基于在校大学生在线24小时膳食问卷调查数据有效性研究

目的 在接受高等教育的人群中验证在线24h膳食调查问卷(ODQ)相较于面对面24h膳食调查(FDR)膳食数据的有效性。方法 采用整群随机抽样的方法,抽取四川大学142名在校大学生,在同一天之内分别进行ODQ及FDR调查。通过计算ODQ与FDR间膳食摄入的个体平均差异、Spearman相关系数、交叉表一致性检验,Bland-Altman图等方法,评价两种方法之间膳食能量及常见营养素摄入量的相关性和一致性。结果 ODQ法估计的膳食能量及营养素摄入量均低于FDR(P<0.05)。 两方法各膳食摄入量间的秩相关系数在0.54~0.74之间(P<0.05),两方法间膳食能量及营养素摄入被分类到相同或相邻的四分位数组的比例从维生素A的82.4%到维生素PP的93%,而被错误分类的比例均在5%以下,加权kappa系数分布在0.41~0.64间,呈现中度到高度的一致性。Bland-Altman图表明两方法间膳食能量及各营养素摄入呈现良好的一致性。结论 本研究表明在线24h膳食问卷在群体水平上调查大学生膳食能量和营养素摄入时具有良好的有效性。

Relative validity of an online 24 hours dietary recall questionnaire

Objective To determine the relative validity of an online 24 hours dietary recall questionnaire(ODQ)designed to assess energy and nutrient intake among college students compared with a face to face 24 hours dietary recall(FDR).Methods A total of 142 college students from Sichuan University were recruited by cluster sampling to complete the ODQ and the FDR within one day respectively.Estimations of individual mean differences,Spearman's correlation coefficients,cross-classifications and Bland-Altman plots were used to assess the agreement between the intakes of energy and common nutrients obtained from the ODQ and the FDR.Results Energy and nutrients intakes were lower in ODQ compared to FDR(P<0.05).For all dietary intakes,Spearman rank correlation coefficients between the ODQ and the FDR ranged from 0.54 to 0.74(P<0.05).The proportion of participants correctly classified into quartiles ranged from 82.4% for vitamin A intake to 93% for vitamin PP intake,and the percentage of misclassification was 5 % or less.The weighted kappa coefficients ranking the participants ranged from 0.41 to 0.64.The Bland-Altman plots indicated good agreement for all dietary intakes estimated from the ODQ.Conclusion This study suggests that an online 24 hours dietary questionnaire could be a valid tool for estimating the energy and nutrients intakes among college students in China at the group level.