Is prehospital treatment of acute stroke too expensive? An economic evaluation based on the first trial

Mobile stroke units services in Germany: A cost-effectiveness modeling perspective on catchment zones, operating modes, and staffing

BACKGROUND AND PURPOSE

Investigating the cost-effectiveness of future mobile stroke unit (MSU) services with respect to local idiosyncrasies is essential for enabling large-scale implementation of MSU services. The aim of this study was to assess the cost-effectiveness for varying urban German settings and modes of operation.

METHODS

Costs of different operating times together with different personnel configurations were simulated. Different possible catchment zones, ischemic stroke incidence, circadian distribution, rates of alternative diagnoses, as well as missed cases were incorporated to model case coverage and patient numbers. Based on internationally reported clinical outcomes of MSUs, a 5-year Markov model was applied to analyze the cost-effectiveness for the different program setups.

RESULTS

Compared with standard stroke care, MSUs achieved an additional 0.06 quality-adjusted life years (QALYs) over a 5-year time horizon. Assuming a catchment zone of 750,000 inhabitants and 8 h/7 day operation resulted in an incremental cost-effectiveness ratio (ICER) of €37,182 per QALY from a societal perspective and €45,104 per QALY from a healthcare perspective. Lower ICERs were possible when coverage was expanded to 16 h service on 7 days per week and larger populations. Sensitivity analyses revealed that missing ischemic strokes significantly deteriorated economic performance of MSU.

CONCLUSIONS

Major determinants of cost-effectiveness should be addressed when setting up novel MSU programs. Catchment zones of more than 500,000-700,000 inhabitants and operating times of at least 12-16 h per day, 7 days per week could enable the most cost-effective MSU services in the German healthcare system.

Mobile Stroke Unit Management in Patients With Acute Ischemic Stroke Eligible for Intravenous Thrombolysis

Importance

Clinical trials have suggested that prehospital management in a mobile stroke unit (MSU) improves functional outcomes in patients with acute ischemic stroke who are potentially eligible for intravenous thrombolysis, but there is a paucity of real-world evidence from routine clinical practice on this topic.

Objective

To determine the association between prehospital management in an MSU vs standard emergency medical services (EMS) management and the level of global disability at hospital discharge.

Design, Setting, and Participants

This was a retrospective, observational, cohort study that included consecutive patients with a final diagnosis of ischemic stroke who received either prehospital management in an MSU or standard EMS management between August 1, 2018, and January 31, 2023. Follow-up ended at hospital discharge. The primary analytic cohort included those who were potentially eligible for IV thrombolysis. A separate, overlapping cohort including all patients regardless of diagnosis was also analyzed. Patient data were obtained from the American Heart Association's Get With The Guidelines-Stroke (GWTG-Stroke) Program, a nationwide, multicenter quality assurance registry. This analysis was completed in May 2024.

Exposure

Prehospital management in an MSU (vs standard EMS management).

Main Outcomes and Measures

The primary efficacy end point was the utility-weighted modified Rankin Scale (UW-mRS) score. The secondary efficacy end point was independent ambulation status. The coprimary safety end points were symptomatic intracranial hemorrhage (sICH) and in-hospital mortality.

Results

Of 19 433 patients (median [IQR] age, 73 [62-83] years; 9867 female [50.8%]) treated at 106 hospitals, 1237 (6.4%) received prehospital management in an MSU. Prehospital management in an MSU was associated with a better score on the UW-mRS at discharge (adjusted mean difference, 0.03; 95% CI, 0.01-0.05) and a higher likelihood of independent ambulation at discharge (53.3% [468 of 878 patients] vs 48.3% [5868 of 12 148 patients]; adjusted risk ratio [aRR], 1.08; 95% CI, 1.03-1.13). There was no statistically significant difference in sICH (5.2% [57 of 1094] vs 4.2% [545 of 13 014]; aRR, 1.30; 95% CI, 0.94-1.75]) or in-hospital mortality (5.7% [70 of 1237] vs 6.2% [1121 of 18 196]; aRR, 1.03; 95% CI, 0.78-1.27) between the 2 groups.

