Reproducibilidad, correlación y concordancia de un cuestionario abreviado del Dietary Score

Abstract

ObjectiveThe objective of this study was to evaluate the reproducibility, correlation and concordance of the abbreviated Dietary Score (aDS) used in the IBERICAN study. Material and methodsA cross-sectional study was performed in order to assess the reproducibility of the aDS using a test-retest. Its internal consistency was evaluated using Cronbach's alpha, and reliability of the measurements using the intraclass correlation coefficient (ICC). From the food frequency questionnaire (FFQ) of the PREDIMED-Plus study, adherence to a Mediterranean diet pattern was evaluated using DS, and its correlation and agreement with aDS was assessed. In both cases the lineal regression, Bland-Altman, and kappa index techniques were used. ResultsA total of 142 subjects participated, mostly men (56.3%), with a mean age of 64.6±4.9 years. In terms of reproducibility, a Pearson correlation coefficient of 0.538 was obtained; a mean of the differences of 2.03 points, and a weighted kappa index of 0.400 (95% CI=0.295-0.577). The instrument had good internal consistency (Cronbach's alpha=0.699), as well as good reliability (CCI=0.931). The aDS had a correlation coefficient with the DS of 0.517, a mean difference of 1.19 points, and a weighted kappa index of 0.450 (95% CI=0.366-0.532). ConclusionsThe aDS has moderate reproducibility and a good correlation and agreement with the DS, so it can be a useful tool in Primary Care to assess adherence to the Mediterranean diet.