The reliability and validity of the Turkish version of Quality of Life Questionnaire of the European Foundation for Osteoporosis (QUALEFFO)

Abstract

The purpose of this study was to investigate the reliability and validity of the Turkish version of Quality of Life Questionnaire of the European Foundation for Osteoporosis (QUALEFFO). The patient group included 43 females aged between 55 and 78 years with vertebral fractures due to osteoporosis. The control group consisted of 43 healthy female volunteers whose ages matched those of the patients. All of the participants were evaluated using both QUALEFFO and SF-36. In the reliability studies, internal consistency within the domain of QUALEFFO was generally good, with Cronbach's alpha values ranging between 0.70 and 0.96. Convergent and discriminant validity rates of domains were both found to be between 89% and 100%. Significant correlations existed between scores of similar domains of QUALEFFO and the SF-36, especially for pain, physical function, social function and general health perception. The receiver operating characteristic (ROC) curve analysis of QUALEFFO and the SF-36 indicated that all five domains in each questionnaire were significantly predictive of vertebral fractures. However, when comparing similar domains of the two questionnaires, the social function domain of QUALEFFO demonstrated a significantly better performance. In conclusion, the Turkish version of QUALEFFO was found to be reliable and valid in the evaluation of patients with vertebral fractures due to osteoporosis. Our study also suggests that the patients with vertebral fractures due to osteoporosis have impairment in quality of life.