Alendronate may not be cost-effective in women with osteopenia

New research shows that alendronate is not cost-effective in treating postmenopausal women with low bone mass. The findings suggest that drug therapy may not be advisable for women with femoral-neck T-scores better than -2.5 and no history of clinical fractures or other bone-mineral-density-independent risk factors for fractures. “These results are probably generalizable to risedronate and raloxifene,” comment the investigators, led by Dr John Schousboe (Park Nicollet Clinic, Minneapolis, MN). But they argue they likely do not apply to estrogen replacement therapywhich is often less expensive than alendronate.

Schousboe and colleagues point out that current treatment guidelines recommend drug therapy to prevent fractures for some postmenopausal women who have low bone mass or osteopenia but who do not have osteoporosis or a history of fractures. In the present study, published in the May 3, 2005 issue of the Annals of Internal Medicine, the research team sought to estimate the societal costs and health benefits of this recommendation. They chose to look at alendronate specifically because it is among the most commonly prescribed antiresorptive agents.In an accompanying editorial, Dr Michael McClung (Oregon Osteoporosis Center, Portland) says that while Schousboe and colleagues clearly demonstrate that alendronate therapy in postmenopausal women selected solely on the basis of low bone density is not cost-effective, some women are at clinically significant fracture risk where therapy may be justified. He cites the elderly, those beginning glucocorticoid therapy, or those discontinuing estrogen therapy as examples of women who are expected to experience rapid short-term bone loss who may be candidates for therapy even if they do not have osteoporosis.McClung argues that the diagnostic category of osteopenia does not serve the clinical community well. “It is time to abandon the diagnosis of osteopenia based on bone-mineral-density values and give the term back to radiologists to describe decreased bone mineralization on radiographs.” He adds that while bone-density measurement remains an important tool in assessing skeletal health, the determinants of fracture are much more complex and interesting than simply the T-score. “The objective of using osteoporosis drugs is to prevent fractures. This can be accomplished only by treating patients who are likely to have a fracture, not by simply treating T-scores.”Cost-effectiveness may be even less favorable if drug compliance declinesIn the Schousboe study, the investigators collected data from population-based studies of age-specific fracture rates and costs as well as estimates of disutility after fractures and from the Fracture Intervention Trial of alendronate vs placebo to prevent fractures. They looked at postmenopausal women aged 55 to 75 years of age with femoral-neck T-scores between -1.5 and -2.4. They used a Markov cost-utility model that contained 8 health states and compared 5 years of treatment with alendronate with no drug therapy. The health states they used were no fracture, post-distal forearm fracture, post-clinical vertebral fracture, post-radiographic vertebral fracture, post-hip fracture, post-other fractures, post-hip and vertebral fracture, and death.The group found that for women with no additional fracture risk factors, the cost per quality-adjusted life-year gained ranged from $70 000 to $332 000, depending on age and femoral-neck bone density. “Alendronate is not cost-effective in osteopenic postmenopausal women who have not had any clinical fractures, unless substantial risk from additional bone-mineral-density-independent fracture risk factors is present,” the researchers write. “Moreover, the cost-effectiveness may be less favorable if drug adherence decreases substantially over time, which 1 study of once-weekly alendronate therapy has documented.”Conclusions could be reconsidered if drug prices lowered, for exampleThe authors say these conclusions should be reassessed if the cost of drugs is significantly lowered, if drug therapy is shown to reduce the risk of nonvertebral fractures, or if fracture-reduction benefit persists longer than 10 years after a 5-year treatment course.Schousboe and colleagues point out that their results are generalizable only to the postmenopausal white female population of the US. In his accompanying editorial, McClung notes that despite the study’s limitations, the results are consistent with the cost-effectiveness analysis reported by the National Osteoporosis Foundation. He adds, “The analyses appropriately included the costs of all fragility fractures, not just hip fractures, and addressed the sensitivity of the cost-effectiveness threshold to treatment adherence and drug costs.”McClung explains that while cost-effectiveness is an important consideration for health payers and policy makers, it is a concept that rarely resonates with patients, who usually make decisions about treatment on the basis of perception of benefit. “Many are willing to pay for treatments that will protect them from medical consequences, if the risk associated with treatment is minimal,” he writes. “What is often missing from the discussion with patients about osteoporosis treatment is an appreciation of their actual risk for fracture.” McClung points out that patients respond to discussions of risk reduction more readily than they do to issues of cost. He notes that fracture risk depends not only on the bone-density value but on other independent risk factors such as age, previous fracture, and the tendency to fall.(Source: Joint & Bone: May 2005.)