Economic assessment of the secondary prevention of ischaemic stroke with dipyridamole plus aspirin (Aggrenox®/Asasantin®) in France

Objective: To assess the cost effectiveness of aspirin 25mg plus dipyridamole 200mg twice daily in the secondary prevention of ischaemic stroke, according to the French social security perspective, using efficacy data from the second European Stroke Prevention Study (ESPS-2). The ESPS-2 was a double-blind, placebo-con trolled clinical trial which assessed the efficacy of four secondary prevention strategies: (i) placebo; (ii) aspirin (acetylsalicylic acid) 25mg twice daily; (iii) dipyridamole 200mg twice daily; and (iv) aspirin 25mg plus dipyridamole 200mg twice daily. Method: We performed a cost-effectiveness analysis with Monte Carlo simulations to compute confidence intervals. We combined data from various sources including the Dijon Stroke Registry, Institut National de la Statistique et des Eludes Economiques, Etude du Co (u) over capt de l'Infarctus Cerebral (Study of the Cost of Cerebral Infarction [ECIC]) study and the ESPS-2 trial. Results: According to our findings, a preventive strategy with aspirin 25mg plus dipyridamole 200mg twice daily is associated with net benefits per avoided stroke recurrence amounting to $US23 932 (95% CI -$US32 609, $US35 772) compared with aspirin 25mg twice daily alone, and $US31 555 (95% CI $US4921, $US74 515) compared with dipyridamole alone (1997 values). Sensitivity analysis demonstrated that dipyridamole plus aspirin was still cost effective when the average cost of adverse effects per episode (ignored in the original estimation of the cost-effectiveness ratios due to a lack of data) was assumed to be $US8600 (50 000 French francs); this cost is unlikely as most of the adverse effects associated with aspirin plus dipyridamole are only slight to moderate in severity. Conclusions: In the secondary prevention of stroke in France, this study suggests, given its underlying assumptions and data, that aspirin 25mg plus dipyridamole 200mg twice daily is likely to be a cost-effective strategy from the social security perspective, when compared with other relevant strategies that were evaluated in the ESPS-2 trial.