Optimizing prehospital acute stroke care in the presence of economic constraints

Sammanfattning: Mechanical thrombectomy (MT) has become standard of care for acute anterior circulation ischaemic stroke due to large vessel occlusion since the launch of second-generation stent retrievers for clinical use nearly a decade ago. Up until recently, the treatment was exclusively performed at university hospitals in Sweden. Sundsvall Regional Hospital joined as the eighth treatment facility in late 2023. Scarce resources of healthcare systems across the world hamper the complete implementation of MT in acute stroke care. Hence, efforts to improve patients’ accessibility to and healthcare providers’ utilization of MT remain prioritized. Methods for determining the optimal number and locations of treatment facilities for MT in economically constrained healthcare systems remain unstudied. The optimal number and locations of ambulance helicopters for prehospital transportation of patients with presumed acute stroke too. The aim of the thesis is to solve constrained optimization problems within the framework of cost-effectiveness analysis for prehospital acute stroke care management of patients with AIS.   To fill these knowledge gaps, this thesis takes on an interdisciplinary research approach, and combines health economics, operations research, and medicine to identify cost-effective solutions for location problems with respect to the implementation of MT in the Swedish healthcare system. A comprehensive set of consolidated data based on anonymized, patient-level, nation-wide registry data for a study period of six years underlies analyses. This thesis employs predictive modelling, geographic network analysis, optimization, and decision modelling for economic evaluation within the framework of cost-effectiveness analysis to identify the most cost-effective solutions to implement.    The fitting of predictive generalized linear models to four treatment modalities in acute stroke care for patients with acute ischaemic stroke established the linear associations in absolute effect measures between the modified Rankin Scale score at 90 days post-stroke and the time from symptom onset to treatment start with intravenous thrombolysis only, MT only and intravenous thrombolysis plus MT, respectively. With imposed economic constraints, the analysis identified the optimal number and locations of thrombectomy centres for the Swedish healthcare system. Furthermore, it identified the optimal number and locations of ambulance helicopters too. Finally, it was possible to determine the combination of optimally located thrombectomy centres and ambulance helicopters that comprises the most cost-effective solution to implement into the Swedish stroke system of care.   This thesis demonstrates that economically constrained optimization of thrombectomy centres and ambulance helicopters in acute stroke systems of care comprises highly cost-effective solutions that entail immense health gains in patients with acute ischaemic stroke. Health economics, operational research and medicine can be combined to create a powerful decision-modelling tool in the evaluation of implementation strategies for prehospital acute stroke systems of care.