Measuring quality of life in women with vertebral fractures due to osteoporosis: A comparison of the OQLQ and QUALEFFO

Introduction: Studies comparing the performance of health-related quality o f life instruments in osteoporosis are lacking. We compared the feasibility , validity and reliability of the osteoporosis quality of life questionnair e (OQLQ) and the QUALEFFO (test version) in women with vertebral deformitie s due to osteoporosis. Methods: Three hundred and thirty-eight patients dia gnosed with primary osteoporosis and vertebral deformity and a random sampl e of 304 women from the general population (control group) were recruited. Patients and controls were randomly assigned to receive either the OQLQ or the QUALEFFO, and the SF-36 and EQ-5D. Test-retest reliability was assessed in the patient group. Results: The QUALEFFO had more items with missing da ta and took slightly longer to administer (20.7 vs. 18.7 min). Cronbach's a lpha and intraclass correlation coefficient (ICC) values for OQLQ domains ( alpha: 0.75-0.91; ICC: 0.85-0.93) were slightly higher than for the QUALEFF O (alpha: 0.63-0.90; and ICC: 0.80-0.93). OQLQ and QUALEFFO domain scores c orrelated as expected with SF-36 and EQ-5D domains. Both questionnaires dis criminated between patients and controls though the OQLQ showed slightly be tter discriminant power. Discussion: The superior performance of the OQLQ i n terms of administration time, missing responses, and discriminatory capac ity needs to be weighed against the advantages of using a self-administered instrument such as the QUALEFFO. A full comparison also requires data on s ensitivity to change.