Conclusions and Relevance

Among patients with acute ischemic stroke potentially eligible for intravenous thrombolysis, prehospital management in an MSU compared with standard EMS management was associated with a significantly lower level of global disability at hospital discharge. These findings support policy efforts to expand access to prehospital MSU management.

Evaluation of a compact cone beam CT concept with high image fidelity for point-of-care brain imaging

Cone beam computed tomography (CBCT) has potential advantages for developing portable, cost-effective point-of-care CT systems for intracranial imaging, such as early stroke diagnosis, hemorrhage detection, and intraoperative navigation. However, large volume imaging with flat panel detector based CBCT significantly increases the scattered radiation fluence which reduces its image quality and utility. To address these issues, a compact CBCT concept with enhanced image quality was investigated for intracranial imaging. The new system features a novel antiscatter collimator and data correction method to address the challenges in imaging large volumes with CBCT. A benchtop CBCT prototype was constructed. Imaging studies with anthropomorphic phantoms showed that soft tissue visualization, Hounsfield Unit (HU) accuracy, contrast, and spatial resolution increased significantly with the proposed CBCT concept, and they were comparable to the values measured in the gold standard multidetector-row CT (MDCT) images. Contrast-to-noise ratio (CNR) in CBCT images was within 12-31% of the CNR in MDCT images. These findings indicate that a compact CBCT system integrated with effective scatter suppression techniques may have increased utility in the context of brain imaging, and the proposed approach may enable the development of point-of-care CT systems for head imaging based on flat panel detector based CBCT technology.

Evaluating the Safety and Efficacy of Telemedicine Physician Assessments on a Mobile Stroke Unit: Protocol for a Prospective Open-Label Blinded End-Point Randomized Controlled Trial

BACKGROUND

Mobile stroke units have been shown to deliver faster patient care and improve clinical outcomes. However, costs associated with staffing limit their use to densely populated cities. Using the Melbourne mobile stroke unit, we aim to evaluate the safety, timeliness, and resource efficiency of a telemedicine model, where the neurologist assesses a patient remotely, via telemedicine, compared with an onboard neurologist model. We hypothesize that, without compromising patient safety, the telemedicine model will provide timely care and superior resource efficiency.

METHODS

Using a prospective, randomized, blinded end-point controlled design, 270 participants consecutively assessed on the Melbourne mobile stroke unit over ≈12 months will be assigned into 2 arms: (1) telemedicine neurologist assessment (intervention) versus (2) onboard assessment (comparator). Enrollment is based on prospectively designated randomized days of neurologist review onboard versus telemedicine. The primary outcome will be the odds that a randomly selected participant in the telemedicine arm will have a better outcome than a randomly selected participant in the onboard arm, measured using a desirability-of-outcome ranking, an outcome measure that includes, in order of importance: (1) safety, (2) scene-to-treatment-decision time metrics, and (3) resource usage. All participants within each arm will be compared with those in the other, resulting in a "win/tie/loss" distribution for telemedicine compared with the onboard model.

CONCLUSIONS

The study will establish whether use of a telemedicine neurologist delivers superior resource efficiency without compromising patient care. This would enable the broader use of mobile stroke units, particularly relevant to regions with limited access to neurologists, thus improving equity in access to time-critical, lifesaving stroke care.

REGISTRATION

URL: clinicaltrials.gov; Unique Identifier: NCT05991310.

Lifetime economic potential of mobile stroke units in acute stroke care: A model-based analysis of the drivers of cost-effectiveness

BACKGROUND AND PURPOSE

To simulate patient-level costs, analyze the economic potential of telemedicine-based mobile stroke units for acute prehospital stroke care, and identify major determinants of cost-effectiveness, based on two recent prospective trials from the United States and Germany.

