[Incremental cost-effectiveness of dipyridamole + acetylsalicylic acid in secondary prevention of ischemic noncardioembolic stroke]

Abstract

Background and purpose: The aim of secondary prevention in stroke is to avoid restrokes. The current standard treatment in Germany is a lifelong therapy with low-dose acetylsalicylic acid (ASA). As the incidence of restrokes remains relatively high from a health-care payer's perspective, the question arises, whether the combination of dipyridamole + acetylsalicylic acid (Dip + ASA) is cost-effective in comparison with a therapy based on ASA only.

Methods: A decision-analytic cross-sectional epidemiologic steady-state model of the German population compares the effects of two strategies of secondary prevention with Dip + ASA (12 months vs. open end) and with ASA monotherapy.

Results: The model predicts the following estimates: the annual incidence of initial ischemic strokes in Germany is estimated at 130,000 plus an extra 34,000 restrokes (base year 2005). Additionally, there are 580,000 people that experienced a stroke > 12 months earlier, of whom 135,000 had a restroke. Every year, nearly 89,000 Germans die of the consequences of an ischemic stroke. If Dip + ASA would have been the standard therapy in secondary prevention of ischemic stroke, an additional 7,500 persons could have been saved in 2005. Statutory health insurance would have to spend 33,000 Euro for every additional life year gained with Dip + ASA as secondary prevention strategy. If secondary prevention with Dip + ASA would be limited to the first 12 months after an initial stroke, which is the time of the highest risk for a restroke, the incremental cost-effectiveness ratio is about 7,000 Euro per life year gained. The results proved to be robust in sensitivity analyses.

Conclusion: Secondary prevention with Dip + ASA is cost-effective in comparison to treatment with ASA in monotherapy, because its incremental cost-effectiveness ratio is within common ranges of social willingness to pay. From the standpoint of the patient as well as the health-care payer, focusing on the first 12 months after the initial incident for intensified preventive drug treatment with Dip + ASA should be valuable from a medical as well as a health-economic perspective.