National implementation of reperfusion for acute ischaemic stroke in England: How should services be configured? A modelling study

Abstract

Objectives To guide policy when planning thrombolysis (IVT) and thrombectomy (MT) services for acute stroke in England, focussing on the choice between ‘mothership’ (direct conveyance to an MT centre) and ‘drip-and-ship’ (secondary transfer) provision and the impact of bypassing local acute stroke centres. Design Outcome-based modelling study. Setting 107 acute stroke centres in England, 24 of which provide IVT and MT (IVT/MT centres) and 83 provide only IVT (IVT-only units). Participants 242,874 emergency admissions with acute stroke over 3 years (2015–2017). Intervention Reperfusion delivered by drip-and-ship, mothership or ‘hybrid’ models; impact of additional travel time to directly access an IVT/MT centre by bypassing a more local IVT-only unit; effect of pre-hospital selection for large artery occlusion (LAO). Main outcome measures Population benefit from reperfusion, time to IVT and MT, admission numbers to IVT-only units and IVT/MT centres. Results Without pre-hospital selection for LAO, 94% of the population of England live in areas where the greatest clinical benefit, assuming unknown patient status, accrues from direct conveyance to an IVT/MT centre. However, this policy produces unsustainable admission numbers at these centres, with 78 out of 83 IVT-only units receiving fewer than 300 admissions per year (compared to 3 with drip-and-ship). Implementing a maximum permitted additional travel time to bypass an IVT-only unit, using a pre-hospital test for LAO, and selecting patients based on stroke onset time, all help to mitigate the destabilising effect but there is still some significant disruption to admission numbers, and improved selection of patients suitable for MT selectively reduces the number of patients who would receive IVT at IVT-only centres, challenging the sustainability of IVT expertise in IVT-only centres. Conclusions Implementation of reperfusion for acute stroke based solely on achieving the maximum population benefit potentially leads to destabilisation of the emergency stroke care system. Careful planning is required to create a sustainable system, and modelling may be used to help planners maximise benefit from reperfusion while creating a sustainable emergency stroke care system.

Prehospital stroke management and mobile stroke units

“…However, studies have shown that for patients with LVO, secondary transfers from a PSC to a CSC for specialized stroke treatment are associated with detrimental delays and, thus, with a pronounced increase in infarct size as an indicator of harm [7]. In search of the optimal referral strategy, a modelling study of 242 874 emergency admissions in England showed that most of the inhabitants of England would gain the greatest clinical benefit from direct conveyance to a stroke centre capable of administering IAT, although the study also discussed the real-life feasibility of such an approach given the potential destabilization of the EMS system [8]. Another modelling study focusing on healthcare economics concluded that the ‘drip and ship’ approach may have a slight advantage over the ‘mothership’ approach in regard to expected costs [9].…”

Advances in Stroke: A Focus on Health Policy Literature From 2022

“…14 Examination of almost 250 000 acute stroke admissions over 3 years in England found bypassing local stroke centers for direct transport to a thrombectomy center could challenge the sustainability of intravenous thrombolysis expertise in smaller centers and volume at larger hospitals. 15 An acute stroke care quality improvement program with hospital bypass to reduce intravenous thrombolysis treatment delays was found to be feasible and effective in China, 16 and a regional study in Canada determined that hospital bypass was more cost-effective than using transfer protocols. 17 Treatment models independent of transport protocols that leveraged endovascular therapy in Thailand 18,19 and Greece 20 were determined to be cost-effective.…”