Osteoporosis is a large and growing disease with significant health consequences. Based on an evaluation of clinical evidence, the German osteology umbrella organization DVO (Dachverband Osteologie deutschsprachiger wissenschaftlicher Fachgesellschaften) published guidelines in March 2003 for the diagnosis and treatment of
osteoporosis. For prevention of fractures in women with postmenopausal and
senile osteoporosis, these guidelines recommend three treatment options as first-line
therapy:
risedronate,
alendronate and
raloxifene. No evidence is currently available for the reduction of
hip fractures by
raloxifene. Only
risedronate and
alendronate, therefore, are recommended for prevention of
hip fractures. Information on the cost-effectiveness of preventing and treating
osteoporosis may support decision makers in more efficient allocation of resources. Accordingly, the objective of this study is the comparative assessment of the cost-effectiveness of
risedronate,
alendronate and
raloxifene for patient populations in Germany at high risk of
osteoporotic fracture due to
low bone mineral density (BMD) (i.e., T-score < -2.5) and resulting from a history of at least one previous vertebral fracture, as compared to osteoporotic patients with no treatment. Target variables for the economic comparison are costs per hip fracture avoided and costs per quality-adjusted life year (QALY) gained.
Hip fractures are the most costly and best-documented complication of
osteoporosis. A cost-effectiveness analysis was therefore conducted, using as criteria for evaluating intervention the incremental cost per hip fracture avoided and the cost per QALY gained. We used a fracture-incidence-based Markov model of
osteoporosis, with analysis of patients' transition across outcome states over time (e.g., fracture, healthy, dead). Base-case analysis was conducted on a cohort of 1,000 women aged 70 with low spine BMD and prevalent vertebral fracture, over 3 years of treatment with
risedronate,
alendronate or
raloxifene, and with application of a 10-year analytic time horizon. Model inputs included hip and vertebral fracture incidence rates; relative risk of fracture given low BMD and prevalent vertebral fracture, fracture cost, treatment prices/day (
risedronate: 35 mg, 1.76 euro;
alendronate: 70 mg, 1.82 euro;
raloxifene: 60 mg, 1.82 euro); health utility; and efficacy in terms of relative-risk reduction of fracture of the hip (60%
risedronate; 51%
alendronate; not significant
raloxifene) and vertebrae (49%
risedronate; 47%
alendronate; 30%
raloxifene). A 5% discount rate was applied to cost and outcomes. In the base case, treatment with
risedronate reduces costs from the social insurance perspective with respect to both endpoints: i.e., costs per averted hip fracture and QALY. Over the 3-year treatment period and 10-year observation, furthermore,
risedronate proved superior to
alendronate and
raloxifene (i.e.,
risedronate was less expensive and more effective). From the perspective of statutory health insurance, the cost per averted hip fracture is 37,348 euro for
risedronate and 48,349 euro for
alendronate (costs for
raloxifene were not calculated due to a nonsignificant effect on prevention of
hip fractures); and cost per QALY gained is 32,092 euro for
risedronate, in comparison to patients in Germany with no
therapy (
alendronate 41,302 euro;
raloxifene 1,247,119 euro). This cost-effectiveness analysis gives evidence that
bisphosphonates are cost effective. Under consideration of current prices and the published clinical evidence,
risedronate dominates the comparison of DVO-recommended drugs.