OBJECTIVES: • To estimate numbers of clinical events (strokes, major bleeds, acute myocardial infarctions and deaths) and healthcare costs over a five year period in Ireland following a switch of antithrombotic therapy for atrial fibrillation (AF) from warfarin to dabigatran. METHODS: • A model was built in Microsoft Excel and included an estimate of the number of Irish patients diagnosed with AF and eligible for treatment with dabigatran. • It is assumed that all diagnosed AF patients eligible for oral anticoagulation currently receive warfarin and that all patients switch to dabigatran in Year 1, regardless of International Normalised Ratio (INR) control amongst warfarin patients. • Differences in numbers of clinical events expected to occur based on a patient’s antithrombotic treatment were estimated by applying event rates from literature sources. Costs were estimated from a HSE perspective and included costs of clinical events, disability costs and medication costs. RESULTS: • 28,332 Irish patients are estimated to have been diagnosed with AF and are eligible for dabigatran • Switching these patients from warfarin to dabigatran may avoid: o 657 strokes o 792 major bleeds o 1,437 deaths • By Year 5, cumulative dabigatran drug costs were estimated at €7,670,870. Cost savings due to clinical events avoided amounted to €2,894,743 and savings on disability costs at €5,563,349, giving a total cost saving with dabigatran of €787,223. CONCLUSIONS: Use of dabigatran as compared to warfarin for stroke prevention in AF in the Irish setting may avoid a significant number of clinical events and result in overall cost savings.