This manuscript aimed to develop a brief 2-item screening tool to identify Brazilian households that include families with children at risk for food insecurity. Psychometric analyses including sensitivity, specificity, positive and negative predictive value, accuracy, and ROC curves were used to test combinations of questions to determine the most effective screener to assess households at risk for food insecurity when compared to a gold standard scale. Participants included National Demographic Health Survey on Women and Children (PNDS-2006) surveyed households with a valid Brazilian Household Food Insecurity Measurement Scale (EBIA) response. The sample included 3,920 households representing 11,779,686 households when expanded using PNDS sample weights. With overall prevalence of food insecurity at 21%, a Brazilian 2-item food-insecurity screen showed sensitivity of 79.31%, specificity of 92.95%, positive predictive value of 74.62%, negative predictive value of 94.50% and ROC area 86.13%. This screen also presented high convergent validity for children’s nutrition and health variables when compared with the gold standard, the EBIA full scale. Based on its ability to detect households at risk for food insecurity, a 2-item screening tool is recommended for widespread adoption as a screening measure throughout Brazil, especially when rapid decision-making has been made fundamental, as under the COVID-19 pandemic. This screener can enable providers to accurately identify families at risk for food insecurity and promptly intervene to prevent or ameliorate adverse health and developmental consequences associated with food insecurity and swiftly respond to crises.

Objetivo Os objetivos do trabalho foram avaliar a validade interna e a capacidade preditiva da escala de segurança alimentar de seis itens aplicada a adolescentes. Métodos Foi um estudo transversal com amostra representativa de adolescentes brasileiros (N=14.690), realizado em escolas públicas e privadas nas 26 capitais de estados brasileiros e no Distrito Federal por meio de questionário online. Resultados A maior parte dos respondentes era do sexo feminino (53,2%), com idade média de 14,4 anos, sendo 72,7% de escolas públicas. O comportamento da escala, observado pelo modelo de Rasch, foi melhor sem o item cinco, apresentando valores ótimos de Infit e nível de severidade crescente entre os itens. O alfa de Cronbach foi 0,77, e as análises do funcionamento diferencial dos itens mostraram comportamento dos itens semelhante entre os subgrupos avaliados. A análise fatorial mostrou a unidimensionalidade do instrumento. Conclusão Foi proposta a retirada do item cinco e novos pontos de corte para a escala curta de segurança alimentar. A escala curta de segurança alimentar é válida e confiável para mensurar insegurança alimentar domiciliar entre adolescentes brasileiros.

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.