Development and validation of a physical food security tool for older adults

Authors: SASSINE, ANNIE BELLE - University Of Maryland; RABBITT, MATTHEW - Economic Research Serivce (ERS, USDA); COLEMAN-JENSEN, ALISHA - Economic Research Serivce (ERS, USDA); Moshfegh, Alanna; SAHYOUN, NADINE - University Of Maryland

Submitted to: Journal of Nutrition
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/24/2023
Publication Date: 3/1/2023
Citation: Sassine, A.J., Rabbitt, M.P., Coleman-Jensen, A., Moshfegh, A.J., Sahyoun, N.R. 2023. Development and validation of a physical food security tool for older adults. Journal of Nutrition. https://doi.org/10.1016/j.tjnut.2023.02.034.
DOI: https://doi.org/10.1016/j.tjnut.2023.02.034

Interpretive Summary: To understand food security as a whole, physical access has to be integrated in combination with the economic aspect of food insecurity and new studies are recommended to evaluate the role of social support and environmental context in relation to food. Many studies have looked at the relationship between physical functioning and household economic food insecurity and yet no studies have developed and validated a specific tool to measure the physical aspect of food insecurity. Using data from adults ages 60 and older from 2013-2018 National Health and Nutrition Examination Survey, a 6-item Physical Food Security scale was developed for assessing the severity of food insecurity due to physical function limitation in older adults (n=5892). Both internal and external validity of the tool was demonstrated resulting in a tool that has adequate psychometric properties and that can be used for rapid assessment of physical food security as its items relate to food acquisition and intake. The strength of the study is the development of a rapid tool that will allow researchers to adopt selected questions in the absence of a complete scale with confidence that the questions represent the underlying latent construct of physical access in food insecurity. The proposed 6-item Physical Food Security scale is a valid tool in capturing the physical access dimension of food insecurity.

Technical Abstract: Current measures of food insecurity focus on economic access, but not on the physical aspect of food insecurity that captures the inability to access food or prepare meals. The objective of this research was to 1) develop and internally validate a short-form Physical Food Security tool among older adults and 2) test for associations between the newly developed scale and diet quality, self-reported health, and economic food insecurity. Pooled data from adults ages 60 and older of the National Health and Nutrition Examination Survey (2013-2018) (n = 5892) were used in this study. Following the development of the Physical Food Security scale, its internal validity was tested using principal component analysis and an Item Response Theory (Rasch) model. The scale was tested for associations with the Healthy Eating Index score (HEI-2015), self-reported health and diet quality, and economic food insecurity, using weighted multivariate linear regression analysis, controlling for age, gender, ethnicity, and educational level. Results showed that three of the initial 9 items in the scale had to be removed due to high infit and/or residual correlation with other items. The resulting 6-item scale had adequate fit statistics and high reliability and categorized into 4 levels: high physical food security (49.9%), marginal physical food security (31.6%), low physical food security (13.3%), and very low physical food security (5.4%). Very low physical food security was associated with respondent’s self-reported poor health (OR=23.9, P<0.0001), self-reported poor diet (OR=3.93, P<0.0001), low and very low economic food security (OR=6.08, P<0.0001) and with lower HEI-2015 index score mean, in comparison to older adults with high physical food security (54.5 vs 57.5, P=0.022). The proposed 6-item Physical Food Security scale is a valid tool in capturing the physical access dimension of food insecurity.