The impact of fewer hip fractures with risedronate versus alendronate in the first year of treatment: modeled German cost-effectiveness analysis.

Background: The Risedronate and Alendronate (REAL) cohort study provides unique comparative effectiveness data for real world bisphosphonate treatment of osteoporosis.

Objective: The objective of this analysis was to assess the cost-effectiveness of risedronate compared to generic alendronate in Germany applying the REAL effectiveness data.

Materials And Methods: A validated Markov model of osteoporosis was populated with REAL effectiveness data and German epidemiological, cost, and utility data. To estimate the impact of therapy on hip fractures, costs, and quality adjusted life years (QALYs), the analysis included women>or=65 years, treated with risedronate or alendronate and followed for 4 additional years. Country-specific data included population mortality, fracture costs, and annual drug costs, using a German social insurance perspective. Costs and outcomes were discounted at 3%. A differential hip fracture relative risk reduction of 43% was applied to risedronate vs. alendronate.

Results: The model predicted that treatment with risedronate would result in fewer hip fractures and more QALYs at a reduced cost (savings of euro278 per treated woman) compared to treatment with generic alendronate. Sensitivity analysis assuming 2 years of treatment and equivalence of effect after 1 year show cost savings as well (euro106 per treated woman).

Discussion: Whereas previous economic evaluations involving bisphosphonates have mainly relied on efficacy data from noncomparative clinical trials, this study's strength is in the use of comparative effectiveness data from one data source. The magnitude of the cost savings observed were sensitive to alternative assumptions regarding treatment duration, therapy discontinuation and cost of generic alendronate.

Conclusions: Based on "real world" data the analysis supports the first line use of risedronate for the treatment of osteoporotic women in Germany.