Continuing rapid growth of the elderly population of the United States is expected to result in substantial numbers of individuals at risk of osteoporosis. Economically efficient methods of managing osteoporosis will be needed. The goal of this analysis was to identify the level of fracture risk at which therapeutic intervention becomes cost-effective. The analysis was based on estimates of fracture incidence, morbidity, mortality, and cost that are specific to the US. The cost-effectiveness analysis incorporated the cost and health consequences of clinical fractures of the hip, spine, forearm, shoulder, rib, pelvis, and lower leg. The intent was to identify the 10-year probability of hip fracture necessary for osteoporosis treatment to be cost-effective for cohorts defined by age, gender, and race or ethnicity. Costs are represented in 2005 US dollars.
In order to determine the 10-year probability of hip fracture at which treatment became cost-effective, average annual age-specific probabilities for all fractures were multiplied by a relative risk varying from 0 to 10 until the cost of treatment, compared to no intervention, was $60,000 per quality-adjusted life year gained. Osteoporosis treatment proved cost-effective when the 10-year probability of hip fracture reached about 3%. Although the relative risk at which treatment became cost-effective varied substantially by gender and race/ethnicity, the absolute 10-year probability of hip fracture at which intervention became cost-effective was similar across racial/ethnic groups. It tended to be slightly higher for men than for women. When bone fracture was assumed to have an adverse lifetime influence on health-related quality of life, the intervention threshold for women less than 70 years of age declined to about 1.5%.