Cross-Validation of the Taiwan Version of the Moorehead–Ardelt Quality of Life Questionnaire II with WHOQOL and SF-36

BACKGROUND Obesity has become a major worldwide public health issue. There is a need for tools to measure patient-reported outcomes. The Moorehead-Ardelt Quality of Life Questionnaire II (MA II) contains six items. The objective of this study was to translate the MA II into Chinese and validate it in patients with morbid obesity. METHODS The MA II was translated into Chinese and back-translated into English by two language specialists to create the Taiwan version, which was validated by correlations with two other generic questionnaires of health-related quality of life (HRQOL), Medical Outcomes Study 36-Item Short-Form Health Survey (SF-36), and World Health Organization Quality of Life (WHOQOL)-BREF Taiwan version. The convergent validity was accomplished by a series of Spearman rank correlations. Reliability of the MA II Taiwan version was determined by internal consistency obtained by Cronbach's alpha coefficient and test-retest reliability obtained by intraclass correlation coefficient. RESULTS One hundred subjects with morbid obesity were enrolled to test the MA II Taiwan version convergent validity and internal consistency. Test-retest studies (2 weeks apart) were applied to 30 morbidly obese patients. Satisfactory internal consistency was demonstrated by a Cronbach's alpha coefficient of 0.79. Good test-retest reliability was shown by intraclass correlations ranging from 0.73 to 0.91. The total sum of MA II scores was significantly correlated with all four domains of the WHOQOL-BREF and two major components of SF-36 (all correlations, p < 0.01; range, 0.44-0.64). All six MA II items showed significant correlations with each other (r = 0.34-0.69, p < 0.01), and the total sum of MA II scores was negatively correlated with body mass index (r  = -0.31, p < 0.01), indicating a one-dimensional questionnaire of HRQOL. CONCLUSIONS The MA II Taiwan version is an obesity-specific questionnaire for QOL evaluation with satisfactory reliability and validity. It has the advantages of extensive evaluation for HRQOL, cross-cultural application, rapid completion, high response rates, and an advanced scoring system.