Psychometric properties of the osteoporosis assessment questionnaire (OPAQ) 2.0: results from the multiple outcomes of raloxifene evaluation (MORE) study

BACKGROUND We explored psychometric properties of the Osteoporosis Assessment Questionnaire 2.0 in terms of reliability, validity, and responsiveness with generic, clinical, demographic, and preference-based data collected from a population of postmenopausal women with osteoporosis. METHODS The Multiple Outcomes of Raloxifene Evaluation study was a randomized, placebo-controlled, multinational clinical trial evaluating efficacy and safety of raloxifene. The Osteoporosis Assessment Questionnaire 2.0, a generic quality of life measure (Nottingham Health Profile), and a preference-based measure (Health Utilities Index) were administered at baseline and annually. Psychometric properties of the 14 Osteoporosis Assessment Questionnaire 2.0 domains were evaluated by standard statistical techniques. RESULTS This study included a subset of 1477 women from the Multiple Outcomes of Raloxifene Evaluation study population completing the questionnaires. Mean (standard deviation) age was 68.4 (6.8) years. Prevalent vertebral fractures were found in 70% (n =1038) of women. Internal consistency was >0.7 in 9 Osteoporosis Assessment Questionnaire 2.0 domains. Correlations were moderate and significant for similar Osteoporosis Assessment Questionnaire 2.0 domain scores, Nottingham Health Profile domains, and Health Utilities Index scores. All but 2 Osteoporosis Assessment Questionnaire 2.0 domains distinguished between patients with or without prevalent vertebral fractures and detected worsening with increased number of vertebral fractures. Women with ≥ 1 incident vertebral fracture generally had a greater worsening in Osteoporosis Assessment Questionnaire 2.0 scores (excluding social activity and support of family and friends) from baseline to study endpoint compared with women without incident vertebral fractures. CONCLUSIONS Most domains in the Osteoporosis Assessment Questionnaire 2.0 demonstrated robust psychometric properties; however, several domains not showing these criteria may need to be reassessed and removed for a potentially shorter and validated version of the Osteoporosis Assessment Questionnaire.