title: Potential cost-effective use of spine radiographs to detect vertebral deformity and select osteopenic post-menopausal women for amino-bisphosphonate therapy.
abstract: Prevalent vertebral deformities are predictive of future clinical fractures independent of bone density. We used a Markov model with eight health states to estimate from the societal perspective the cost-effectiveness of using spine radiographs to identify postmenopausal women age 60 or older with one or more vertebral deformities and then treat them with anti-resorptive drug therapy to prevent fractures. We compared three strategies: 5 years of amino-bisphosphonate (alendronate) therapy for all, 5 years of alendronate therapy for only those with prevalent a radiographic vertebral deformity or no initial alendronate treatment. Lifetime direct medical and indirect costs, quality adjusted life years (QALYs) and incremental cost-effectiveness ratios (ICERs) were tracked. For women with one or more prevalent vertebral deformities, the costs per QALY gained ranged from 5,084 dollars (for an 80 year old with a T-score of -2.4) to 61,192 dollars (for a 60 year old with a T-score of -1.0). For women without prevalent vertebral deformity, the costs per QALY gained ranged from 41,897 dollars (for a 60 year old with a T-score of -2.4) to 166,219 dollars (for an 80 year old with a T-score of -1.0). These results were modestly sensitive to reasonable changes in fracture rates, disutility, discount rates and assumptions about the accuracy of spinal radiographs for detecting vertebral deformity. Assuming a societal willingness to pay per QALY gained of 50,000 dollars, the strategy of performing spine radiographs in post-menopausal osteopenic women with T-scores at or below -1.5 and treating those with 1 or more prevalent vertebral deformities is likely to be cost-effective. However, further research on the accuracy of vertebral deformity ascertainment from routine clinical radiographs and on the efficacy of amino-bisphosphonate drugs for reducing the risk of non-vertebral fractures in osteopenic women is needed to define more precisely the subset of osteopenic post-menopausal women in whom use of spinal radiographs is most cost-effective.
authors.affiliation: Park Nicollet Health Services, Minneapolis, MN, USA. schouj@parknicollet.com
authors.forename: John T
authors.initials: JT
authors.lastname: Schousboe
authors.forename: Kristine E
authors.initials: KE
authors.lastname: Ensrud
authors.forename: John A
authors.initials: JA
authors.lastname: Nyman
authors.forename: Robert L
authors.initials: RL
authors.lastname: Kane
authors.forename: L Joseph
authors.initials: LJ
authors.lastname: Melton
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D019386:Alendronate / Q000191:economics / Q000627:therapeutic use*; D050071:Bone Density Conservation Agents / Q000191:economics / Q000627:therapeutic use*; D003362:Cost-Benefit Analysis / Q000379:methods; D005260:Female; D017048:Health Care Costs; D006801:Humans; D008390:Markov Chains; D008875:Middle Aged; D018803:Models, Economic; D015663:Osteoporosis, Postmenopausal / Q000150:complications / Q000000981:diagnostic imaging* / Q000191:economics; D019057:Quality-Adjusted Life Years; D011859:Radiography; D016103:Spinal Fractures / Q000191:economics / Q000209:etiology / Q000517:prevention & control*; D013131:Spine / Q000002:abnormalities* / Q000000981:diagnostic imaging
chemical_list: D050071:Bone Density Conservation Agents; D019386:Alendronate