METHODS

A Markov decision model was developed to simulate lifetime costs and outcomes of mobile stroke unit. The model compares diagnostic and therapeutic pathways of ischemic stroke, hemorrhagic stroke, and stroke mimic patients by conventional care or by mobile stroke units. The treatment outcomes were derived from the B_PROUD and the BEST-mobile stroke unit trials and further input parameters were derived from recent literature. Uncertainty was addressed by deterministic and probabilistic sensitivity analyses. A lifetime horizon based on the US healthcare system was adopted to evaluate different cost thresholds for mobile stroke unit and the resulting cost-effectiveness. Willingness-to-pay thresholds were set at 1x and 3x gross domestic product per capita, as recommended by the World Health Organization.

RESULTS

In the base case scenario, mobile stroke unit care yielded an incremental gain of 0.591 quality-adjusted life years per dispatch. Mobile stroke unit was highly cost-effective up to a maximum average cost of 43,067 US dollars per patient. Sensitivity analyses revealed that MSU cost-effectiveness is mainly affected by reduction of long-term disability costs. Also, among other parameters, the rate of stroke mimics patients diagnosed by MSU plays an important role.

CONCLUSION

This study demonstrated that mobile stroke unit can possibly be operated on an excellent level of cost-effectiveness in urban areas in North America with number of stroke mimic patients and long-term stroke survivor costs as major determinants of lifetime cost-effectiveness.

Mobile stroke units: Beyond thrombolysis

In the last decade, mobile stroke units (MSUs) have shown the potential to transform prehospital stroke care, marking a paradigm shift in delivering ultra-rapid thrombolysis and streamlining triage processes. These units bring acute stroke care directly to patients, significantly shortening treatment times. This review outlines the rationale for MSU care and discusses the potential applications beyond the original purpose of delivering thrombolysis, including large vessel occlusion detection, intracerebral hemorrhage management, and innovative forms of prehospital research.

Establishing an MSU service in a medium-sized German urban area-clinical and economic considerations

Background and purpose

Mobile stroke units (MSU) have been demonstrated to improve prehospital stroke care in metropolitan and rural regions. Due to geographical, social and structural idiosyncrasies of the German city of Mannheim, concepts of established MSU services are not directly applicable to the Mannheim initiative. The aim of the present analysis was to identify major determinants that need to be considered when initially setting up a local MSU service.

Methods

Local stroke statistics from 2015 to 2021 were analyzed and circadian distribution of strokes and local incidence rates were calculated. MSU patient numbers and total program costs were estimated for varying operating modes, daytime coverage models, staffing configurations which included several resource sharing models with the hospital. Additional case-number simulations for expanded catchment areas were performed.

Results

Median time of symptom onset of ischemic stroke patients was 1:00 p.m. 54.3% of all stroke patients were admitted during a 10-h time window on weekdays. Assuming that MSU is able to reach 53% of stroke patients, the average expected number of ischemic stroke patients admitted to MSU would be 0.64 in a 10-h shift each day, which could potentially be increased by expanding the MSU catchment area. Total estimated MSU costs amounted to € 815,087 per annum. Teleneurological assessment reduced overall costs by 11.7%.

Conclusion

This analysis provides a framework of determinants and considerations to be addressed during the design process of a novel MSU program in order to balance stroke care improvements with the sustainable use of scarce resources.

Modern Prehospital Screening Technology for Emergent Neurovascular Disorders

Stroke is a serious neurological disease and a significant contributor to disability worldwide. Traditional in-hospital imaging techniques such as computed tomography (CT) and magnetic resonance imaging (MRI) remain the standard modalities for diagnosing stroke. The development of prehospital stroke detection devices may facilitate earlier diagnosis, initiation of stroke care, and ultimately better patient outcomes. In this review, the authors summarize the features of eight stroke detection devices using noninvasive brain scanning technology. The review summarizes the features of stroke detection devices including portable CT, MRI, transcranial Doppler ultrasound , microwave tomographic imaging, electroencephalography, near-infrared spectroscopy, volumetric impedance phaseshift spectroscopy, and cranial accelerometry. The technologies utilized, the indications for application, the environments indicated for application, the physical features of the eight stroke detection devices, and current commercial products are discussed. As technology advances, multiple portable stroke detection instruments exhibit the promising potential to expedite the diagnosis of stroke and enhance the time taken for treatment, ultimately aiding in prehospital stroke triage.

