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Background: Mechanical thrombectomy has emerged as standard of care in treatment of patients with acute ischemic stroke attributable to large-vessel occlusion. Efforts to reduce the time from symptom onset to treatment initiation remain critically important to improve functional outcomes in patients treated with either intravenous thrombolysis, mechanical thrombectomy, or both. The use of ambulance helicopters in prehospital acute stroke care could potentially reduce symptom onset to treatment time to mechanical thrombectomy. This study aims to optimize the use of ambulance helicopters in prehospital transportation of patients with presumed acute stroke attributable to large-vessel occlusion given economic constraints in health care budget.

Methods: By means of an economic model within a decision-analytical framework, this study evaluates the cost-effectiveness of complementary ambulance helicopters compared with road ambulances only for prehospital acute transportation of patients with presumed stroke and potential eligibility for mechanical thrombectomy, in regard to the number and locations of ambulance helicopters in Sweden.

Results: A single, optimally located complementary ambulance helicopter was cost-effective compared with road ambulances only. The most cost-effective solution in the base-case scenario with the current 8 thrombectomy centers comprised 13 optimally located helicopters. It reduced mean onset to treatment time with intravenous thrombolysis and onset to treatment time with mechanical thrombectomy by 7.9 and 32.1 minutes, respectively, and produced health gains equal to 91 quality-adjusted life-years per year. When the willingness to pay per quality-adjusted life-years gained was set at Euro (EUR) 80 000, the incremental net monetary benefit per patient reached EUR 2240. The solution with 13 optimally located helicopters prevailed as the most cost-effective in the extended scenario analysis with 11 thrombectomy centers, reaching an estimated incremental net monetary benefit per patient at EUR 1754. Furthermore, mean incremental net monetary benefit per patient reached global maximum (EUR 6046) at the geodesic distance of 165.2 km between patient location and the nearest thrombectomy center in the base-case scenario, and at 238.5 km in the extended scenario with an estimated incremental net monetary benefit per patient at EUR 7994.

Conclusion: This study demonstrates the cost-effectiveness of ambulance helicopters as a complementary mode of transportation to road ambulances. The most cost-effective solution of complementary ambulance helicopters comprises 13 optimally located heliports across Sweden.