European women's preference for osteoporosis treatment: influence of clinical effectiveness and dosing frequency

Objective: To determine participant preference for weekly versus monthly bisphosphonate therapy for osteoporosis after being informed about differences in fracture efficacy. Design: 20-minute, semi-structured, face-to-face or telephone interviews. Two bisphosphonate choices were presented on the basis of block randomization: weekly therapy with proven efficacy to reduce fracture risk at the spine and hip, or monthly therapy with proven efficacy to reduce fracture risk at the spine but not the hip. Subjects: Women from the UK, Germany, France, Spain and Italy, with postmenopausal osteoporosis and aged >= 55 years. Fifty percent were currently taking a weekly bisphosphonate; 50% had no history of taking any bisphosphonate. Measures: An efficacy rating scale and an intention-to-use rating scale were developed for this study. The primary use endpoint was preference for weekly or monthly therapy. Reasons for preference were recorded. Results: A preference was recorded for 1248 women ( 1253 were recruited). More women preferred weekly to monthly therapy ( 82% vs. 18%, respectively; p < 0.001). Among women who preferred weekly therapy, efficacy was the most commonly cited reason ( 65%). Ninety-two percent of the total cohort rated the efficacy of two the weekly therapy as 'excellent/good' versus 38% for monthly ( p < 0.001). Sixty-nine percent intended to use weekly bisphosphonates compared with 34% for monthly ( p < 0.001). Conclusions: When informed about differences in fracture efficacy in weekly and monthly bisphosphonates, a significantly greater proportion ( 82%) of women preferred a weekly bisphosphonate with proven fracture efficacy at the spine and hip over a monthly bisphosphonate with proven fracture efficacy only at the spine.