Modeling the potential efficiency of a blood biomarker-based tool to guide pre-hospital thrombolytic therapy in stroke patients

OBJECTIVES

Stroke treatment with intravenous tissue-type plasminogen activator (tPA) is effective and efficient, but as its benefits are highly time dependent, it is essential to treat the patient promptly after symptom onset. This study evaluates the cost-effectiveness of a blood biomarker test to differentiate ischemic and hemorrhagic stroke to guide pre-hospital treatment with tPA in patients with suspected stroke, compared with standard hospital management. The standard care for patients suffering stroke consists mainly in diagnosis, treatment, hospitalization and monitoring.

METHODS

A Markov model was built with four health states according to the modified Rankin scale, in adult patients with suspected moderate to severe stroke (NIHSS 4-22) within 4.5 hours after symptom onset. A Spanish Health System perspective was used. The time horizon was 15 years. Quality-adjusted life-years (QALYs) and life-years gained (LYGs) were used as a measure of effectiveness. Short- and long-term direct health costs were included. Costs were expressed in Euros (2022). A discount rate of 3% was used. Probabilistic sensitivity analysis and several one-way sensitivity analyses were conducted.

RESULTS

The use of a blood-test biomarker compared with standard care was associated with more QALYs (4.87 vs. 4.77), more LYGs (7.18 vs. 7.07), and greater costs (12,807€ vs. 12,713€). The ICER was 881€/QALY. Probabilistic sensitivity analysis showed that the biomarker test was cost-effective in 82% of iterations using a threshold of 24,000€/QALY.

CONCLUSIONS

The use of a blood biomarker test to guide pre-hospital thrombolysis is cost-effective compared with standard hospital care in patients with ischemic stroke.

Cost-effectiveness of tenecteplase versus alteplase for stroke thrombolysis evaluation trial in the ambulance

BACKGROUND

Tenecteplase administered to patients with ischaemic stroke in a mobile stroke unit (MSU) has been shown to reduce the perfusion lesion volumes and result in ultra-early recovery. We now seek to assess the cost-effectiveness of tenecteplase in the MSU.

METHODS

A within-trial (TASTE-A) economic analysis and a model-based long-term cost-effectiveness analysis were performed. This post hoc within-trial economic analysis utilised the patient-level data (intention to treat, ITT) prospectively collected over the trial to calculate the difference in both healthcare costs and quality-adjusted life years (QALYs, estimated from modified Rankin scale score). A Markov microsimulation model was developed to simulate the long-term costs and benefits.

RESULTS

In total, there were 104 patients with ischaemic stroke randomised to tenecteplase (n = 55) or alteplase (n = 49) treatment groups, respectively in the TASTE-A trial. The ITT-based analysis showed that treatment with tenecteplase was associated with non-signficantly lower costs (A$28,903 vs A$40,150 (p = 0.056)) and greater benefits (0.171 vs 0.158 (p = 0.457)) than that for the alteplase group over the first 90 days post the index stroke. The long-term model showed that tenecteplase led to greater savings in costs (-A$18,610) and more health benefits (0.47 QALY or 0.31 LY gains). Tenecteplase-treated patients had reduced costs for rehospitalisation (-A$1464), nursing home care (-A$16,767) and nonmedical care (-A$620) per patient.

CONCLUSIONS

Treatment of ischaemic stroke patients with tenecteplase appeared to be cost-effective and improve QALYs in the MSU setting based on Phase II data. The reduced total cost from tenecteplase was driven by savings from acute hospitalisation and reduce need for nursing home care.

Prehospital Stroke Care Part 2: On-Scene Evaluation and Management by Emergency Medical Services Practitioners

The prehospital phase is a critical component of delivering high-quality acute stroke care. This topical review discusses the current state of prehospital acute stroke screening and transport, as well as new and emerging advances in prehospital diagnosis and treatment of acute stroke. Topics include prehospital stroke screening, stroke severity screening, emerging technologies to aid in the identification and diagnosis of acute stroke in the prehospital setting, prenotification of receiving emergency departments, decision support for destination determination, and the capabilities and opportunities for prehospital stroke treatment in mobile stroke units. Further evidence-based guideline development and implementation of new technologies are critical for ongoing improvements in prehospital stroke care.

