[A cost-effectiveness analysis of alendronate compared to placebo in the prevention of hip fracture].

objectiveTo examine if the treatment with alendronate to prevent hip fracture (HF) in female with established osteoporosis is more cost-effectiveness than placebo, and if changes in efficacy, cost and incidence of adverse reactions of the treatment can affect the ratio, and the direction of decision.

designThe study is based on a decision tree model to examine the cost-effectiveness ratio (CE) of alendronate (10 mg/d alendronate, 500 mg/d calcium and 250 IU vitamin D3) versus placebo (500 mg/d calcium and 250 IU vitamin D3). The treatment of 1000 patients with established osteoporosis and its course of events and probabilities during three years of treatment is simulated.

resultsThe efficacy of each alternative is obtained by controlled clinical trials. The considered costs, from the first perspective of the services provider, and expressed in pesetas per year in 1998, are direct health tangibles: pharmacological treatment, HF surgery and treatment of serious adverse reactions (SAR). An analysis of simple univariate sensibility and one of incremental is applied on the efficacy, cost and incidence of adverse reactions to alendronate. The ratio CE of alendronate is 297.879 pesetas/success (patient without fracture and without SAR) and 23.301 pesetas/success for placebo. For the hypothesis of a 100% alendronate efficacy, the ratio CE is 287.217 pesetas/success and without SAR is 297.830 pesetas/success. A cost of 210 pesetas/alendronate box will determine that this alternative is as cost-effective as placebo.

conclusionsThe administration of alendronate to prevent HF on postmenopausal female with established osteoporosis is not the option to take into account. Just a decrease of the cost of alendronate below its crossing value will turn it into a cost-effective alternative.