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

Abstract

Purpose: To assess the validity and reliability of the Malay version of the Quality of Life (QOL) Questionnaire of the European Foundation for Osteoporosis (QUALEFFO-41) in Malaysia.

Methods: The QUALEFFO-41 was translated from English to Malay and administered to 215 post-menopausal osteoporotic women ≥50 years who could understand Malay, at baseline and 4 weeks. The SF-36 was administered at baseline to assess convergent validity. To assess discriminative validity, patients with and without back pain were recruited.

Results: Confirmatory factor analysis showed that the QUALEFFO-41 had five domains. Good internal consistency was seen in all domains (0.752-0.925) except for the social activity domain (0.692). Test-retest reliability showed adequate correlation for all items (0.752-0.964, p < 0.001). Patients with back pain had significantly worse QOL compared with those without (back pain = 42.2 ± 10.9, no back pain = 33.3 ± 8.9; p < 0.001). The total QUALEFFO-41 score and the SF-36 physical and mental composite scores were significantly correlated (-0.636 and -0.529, p < 0.001, respectively).

Conclusions: The Malay version of the QUALEFFO-41 was found to be a reliable and valid instrument to evaluate the QOL of osteoporotic patients in Malaysia. To enable the QUALEFFO-41 to be used in a multiracial population, further studies should look into validating other versions of the QUALEFFO-41 in Malaysia.