University of Dundee, Ninewells Hospital and Medical School, Dundee, UK.
Eur J Clin Nutr. 2010 Feb;64(2):210-7. doi: 10.1038/ejcn.2009.126. Epub 2009 Nov 11.
Food labels may have an important function in communicating nutrition information and have considerable potential to influence food choice and dietary behaviour.
To assess the validity and reliability of a short (self-complete) questionnaire designed to measure consumers' use and understanding of food labels.
Questionnaire content was determined by gaps highlighted in a literature review of food labelling. Nineteen questions (49 items) assessing frequency of label reading perceived importance of food labels, regularity of dining out, desire to have nutrition information at specific catering outlets and ability to perform nutrition information tasks were formulated and presented on four pages of A4. With the exception of two open-ended questions, all items were presented as closed (field box) structures. Content validity, face validity, item analysis, repeat and internal reliability were assessed.
Nutrition experts (26) completed detailed content validity assessment, resulting in high scores for appropriateness, importance and phrasing of questions, although grammar and terminology changes were required. Face validity indicated that the questionnaire was quick to complete (<15 min), easy to follow and comprehensible. Cronbach's alpha scores (internal reliability) for questions with multiple sections ranged from 0.72 to 0.91, indicating good internal consistency. Repeat reliability testing showed Spearman's correlation coefficients ranging from 0.51 to 0.97 (all P<0.001) showing high temporal stability. Item Difficulty analysis indicated that questions (Section C only) were at an appropriate level (with P between 20 and 80% for all items). Item discrimination analysis ranged from r=0.43 to 0.70, highlighting that items were suitable for inclusion.
This questionnaire is a suitable tool for assessing consumers' use, understanding and perception of food labels.
食品标签在传达营养信息方面可能具有重要作用，并且具有很大的潜力来影响食物选择和饮食行为。
评估一种简短（自我完成）问卷的有效性和可靠性，该问卷旨在衡量消费者对食品标签的使用和理解。
问卷内容是通过对食品标签文献综述中突出的空白确定的。19 个问题（49 项）评估了阅读标签的频率、对食品标签的重要性的感知、外出就餐的规律性、希望在特定餐饮场所获得营养信息的愿望以及执行营养信息任务的能力，并在四页 A4 纸上呈现。除了两个开放式问题外，所有项目均以封闭式（字段框）结构呈现。评估了内容有效性、表面有效性、项目分析、重复和内部可靠性。
营养专家（26 名）完成了详细的内容有效性评估，对问题的适当性、重要性和措辞给予了高分，尽管需要更改语法和术语。表面有效性表明，该问卷易于完成（<15 分钟）、易于遵循且易于理解。具有多个部分的问题的克朗巴赫的α分数（内部可靠性）范围为 0.72 至 0.91，表明内部一致性良好。重复可靠性测试显示斯皮尔曼相关系数范围为 0.51 至 0.97（所有 P<0.001），表明具有高度的时间稳定性。项目难度分析表明，问题（仅 C 节）处于适当水平（所有项目的 P 值介于 20%和 80%之间）。项目区分分析范围从 r=0.43 到 0.70，突出表明项目适合纳入。
该问卷是评估消费者对食品标签的使用、理解和感知的合适工具。
