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

Latinos comprise over one-third of the population in California(1). Due to higher rates of hypertension, obesity, diabetes and metabolic syndrome in Latina women, this group is at higher risk for CVD than non-Latino whites(2). Nutrition education interventions promoting dietary change have been shown to have positive effects on behaviour, thereby reducing the chronic disease burden(3). Evaluation tools to assess these dietary behaviour changes are essential. Several short dietary or behavioural assessment tools have previously been developed and reported in the nutrition literature. Their purposes include population monitoring, survey assessment and evaluation of nutrition education interventions. These tools include the National Cancer Institute's 5-a-Day for better health fruit and vegetable screener(4), Kristal et al.'s Food Behavior Checklist at the University of Washington(5), Connor et al.'s Diet Habits Survey at Oregon Health Sciences University(6), Wakimoto et al.'s brief dietary screeners at the University of California, Berkeley(7) and Townsend et al.'s Food Behavior Checklist at the University of California, Davis(8–10). This literature review found no rigorously validated Spanish-language food behaviour evaluation tools to assess diet quality. Tools for Spanish-speaking low-literacy populations are especially lacking, with only one study describing validation of a set of short FFQ in a low-literacy Spanish-speaking sample(7). There is a need for tools for US Department of Agriculture (USDA) food assistance and education programmes with a low respondent burden that can be administered in a group setting to this audience(8,9,11,12). Tools that have exhibited adequate validity and reliability in a particular population need to be re-evaluated for use in another population that differs in terms of education, income, cultural background, country of origin, language or literacy(11,13). An ideal evaluation instrument for these federal programmes should exhibit adequate validity and reliability in the target population(11,14), be sufficiently brief to avoid detracting from the education portion of the intervention, and include behaviours presented in the education sessions(9–11). The current study sought to test a food behaviour checklist in a Spanish-speaking, low-income population in California. Face validity was previously assessed and reported(15). This assessment involved rigorous methods including a comparison of five translated versions and cognitive testing interviews with low-income clients to determine their preferred word choices, resulting in a tool with low reading difficulty. Developed using visual information processing theories, this tool consisted of sixteen behavioural items with each composed of simplified text and visual. Based on our previously reported findings with an English-speaking audience(8,16), the representative visuals were used as effective substitutes for text and/or as extralinguistic information to add clarity and facilitate understanding and hence learning for a low-literate audience. Also reported was that clients preferred colour photographs with realism, shape and colour cues compared with greyscale photographs with realism, shape cues or black/white line drawings, or abstract visuals with minimal realism(8,15). The present paper examines the Spanish-language food behaviour checklist (FBC) in terms of factorial and convergent validity, internal consistency and test–retest reliability with a low-literate Spanish-speaking audience.