Sustaining a New Model of Acute Stroke Care: A Mixed-Method Process Evaluation of the Melbourne Mobile Stroke Unit

BACKGROUND

Internationally, Mobile Stroke Unit (MSU) ambulances have changed pre-hospital acute stroke care delivery. MSU clinical and cost-effectiveness studies are emerging, but little is known about important factors for achieving sustainability of this innovative model of care.

METHODS

Mixed-methods study from the Melbourne MSU (operational since November 2017) process evaluation. Participant purposive sampling included clinical, operational and executive/management representatives from Ambulance Victoria (AV) (emergency medical service provider), the MSU clinical team, and receiving hospitals. Sustainability was defined as ongoing MSU operations, including MSU workforce and future model considerations. Theoretically-based on-line survey with Unified Theory of Acceptance and Use of Technology (UTAUT), Self Determination Theory (SDT, Intrinsic Motivation), and open-text questions targeting barriers and benefits was administered (June-September 2019). Individual/group interviews were conducted, eliciting improvement suggestions and requirements for ongoing use. Descriptive and regression analyses (quantitative data) and directed content and thematic analysis (open text and interview data) were conducted.

RESULTS

There were 135 surveys completed. Identifying that the MSU was beneficial to daily work (β=0.61), not experiencing pressure/tension about working on the MSU (β=0.17) and thinking they did well working within the team model (β=0.17) were significantly associated with wanting to continue working within the MSU model [R2=0.76; F(15, 60)=12.76, P<.001]. Experiences varied between those on the MSU team and those working with the MSU. Advantages were identified for patients (better, faster care) and clinicians (interdisciplinary learning). Disadvantages included challenges integrating into established systems, and establishing working relationships. Themes identified from 35 interviews were MSU team composition, MSU vehicle design and layout, personnel recruitment and rostering, communication improvements between organisations, telemedicine options, MSU operations and dispatch specificity.

CONCLUSION

Important factors affecting the sustainability of the MSU model of stroke care emerged. A cohesive team approach, with identifiable benefits and good communication between participating organisations is important for clinical and operational sustainability.

Cost-effectiveness of improvement strategies for reperfusion treatments in acute ischemic stroke: a systematic review

BACKGROUND

Reducing delays along the acute stroke pathway significantly improves clinical outcomes for acute ischemic stroke patients eligible for reperfusion treatments. The economic impact of different strategies reducing onset to treatment (OTT) is crucial information for stakeholders in acute stroke management. This systematic review aimed to provide an overview on the cost-effectiveness of several strategies to reduce OTT.

METHODS

A comprehensive literature search was conducted in EMBASE, PubMed, and Web of Science until January 2022. Studies were included if they reported 1/ stroke patients treated with intravenous thrombolysis and/or endovascular thrombectomy, 2/ full economic evaluation, and 3/ strategies to reduce OTT. The Consolidated Health Economic Evaluation Reporting Standards statement was applied to assess the reporting quality.

RESULTS

Twenty studies met the inclusion criteria, of which thirteen were based on cost-utility analysis with the incremental cost-effectiveness ratio per quality-adjusted life year gained as the primary outcome. Studies were performed in twelve countries focusing on four main strategies: educational interventions, organizational models, healthcare delivery infrastructure, and workflow improvements. Sixteen studies showed that the strategies concerning educational interventions, telemedicine between hospitals, mobile stroke units, and workflow improvements, were cost-effective in different settings. The healthcare perspective was predominantly used, and the most common types of models were decision trees, Markov models and simulation models. Overall, fourteen studies were rated as having high reporting quality (79%-94%).

CONCLUSIONS

A wide range of strategies aimed at reducing OTT is cost-effective in acute stroke care treatment. Existing pathways and local characteristics need to be taken along in assessing proposed improvements.

