A cost effectiveness analysis of calcium and vitamin D supplementation,etidronate, and alendronate in the prevention of vertebral fractures in women treated with glucocorticoids

OBJECTIVE: To assess the relative costs and benefits of calcium and vitamin D supplements, cyclic etidronate, or alendronate in the prevention of vertebral fractures for women and with normal bone density and osteopenia who are about to initiate moderate dose glucocorticoid treatment. METHODS: Using a decision analysis model, we evaluated the following patients: 4 hypothetical cohorts: 30-yr-old women with normal lumbar spine (LS) bone mineral density (BMD) (t score = 0), 50-yr-old women with borderline osteopenia (t score = -1), 60-yr-old women with moderate osteopenia (t score = -1.5), and 70-yr-old women with severe osteopenia (t score = -2) treated with a mean prednisone dose of 10 mg/day for one year. The main outcomes included the development of vertebral fractures 10 years after glucocorticoid treatment and at age 80 (life-time risk) and direct and indirect costs. RESULTS: At 10 years, calcium and vitamin D supplements decreased fracture rates by 30-50% at a minimal cost (US$800 or less per vertebral fracture avoided) or at a cost saving compared to no treatment for women with osteopenia (t score -1 to -2). Etidronate and alendronate are most cost effective in women with borderline osteoporosis (t scores of -1.5 and -2) in the 10 year analysis. In the life-time analysis, calcium and vitamin D treatment yielded a cost savings compared to no treatment for all groups with osteopenia. Etidronate decreased fracture rates further in all groups at a cost of less than $2,000 per fracture prevented. Alendronate reduced the fracture risk further at cost of $3,000-7,000 per fracture avoided. CONCLUSION: Calcium and vitamin D supplements and low cost bisphosphonate regimens such as cyclic etidronate decrease the life-time vertebral fracture risk at acceptable costs and should be considered when initiating glucocorticoid treatment for women who do not have osteoporosis.