Brazilian Portuguese version of the Mediterranean diet scale: Translation procedures and measurement properties

The Mediterranean Diet Scale (MDS) is a questionnaire with characteristics which can contribute to the multidimensional assessment of patients with diabetes mellitus (DM) by the multidisciplinary team, as well as to evaluate the effect of specific educational and nutritional interventions. The aim of this study was to translate and perform a cross-cultural adaptation of a Canadian MDS and analyze the measurement properties of the Brazilian Portuguese version of the Mediterranean Diet Scale (MDS-Brazil) in individuals with DM in Brazil.

This was a cross-sectional study. The analyzed measurement properties were the internal consistency, floor and ceiling effects, reproducibility, and construct validity. The inclusion criteria were diagnosis of DM type 1 or type 2, literate, outpatients, and without eating restrictions.

Of the 160 volunteers included in this study, 30 participated in pretesting, and another 130 (57.7% women, 74.6% DM type 2, 56.55 ± 14.88 years) agreed to participate in the evaluation stage of the measurement properties. All items were cross-culturally adapted. A factor analysis (KMO = 0.555 and X² = 137.22; p < 0.001) extracted five factors, with no floor or ceiling effects, Cronbach's alpha = 0.42, and reproducibility ICC = 0.75.

The cross-cultural adaptation was performed maintaining the equivalences. The MDS-Brazil measurement properties showed substantial reproducibility, low internal consistency, and fair correlations of construct validity in patients with DM.