Optimal provision of emergency stroke care is challenging because of the multiprofessional involvement, complex clinical pathways and limited time windows for effective treatment, but further gains are possible by improving the delivery of thrombolysis and by implementing the routine provision of IAT. The Promoting Effective And Rapid Stroke Care (PEARS) programme has increased our understanding of how care can be improved both within and across services in ways that are likely to be acceptable to professionals, services and the public.
In 2018/19, IAT was performed on only 1.4% of stroke admissions nationally.6 Although rates continue to increase annually, the provision of IAT lags significantly behind thrombolysis, with marked regional variations. The key for successful NHS implementation of IAT is to take a whole-pathway approach, including ambulance call, initial assessment, initial thrombolysis, imaging, transfer for IAT procedure as appropriate and subsequent repatriation to local rehabilitation services if required. Across the programme, we addressed the optimal means of delivering stroke reperfusion therapies and improving patient outcomes and/or improving cost-effectiveness of services from initial paramedic contact and a thrombolysis treatment decision (WP1) through to selection, routes and transfer mechanisms for IAT (WP2). It has recently been suggested that paramedics could also include thrombectomy eligibility in their routine assessment,98 and there is at least one ongoing trial of paramedic-initiated identification of patients with LAO symptoms,99 both of which could lead to pre-hospital redirection to a CSC. If this were to happen on a large scale, with corresponding movement of specialist resources to hubs to match the growth in central activity, the PASTA intervention might be valuable in the remaining peripheral smaller HASUs. These would then receive only smaller volumes of patients suitable for thrombolysis, but the enhanced paramedic information collection and communication could help to promote good-quality clinical decisions, despite a reduction in local expertise.
Work package 1 highlighted the importance of evaluating a complex intervention (an enhanced paramedic assessment) using a pragmatic RCT design, as the result was not consistent with the previous positive evaluations of pre-hospital stroke interventions.15,16,41 As the PASTA pathway was associated with lower thrombolysis rates but more dominant cost-effectiveness at hospitals with less specialist availability, the structured information collection and communication components of the intervention may have led to better-informed non-specialist treatment decisions. This is a novel hypothesis regarding clinician behaviour under specific circumstances and requires further evaluation, but is consistent with wider evidence that care delivery is improved by structured handovers and checklists. As most IAT patients also initially receive thrombolysis, the PASTA intervention has direct relevance to the delivery of this more complex emergency care pathway defined during WP2. As IAT becomes more available, it would be logical to evaluate whether or not further enhancement of pre-hospital information collection and communication can also facilitate this treatment decision, especially in the absence of a portable diagnostic test.
As might be expected from earlier publications,23,24,62,63 the WP2 systematic review and TSA60 confirmed that IAT for acute ischaemic stroke is both a highly effective and safe treatment for up to 12% of UK stroke admissions,74 which is also unequivocally cost-effective.84 The magnitude of UK costs per treatment is similar to that described in other settings with greater volumes. These findings have had a significant impact on NHS England policy and commissioning guidance, with initial implementation at existing regional neuroscience/CSCs. When we modelled an increase from 24 to 30 CSCs to provide more equitable access to IAT, there was a return on capital investment of £8M over 5 years because of the additional volume and speed of treatment. In the absence of an acceptable pre-hospital selective redirection protocol or technology, a mixed model of Stroke Units and Thrombectomy Centres (with ‘drip and ship’ transfers when required) remains the only viable option for thrombectomy delivery currently. For the furthest (primary) HASU from the CSC, air ambulance secondary transfer for thrombectomy provides a viable cost-effective option if a 45-minute reduction in journey time is achieved compared with ground-based ambulance transport. Public views generally showed support for scenarios where additional travel time was needed to access emergency stroke treatments.
To our knowledge, ITEMS is the first online economic stroke modelling tool designed to support commissioning decisions. Being web based, it will be updated as new evidence and data emerge to promote maximal cost-effectiveness under different geographical and system conditions. Presentation of configurable service options based on region-specific information will promote changes to help realise the The NHS Long Term Plan96 goal of a 10-fold increase in the proportion of patients who receive IAT by 2022.