[Reproducibility, correlation and concordance of the Abbreviated Dietary Score questionnaire]

The objective of this study was to evaluate the reproducibility, correlation and concordance of the abbreviated Dietary Score (aDS) used in the IBERICAN study.

A 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.

A 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).

The 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.