我报告的问卷，旨在收集有关食物纤维知识的信息。采用方差极大正交旋转和特征值大于 1 的探索性因子分析（EFA）作为主要成分分析。在结构方程模型（SEM）的验证性因子分析中，考虑了协方差矩阵，并采用最大似然估计算法进行参数估计。
探索性因子分析保留了两个因素。第一个因素称为膳食纤维与促进健康（DFPH），包括 7 个问题，解释了总方差的 33.94%（α=0.852）。第二个因素称为膳食纤维来源（SDF），包括 4 个问题，解释了总方差的 22.46%（α=0.786）。通过 SEM 测试模型，最终在每个因素中得到 4 个问题的解决方案。该模型在几乎所有考虑的指标中都表现出非常好的拟合度，除了卡方自由度比（χ2/df）。平均方差提取值（0.458 和 0.483）表明存在收敛有效性；结果还证明了因子的判别有效性的存在（r2=0.028），最后通过综合可靠性值（0.854 和 0.787）确认了良好的内部一致性。
本研究验证了 KADF 量表，增加了通过该工具在本研究和未来研究中获得的信息的可信度。
