The cost effectiveness of bisphosphonates for the prevention and treatment of osteoporosis: a structured review of the literature.

Osteoporotic fragility fractures constitute a significant public health concern. The lifetime risk of any osteoporotic fracture is very high (40-50% in women and 13-22% in men). Fractures are associated with significant mortality and morbidity and represent a substantial economic burden to society. Bisphosphonates (alendronate, etidronate, risedronate and ibandronate) are indicated for the treatment and prevention of osteoporosis but are costly compared with other treatments, such as vitamin D and calcium. Our search identified 23 studies evaluating the cost effectiveness of bisphosphonate therapy for the treatment and prevention of fragility fractures; these studies were from five geographical areas and employed a variety of comparators and assumptions. We identified 11 studies investigating bisphosphonates in women with low bone mineral density (BMD) [T-score >2.5 standard deviations {SDs} below normal {mean} peak values for young adults] and previous fractures, five studies investigating bisphosphonates in women with low BMD and no previous fracture, one study of bisphosphonates in women with osteopenia, five studies involving screening and two studies of bisphosphonates in special populations (women initiating corticosteroid treatment and men). In women with low BMD and previous fractures, bisphosphonate therapy was most cost effective in populations aged > or =70 years and was unlikely to be cost effective in populations aged < or =50 years. There was uncertainty concerning the cost effectiveness of bisphosphonates in such populations aged 60-69 years. In women with low BMD without previous fractures, treatment with alendronate or risedronate appeared to be cost effective across countries (UK, US, Denmark), but there was some uncertainty about the cost effectiveness of etidronate in patients in the highest age groups. Identifying risk factors for fractures through means such as spine radiographs to detect vertebral deformities improves the cost effectiveness of treatment. In women with osteopenia, alendronate therapy may be cost effective in women with a T-score of -2.4SD in the US. Screening for low BMD and treatment with alendronate or etidronate appears to be cost effective in postmenopausal women in general and in women with rheumatoid arthritis initiating corticosteroid therapy. Alendronate therapy without screening was also shown to be potentially cost effective in certain at-risk male populations, as well as in women initiating corticosteroid therapy after the age of 40 years. Decision makers in the US, UK and Sweden should consider funding the use of bisphosphonates for the prevention and treatment of osteoporosis in women aged >70 years, particularly if they have other risk factors for fracture. Further studies are required to make more definitive conclusions in other countries and patient populations. Screening strategies for low BMD followed by bisphosphonate treatment should also be considered in the general female population aged >65 years in the UK and US and in patients with rheumatoid arthritis initiating corticosteroid therapy.