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

Highlights

• MDS-Brazil translation and cross-cultural adaptation was performed.

• Substantial MDS-Brazil reproducibility was found in adults with diabetes.

• Internal consistency was acceptable in adults with diabetes.

Abstract

Background and aim

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.

Methods

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.

Results

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.

Conclusions

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.

Introduction

Diabetes mellitus (DM) is a group of metabolic diseases characterized by hyperglycemia resulting from defects in insulin secretion, insulin action, or both [1]. In 2019, the International Diabetes Federation (IDF) estimated that 463 million people have DM in the world. Brazil has the largest number of adults with DM in South and Central America (16.8 million), representing the fifth position in global prevalence of the disease and an average annual expenditure on health per person of US$3117.00 [2,3].

A healthy lifestyle and diet are essential to control DM and to reduce the risk of developing cardiovascular diseases (CVD) [4]. The Mediterranean diet (MedDiet) is one of the eating patterns considered effective in this class of disease [5]. The MedDiet is characterized by low consumption of saturated fat, high intake of unsaturated fatty acids (with oil, fish, or nuts, for example) and high intake of antioxidants [6,7]. The beneficial impact of the MedDiet on general health, including cardiovascular health, has been established [[8], [9], [10]], as well as in the primary prevention of CVD [11]. Furthermore, the MedDiet is associated with better glycemic control and a reduction in cardiovascular risk factors, suggesting that it is suitable for the general control of diabetes type 2 [12,13]. These beneficial effects of the MedDiet in individuals with DM mainly consist in their synergy between various nutrients and food, and not in any individual component [14].

A multicenter clinical trial from Spain called “Prevención con Dieta Mediterránea” (PREDIMED study) designed to assess the effects of the traditional Mediterranean diet on primary prevention of cardiovascular disease presented one tool to quickly evaluate the diet: the 14-point Mediterranean diet adherence screener (MEDAS) [15,16]. This instrument has been used as a screening tool to assess dietary intake with low spent resources [[15], [16], [17]]. It consists of 12 questions applied as an interview about the frequency of food consumption and 2 questions about eating habits considering the characteristics of the Spanish Mediterranean diet [17], and was validated in people with DM and risk of cardiovascular disease. Recent studies presented validated versions of the MEDAS in German [18] and English [19]. A Portuguese-Brazilian version of the MEDAS was recently published, however its measurement properties have not been analyzed [20].

Ghisi et al. (2018) adapted the MEDAS by changing its presentation to a pictorial format and by modifying the phrasal structures to transform it into a self-administered version [21]. The reformulated instrument received the name of the Mediterranean Diet Scale (MDS), and was validated in a cardiac rehabilitation population in Canada. According to the authors, the MDS was rewritten into a simpler and more illustrated language to be considered more opportune and has the potential to improve its application in several settings and different countries [21]. The MDS is available at: www.tandfonline.com/doi/suppl/10.1080/09637486.2018.1486392?scroll=top.

Although the MedDiet is not traditional in Brazil, the concept of eating a variety of natural or minimally processed foods can be achieved as nutritional interventions indicated for the Brazilian population in general and for DM individuals [22]. The MDS is a questionnaire with characteristics which can contribute to the multidimensional assessment of patients with diabetes by the multidisciplinary team, as well as to evaluate the effect of specific educational and nutritional interventions. Taking into consideration the high prevalence of DM in Brazil and the positive effects of the MedDiet for people with DM, this study was performed to translate and cross-culturally adapt the Canadian version of the MDS and subsequently validate the new Brazilian-Portuguese version of the MDS.