Cost-effectiveness of Virtual Bone Strength Testing in Osteoporosis Screening Programs for Postmenopausal Women in the United States.

Purpose To investigate whether assessment of bone strength with quantitative computed tomography (CT) in combination with dual-energy x-ray absorptiometry (DXA) is cost-effective as a screening tool for osteoporosis in postmenopausal women. Materials and Methods A state-transition microsimulation model of osteoporosis for postmenopausal women aged 55 years or older was developed with a lifetime horizon and U.S. societal perspective. All model inputs were derived from published literature. Three strategies were compared: no screening, DXA with T score-dependent rescreening intervals, and a combination of DXA and quantitative CT with different intervals (3, 5, and 10 years) at different screening initiation ages (55-65 years). Oral bisphosphonate therapy was started if DXA hip T scores were less than or equal to -2.5, 10-year risk for hip fracture was greater than 3% (World Health Organization Fracture Risk Assessment Tool score, or FRAX), 10-year risk for major osteoporotic fracture was greater than 20% (FRAX), quantitative CT femur bone strength was less than 3000 N, or occurrence of first fracture (eg, hip, vertebral body, wrist). Outcome measures were incremental cost-effectiveness ratios (ICERs) in 2015 U.S. dollars per quality-adjusted life year (QALY) gained and number of fragility fractures. Probabilistic sensitivity analysis was also performed. Results The most cost-effective strategy was combined DXA and quantitative CT screening starting at age 55 with quantitative CT screening every 5 years (ICER, $2000 per QALY). With this strategy, 12.8% of postmenopausal women sustained hip fractures in their remaining life (no screening, 18.7%; DXA screening, 15.8%). The corresponding percentages of vertebral fractures for DXA and quantitative CT with a 5-year interval, was 7.5%; no screening, 11.1%; DXA screening, 9%; for wrist fractures, 14%, 17.8%, and 16.4%, respectively; for other fractures, 22.6%, 30.8%, and 27.3%, respectively. In probabilistic sensitivity analysis, DXA and quantitative CT at age 55 years with quantitative CT screening every 5 years was the best strategy in more than 90% of all 1000 simulations (for thresholds of $50 000 per QALY and $100 000 per QALY). Conclusion Combined assessment of bone strength and bone mineral density is a cost-effective strategy for osteoporosis screening in postmenopausal women and has the potential to prevent a substantial number of fragility fractures. © RSNA, 2017 Online supplemental material is available for this article.

Treatment strategies for patients with low bone mass: the younger postmenopausal female.

Estimating an individual's fracture risk is the most significant factor for determining the need to initiate bone strengthening treatment in the postmenopausal woman. Fracture risk in inversely and most strongly related to an individual's bone mineral density values, but other factors including age, prior fracture history, body mass index, general health, family history of fractures, corticosteroid use, and smoking history also influence the risk of subsequent fractures. Fracture risk assessment tools such as the World Health Organization's FRAX tool and the Study of Osteoporotic Fractures Index provide 10- and 5-year fracture probability estimates, respectively, and using these tools can be particularly helpful in assessing the immediate need to initiate treatment in younger postmenopausal women. Perimenopausal and postmenopausal bone loss averages about 1% per year with more annual bone loss occurring in trabecular than cortical bone and during a normal life span such bone loss can exceed 35% of an individual's bone mass. Younger postmenopausal women with low bone mineral density values, a history of a previous fracture, greater rates of bone loss as measured by bone turnover markers are more likely to need bone strengthening treatment at an earlier age in the postmenopausal period. Treatment measures include adequate amounts of dietary and supplemental calcium and vitamin D, a routine of regular exercises and medications that reduce the rate of new fractures.