OBJECTIVES: Antiplatelet therapy, following acute stroke, has been shown to have preventative efficacy against serious vascular events, including: recurrent stroke, transient ischaemic attack and myocardial infarction. We used a Markov model approach to consider the relative cost-effectiveness of alternative antiplatelet therapies compared to standard low-dose aspirin.
METHODS: An existing Markov model was updated with UK-specific data on expected health care resource usage and unit costs, and was used to consider levels of recurrent stroke-related events, and their associated cost implications, over periods of time of up to 25-years after an acute stroke event. Underlying risks were derived from the placebo-control arm of the ESPS-2 study (Years 1-2 of the model), and the community-based Oxford Community Stroke Project (Years 3-5 of the model). Beyond Year 5, risks were based on an age-matched cohort from the OCSP data. Relative risks for active treatments were derived from the ESPS-2 study for both Asasantin Retard and low-dose aspirin, and the CAPRIE study for clopidogrel. Estimates of expected resource usage were based on feedback on a structured questionnaire survey of UK-based clinicians.
RESULTS: When compared to low-dose aspirin, Asasantin Retard provided additional benefits (29 avoided recurrent strokes per 1,000 treated patients over a 5-year period) for an additional cost of approximately £66,000 (a cost per avoided stroke of £2,249). A probabilistic Monte carlo sensitivity analysis based on background placebo-level risks, relative risk for Asasantin Retard, costs of an acute stroke and costs of long-term care suggested that a 95% likelihood of the cost per avoided stroke value falling below £14,000. Asasantin Retard had lower treatment-related cost and avoided more recurrent stroke events than clopidogrel in the modelled 5-year analysis.
CONCLUSIONS: Our modelled analysis suggests that Asasantin Retard is a cost-effective treatment compared to standard low-dose aspirin in avoiding acute recurrent stroke-related events.
