Association between generic and disease-specific quality of life questionnaires and mobility and balance among women with osteoporosis and vertebral fractures
BACKGROUND AND AIMS: The aims of this study were to assess correlations between two health-related quality of life (HRQOL) measurements, the Quality of Life Questionnaire issued by the European Foundation for Osteoporosis (QUALEFFO- 41) and the total score of The General Health Questionnaire (GHQ-20) in a population of women living at home with well-established osteoporosis and at least one vertebral fracture, as well as the internal consistency and floor and ceiling effects of these measurements. Also examined were the mean values of these measurements, to ascertain whether they were significantly different for the group consisting of 75% of the women with the best performance on mobility and balance, compared with the other participants. METHODS: Across-sectional study of 89 women aged 60 years or more, evaluated by QUALEFFO-41 (consisting of one total score and five section scores), GHQ-20 (one total score), maximum speed and Functional Reach (FR). RESULTS: Cronbach's alpha coefficient for measurements of HRQOL ranged from 0.61 to 0.92. Significant correlations between 'QUALEFFO- 41: total score' and 'GHQ-20: total score' were 0.49, and between 'GHQ-20: total score' and section scores of 'QUALEFFO-41' 0.28-0.63. Those in the 75% group with the highest maximum walking speed or longest distance on FR reported significantly better disease-specific HRQOL than the others, with poorer results on these tests. CONCLUSIONS: Disease-specific and generic HRQOL instruments are not redundant when applied together, and the disease-specific 'QUALEFFO-41' and generic GHQ-20 measure different aspects of HRQOL.