Validation of the Malay version of the Quality of Life Questionnaire of the European Foundation for Osteoporosis (QUALEFFO-41) in Malaysia

Transcultural adaptation and psychometric properties of the Korean version of the Quality of Life Questionnaire of the European Foundation for Osteoporosis (QUALEFFO-41)

We translated and adapted transculturally the Quality of Life Questionnaire of the European Foundation for Osteoporosis (QUALEFFO-41) for Korean patients. The translated Korean version of QUALEFFO-41 showed satisfactory reliability and validity.

PURPOSE

The aim of this study was to translate the QUALEFFO-41 for Korean patients and then validate the Korean version of QUALEFFO-41.

METHODS

Translation and transcultural adaptation of the QUALEFFO-41 was conducted according to the international recommendations. Ninety-seven patients (mean age, 73.6 years) with osteoporosis were participated in validating the Korean version of QUALEFFO-41. To test reliability, internal consistency was evaluated using Cronbach's alpha coefficient. To test validity, convergent validity was assessed using correlation with the SF-12 and EQ-5D and discriminant validity was assessed using ROC curve analysis.

RESULTS

The English version of QUALEFFO-41 was translated and adapted to Korean without notable discrepancies. The Korean QUALEFFO-41 had good reliability with Cronbach's alpha ranging from 0.733 to 0.942. QUALEFFO-41 had good correlations to SF-12 and EQ-5D. Compared with subjects without history of vertebral fracture (VF), those with history of VF showed significantly worse scores according to QUALEFFO-41, but not according to SF-12 or EQ-5D. ROC curve analysis revealed that the physical function domain of QUALEFFO-41 had significant ability to discriminate between subjects with and without history of VF, while SF-12 or EQ-5D did not.

CONCLUSIONS

The Korean version of QUALEFFO-41 demonstrated relevant internal consistency, convergent validity, and discriminant validity, which can be recommended to evaluate quality of life in Koreans.