Prehospital technologies for early stroke detection - A review

The rate of neural circuitry loss in a typical large vessel occlusion well emphasizes that 'Time is Brain'. Every untreated minute in a large vessel ischaemic stroke results in loss of 1.9 million neurons and 13.8 billion synapses. As such, it is essential to optimize the flow-limiting steps in delivering the current standard of care. The current diagnostic model involves recognition of symptoms by patients, followed by access to Emergency Medical Services and subsequent physical examination and neuroimaging in the Emergency Department. With more than 50% of stroke patients using Emergency Medical Services as the first point of care contact, it can be deduced that the outcome of the 'stroke chain of survival' can be improved by addressing the bottleneck of prehospital stroke diagnosis. Here we present a review of the existing technologies.

Comparison of image quality between a novel mobile CT scanner and current generation stationary CT scanners

PURPOSE

Point-of-care imaging with mobile CT scanners offers several advantages, provided that the image quality is satisfactory. Our aim was to compare image quality of a novel mobile CT to stationary scanners for patients in a neurosurgical intensive care unit (ICU).

METHODS

From November 2020 to April 2021, all patients above 18 years of age examined by a mobile CT scanner at a neurosurgical ICU were included if they also had a stationary head CT examination during the same hospitalization. Quantitative image quality parameters included attenuation and noise in six predefined regions of interest, as well as contrast-to-noise ratio between gray and white matter. Subjective image quality was rated on a 4-garde scale, by four radiologists blinded to scanner parameters.

RESULTS

Fifty patients were included in the final study population. Radiation dose and image attenuation values were similar for mobCT and stationary CTs. There was a small statistically significant difference in subjective quality rating between mobCT and stationary CT images. Two radiologists favored the stationary CT images, one was neutral, and one favored mobCT images. For overall image quality, 14% of mobCT images were rated grade 1 (poor image quality) compared to 8% for stationary CT images.

CONCLUSION

Point-of-care brain CT imaging was successfully performed on clinical neurosurgical ICU patients with small reduction in image quality, predominantly affecting the posterior fossa, compared to high-end stationary CT scanners.

Cost-Effectiveness of Mobile Stroke Unit Care in Norway

BACKGROUND:

Acute ischemic stroke treatment in mobile stroke units (MSUs) reduces time-to-treatment and increases thrombolytic rates, but implementation requires substantial investments. We wanted to explore the cost-effectiveness of MSU care incorporating novel efficacy data from the Norwegian MSU study, Treat-NASPP (the Norwegian Acute Stroke Prehospital Project).

METHODS:

We developed a Markov model linking improvements in time-to-treatment and thrombolytic rates delivered by treatment in an MSU to functional outcomes for the patients in a lifetime perspective. We estimated incremental costs, health benefits, and cost-effectiveness of MSU care as compared with conventional care. In addition, we estimated a minimal MSU utilization level for the intervention to be cost-effective in the publicly funded health care system in Norway.

RESULTS:

MSU care was associated with an expected quality-adjusted life-year-gain of 0.065 per patient, compared with standard care. Our analysis suggests that about 260 patients with ischemic stroke need to be treated with MSU annually to result in an incremental cost-effectiveness ratio of about NOK385 000 (US$43 780) per quality-adjusted life-year for MSU compared with standard care. The incremental cost-effectiveness ratio varies between some NOK1 000 000 (US$113 700) per quality-adjusted life-year if an MSU treats 100 patients per year and to about NOK340 000 (US$38 660) per quality-adjusted life-year if 300 patients with acute ischemic stroke are treated.

CONCLUSIONS:

MSU care in Norwegian settings is potentially cost-effective compared with conventional care, but this depends on a relatively high annual number of treated patients with acute ischemic stroke per vehicle. These results provide important information for MSU implementation in government-funded health care systems.

