Household food insecurity in Brazilian adolescents: a validation study

Objective The objective of this study was to evaluate the internal and predictive validity of a six-item household food insecurity scale to measure food insecurity in Brazilian adolescents. Methods A cross-sectional study with a representative sample of Brazilian adolescents (N=14,690) was conducted in public and private schools in 26 state capitals and in the Federal District of Brazil using an online questionnaire. Results Most respondents were female (53.2%) with mean age of 14.4 years, and 72.7% of them attended public schools. The psychometric properties of the scale, assessed using the Rasch model, showed better response rates without the item five, exhibiting optimal Infit statistics and an increasing level of severity among the items. Cronbach's á was 0.767. Differential item functioning analyses showed similar behavior between the items in the subgroups evaluated. Factor analysis confirmed the unidimensionality of the scale. Conclusion This study proposes the removal of the item five and the inclusion of new cut-off points for this short form of the scale. The Household Food Security Scale (short form) is valid and reliable to measure household food insecurity in Brazilian adolescents.

研究目的：本研究旨在评估一款6条目家庭粮食不安全量表的内部效度与预测效度，以衡量巴西青少年群体的粮食不安全状况。
研究方法：本研究针对巴西青少年开展横断面研究，采用具有代表性的样本（N=14690），通过线上问卷在巴西26个州首府及联邦特区的公立、私立学校中完成调研。
研究结果：多数受访者为女性（53.2%），平均年龄为14.4岁，其中72.7%就读于公立学校。通过拉什（Rasch）模型对该量表的心理测量学特征进行评估，结果显示移除条目5后，量表应答表现更优，条目拟合（Infit）统计量处于最优水平，且各条目严重程度呈递增趋势。克隆巴赫α系数为0.767。项目功能差异分析显示，所评估的各亚组内条目行为表现一致。因子分析证实该量表具备单维性。
研究结论：本研究建议移除条目5，并为该简化版量表设立新的截断值。该简化版家庭粮食安全量表（Household Food Security Scale, short form）用于评估巴西青少年家庭粮食不安全状况时，具备良好的效度与信度。