Development of a dietary index based on the Brazilian Cardioprotective Nutritional Program (BALANCE)

Abstract Background The diet of the Brazilian Cardioprotective Nutritional Program (BALANCE) classifies food into four groups and sets the daily amount to be consumed. The dietary approach of BALANCE is different from other dietary recommendations; therefore, it is not possible to use existing dietary indexes (DI) to assess patient’s adequacy to BALANCE diet. For this reason, it is important to develop a specific dietary index based on BALANCE diet. This study aims to describe the development of the BALANCE DI, evaluate its internal consistency, construct and content validity and population characteristics associated with the index. Methods We analyzed baseline data from the BALANCE randomized clinical trial (https://www.clinicaltrials.gov/; NCT01620398). The four food groups of the diet were adopted as index components. Points ranging from 0 to 10 were given to each index component. Internal consistency was evaluated by correlation coefficients between total score and component scores, as well as Cronbach’s Alpha. Content and construct validity were assessed by checking how nutrients are associated with the index and if the index could distinguish between groups with known differences in diet, respectively. Crude and adjusted linear regression analyses were performed to evaluate population characteristics associated with the index. Results The analysis included 2044 subjects (58.6% men). The average of the total index was higher among women (p 0.40. Cronbach’s alpha coefficient was 0.66. High scores in the index were inversely associated (p