Cost-effectiveness of risedronate for the treatment of osteoporosis and prevention of fractures in postmenopausal women.

Randomized, double-blind, controlled studies have shown that treatment with risedronate reduces the risk of vertebral fracture in postmenopausal women with established vertebral osteoporosis. They also show that the drug decreases the risk of non-vertebral fractures in women with osteoporosis. The aim of this study was to investigate the cost-effectiveness of risedronate in postmenopausal women with osteoporosis. A Markov model was applied to a UK setting. Treatment effects were computed by meta-analysis of randomized, controlled trials and given over 5 years to subjects aged between 60 and 80 years. Quality-adjusted life years (QALYs) and life years gained were used as outcome measures. Intervention with risedronate was cost-effective in women aged 60 years and older. Cost savings were also found for postmenopausal women aged 70 years and older with established vertebral osteoporosis (a prior spine fracture and BMD T-score < or =-2.5 SD). This treatment was cost-effective for women aged 65 years and older who had a prior vertebral fracture and a BMD T-score at the threshold of osteoporosis ( T-score=-2.5 SD), and in women with a T-score < or =-2.5 SD, but without a prior vertebral fracture. In women aged 60-80 years and at the threshold of osteoporosis ( T-score=-2.5 SD) but without a prior vertebral fracture, treatment exceeded the threshold for cost-effectiveness. However, if an additional, independent risk factor was assumed (e.g., corticosteroid use) treatment became cost-effective.