Translation, adaptation and validation of a Portuguese version of the Moorehead-Ardelt Quality of Life Questionnaire II.

The prevalence of obesity has increased worldwide. An assessment of the impact of obesity on health-related quality of life (HRQoL) requires specific instruments. The Moorehead-Ardelt Quality of Life Questionnaire II (MA-II) is a widely used instrument to assess HRQoL in morbidly obese patients. The objective of this study was to translate and validate a Portuguese version of the MA-II.The study included forward and backward translations of the original MA-II. The reliability of the Portuguese MA-II was estimated using the internal consistency and test-retest methods. For validation purposes, the Spearman's rank correlation coefficient was used to evaluate the correlation between the Portuguese MA-II and the Portuguese versions of two other questionnaires, the 36-item Short Form Health Survey (SF-36) and the Impact of Weight on Quality of Life-Lite (IWQOL-Lite).One hundred and fifty morbidly obese patients were randomly assigned to test the reliability and validity of the Portuguese MA-II. Good internal consistency was demonstrated by a Cronbach's alpha coefficient of 0.80, and a very good agreement in terms of test-retest reliability was recorded, with an overall intraclass correlation coefficient (ICC) of 0.88. The total sums of MA-II scores and each item of MA-II were significantly correlated with all domains of SF-36 and IWQOL-Lite. A statistically significant negative correlation was found between the MA-II total score and BMI. Moreover, age, gender and surgical status were independent predictors of MA-II total score.A reliable and valid Portuguese version of the MA-II was produced, thus enabling the routine use of MA-II in the morbidly obese Portuguese population.