Assessing factorial and convergent validity and reliability of a food behaviour checklist for Spanish-speaking participants in US Department of Agriculture nutrition education programmes

Abstract

Objective: To assess convergent validity, factorial validity, test-retest reliability and internal consistency of a diet quality food behaviour checklist (FBC) for low-literate, low-income Spanish speakers.

Design: Participants (n 90) completed three dietary recalls, the Spanish-language version of the US Department of Agriculture (USDA) Household Food Security Survey Module (HFSSM) and the Spanish-language FBC. Factor structure was examined using principal component analysis. Spearman correlation coefficients between FBC item responses and nutrient intakes from 24 h recalls were used to estimate convergent validity. Correlation coefficients were also calculated between FBC item responses at two time points in another group of participants (n 71) to examine test-retest reliability. Cronbach's α coefficient was determined for items within each sub-scale.

Setting: Non-profit community agencies serving low-income clients, migrant farm worker camps and low-income housing sites in four California counties.

Subjects: Spanish-speaking women (n 161) who met income eligibility for the SNAP-Ed (Supplemental Nutrition Assistance Program-Education).

Results: Factor analysis resulted in six sub-scales. Responses to nineteen food behaviour items were significantly correlated with hypothesized 24 h recall data (with a maximum correlation of 0·44 for drinking milk and calcium) or the USDA HFSSM (0·42 with the food security item). Coefficients for test-retest reliability ranged from 0·35 to 0·79. Cronbach's α ranged from 0·49 for the diet quality sub-scale to 0·80 for the fruit and vegetable sub-scale.

Conclusions: The twenty-two-item FBC and instruction guide will be used to evaluate USDA community nutrition education interventions with low-literate Spanish speakers. This research contributes to the body of knowledge about this at-risk population in California.