Optimising regional organisation of endovascular thrombectomy for ischaemic stroke reusing a simulation model.

Abstract

This study assessed whether a previously developed Monte Carlo simulation model can be reused for evaluating various strategies to minimise time-to-treatment in southwest Netherlands for endovascular thrombectomy (EVT) in patients who had an ischaemic stroke. Reuse of a previously developed simulation model to simulate various strategies in another region, using prospectively collected data from stroke centres and retrospective data from emergency medical services. Data from 509 patients who had an ischaemic stroke (≥18 years) treated with EVT (2014-2018) were used. Input for the simulation model reuse included distributions of observed time delays along the acute stroke pathway. Validation of the baseline models was based on face validity and statistical measures (patient data vs model output) using the Assessment of the Validation Status of Health Economic decision models tool. We simulated strategies for a subregion: interhospital patient transfer by helicopter, transport of the neurointerventionalist to the primary stroke centre ('drive-the-doctor'), interhospital patient transfer to a thrombectomy-capable stroke centre (TSC) outside the region and prehospital triage using the Rapid Arterial Occlusion Evaluation (RACE) scale. Onset-to-groin time was the outcome. Reuse of the original simulation model was obtained by minimal effort, implying limited adaptation. Compared with the baseline model, interhospital patient transfer by helicopter or to a TSC outside the region and prehospital routing using the RACE scale reduced mean onset-to-groin time by 16, 13 and 39 min, respectively (95% CrI for all: equal to the point estimate). 'Drive the doctor' reduced mean onset-to-groin time by 27 (car), 49 (ambulance) or 58 min (helicopter), each with a 95% CrI equal to the point estimate. The original simulation model can be applied to different regions in the Netherlands. Strategies tested within the subregion resulted in promising results of 'drive the doctor' and prehospital patient routing using the RACE scale.