The Mobile Stroke Unit Nurse: An International Exploration of Their Scope of Practice, Education, and Training

ABSTRACT

BACKGROUND: Mobile stroke units (MSUs) are ambulance-based prehospital stroke care services. Through immediate roadside assessment and onboard brain imaging, MSUs provide faster stroke management with improved patient outcomes. Mobile stroke units have enabled the development of expanded scope of practice for stroke nurses; however, there is limited published evidence about these evolving prehospital acute nursing roles. AIMS: The aim of this study was to explore the expanded scope of practice of nurses working on MSUs by identifying MSUs with onboard nurses; describing the roles and responsibilities, training, and experience of MSU nurses, through a search of the literature; and describing 2 international MSU services incorporating nurses from Memphis, Tennessee, and Melbourne, Australia. METHODS: We searched PubMed, CINAHL, and the Joanna Briggs Institute Evidence-Based Practice database using the terms "mobile stroke unit" and "nurse." Existing MSUs were identified through the PRE-hospital Stroke Treatment Organization to determine models that involved nurses. We describe 2 MSUs involving nurses: one in Memphis and one in Melbourne, led by 2 of our authors. RESULTS: Ninety articles were found describing 15 MSUs; however, staffing details were lacking, and it is unknown how many employ nurses. Nine articles described the role of the nurse, but role specifics, training, and expertise were largely undocumented. The MSU in Memphis, the only unit to be staffed exclusively by onboard nurse practitioners, is supported by a neurologist who consults via telephone. The Melbourne MSU plans to trial a nurse-led telemedicine model in the near future. CONCLUSION: We lack information on how many MSUs employ nurses, and the nurses' scope of practice, training, and expertise. Expert stroke nurse practitioners can safely perform many of the tasks undertaken by the onboard neurologist, making a nurse-led telemedicine model an effective and potentially cost-effective model that should be considered for all MSUs.

Mobile Stroke Units: Evidence, Gaps, and Next Steps

Mobile stroke units (MSUs) are specialized ambulances equipped with the personnel, equipment, and imaging capability to diagnose and treat acute stroke in the prehospital setting. Over the past decade, MSUs have proliferated throughout the world, particularly in European and US cities, culminating in the formation of an international consortium. Randomized trials have demonstrated that MSUs increase stroke thrombolysis rates and reduce onset-to-treatment times but until recently it was uncertain if these advantages would translate into better patient outcomes. In 2021, 2 pivotal, large, controlled clinical trials, B_PROUD and BEST-MSU, demonstrated that as compared with conventional emergency care, treatment aboard MSUs was safe and led to improved functional outcomes in patients with stroke. Further, the observed benefit of MSUs appeared to be primarily driven by the higher frequency of ultra-early thrombolysis within the golden hour. Nevertheless, questions remain regarding the cost-effectiveness of MSUs, their utility in nonurban settings, and optimal infrastructure. In addition, in much of the world, MSUs are currently not reimbursed by insurers nor accepted as standard care by regulatory bodies. As MSUs are now established as one of the few proven acute stroke interventions with an effect size that is comparable to that of intravenous thrombolysis and stroke units, stroke leaders and organizations should work with emergency medical services, governments, and community stakeholders to determine how MSUs might benefit individual communities, and their optimal organization and financing. Future research to explore the effect of MSUs on intracranial hemorrhage and thrombectomy outcomes, cost-effectiveness, and novel models including the use of rendezvous transports, helicopters, and advanced neuroimaging is ongoing. Recommended next steps for MSUs include reimbursement by insurers, integration with ambulance networks, recognition by program accreditors, and inclusion in registries that monitor care quality.

A Systematic Review of Mobile Stroke Unit Among Acute Stroke Patients: Time Metrics, Adverse Events, Functional Result and Cost-Effectiveness

Background

Mobile stroke unit (MSU) is deployed to shorten the duration of ischemic stroke recognition to thrombolysis treatment, thus reducing disability, mortality after an acute stroke attack, and related economic burden. Therefore, we conducted a comprehensive systematic review of the clinical trial and economic literature focusing on various outcomes of MSU compared with conventional emergency medical services (EMS).

Methods

An electronic search was conducted in four databases (PubMed, OVID Medline, Embase, and the Cochrane Controlled Register of Trials) from 1990 to 2021. In these trials, patients with acute stroke were assigned to receive either MSU or EMS, with clinical and economic outcomes. First, we extracted interested data in the pooled population and conducted a subgroup analysis to examine related heterogeneity. We then implemented a descriptive analysis of economic outcomes. All analyses were performed with R 4.0.1 software.

Results

A total of 22,766 patients from 16 publications were included. In total 7,682 (n = 33.8%) were treated in the MSU and 15,084 (n = 66.2%) in the conventional EMS. Economic analysis were available in four studies, of which two were based on trial data and the others on model simulations. The pooled analysis of time metrics indicated a mean reduction of 32.64 min (95% confidence interval: 23.38–41.89, p &lt; 0.01) and 28.26 minutes (95% CI: 16.11–40.41, p &lt; 0.01) in the time-to-therapy and time-to-CT completion, respectively in the MSU. However, there was no significant difference on stroke-related neurological events (OR = 0.94, 95% CI: 0.70–1.27, p = 0.69) and in-hospital mortality (OR = 1.11, 95% CI: 0.83–1.50, p = 0.48) between the MSU and EMS. The proportion of patients with modified Ranking scale (mRS) of 0–2 at 90 days from onset was higher in the MSU than EMS (p &lt; 0.05). MSU displayed favorable benefit-cost ratios (2.16–6.85) and incremental cost-effectiveness ratio ($31,911 /QALY and $38,731 per DALY) comparing to EMS in multiple economic publications. Total cost data based on 2014 USD showed that the MSU has the highest cost in Australia ($1,410,708) and the lowest cost in the USA ($783,463).

Conclusion

A comprehensive analysis of current research suggests that MUS, compared with conventional EMS, has a better performance in terms of time metrics, safety, long-term medical benefits, and cost-effectiveness.

Comparison of Mobile Stroke Unit With Usual Care for Acute Ischemic Stroke Management: A Systematic Review and Meta-analysis

IMPORTANCE

So far, uncertainty remains as to whether there is sufficient cumulative evidence that mobile stroke unit (MSU; specialized ambulance equipped with computed tomography scanner, point-of-care laboratory, and neurological expertise) use leads to better functional outcomes compared with usual care.

OBJECTIVE

To determine with a systematic review and meta-analysis of the literature whether MSU use is associated with better functional outcomes in patients with acute ischemic stroke (AIS).

DATA SOURCES

MEDLINE, Cochrane Library, and Embase from 1960 to 2021.

STUDY SELECTION

Studies comparing MSU deployment and usual care for patients with suspected stroke were eligible for analysis, excluding case series and case-control studies.

DATA EXTRACTION AND SYNTHESIS

Independent data extraction by 2 observers, following the PRISMA and MOOSE reporting guidelines. The risk of bias in each study was determined using the ROBINS-I and RoB2 tools. In the case of articles with partially overlapping study populations, unpublished disentangled results were obtained. Data were pooled in random-effects meta-analyses.

MAIN OUTCOMES AND MEASURES

The primary outcome was excellent outcome as measured with the modified Rankin Scale (mRS; score of 0 to 1 at 90 days).

RESULTS

Compared with usual care, MSU use was associated with excellent outcome (adjusted odds ratio [OR], 1.64; 95% CI, 1.27-2.13; P < .001; 5 studies; n = 3228), reduced disability over the full range of the mRS (adjusted common OR, 1.39; 95% CI, 1.14-1.70; P = .001; 3 studies; n = 1563), good outcome (mRS score of 0 to 2: crude OR, 1.25; 95% CI, 1.09-1.44; P = .001; 6 studies; n = 3266), shorter onset-to-intravenous thrombolysis (IVT) times (median reduction, 31 minutes [95% CI, 23-39]; P < .001; 13 studies; n = 3322), delivery of IVT (crude OR, 1.83; 95% CI, 1.58-2.12; P < .001; 7 studies; n = 4790), and IVT within 60 minutes of symptom onset (crude OR, 7.71; 95% CI, 4.17-14.25; P < .001; 8 studies; n = 3351). MSU use was not associated with an increased risk of all-cause mortality at 7 days or at 90 days or with higher proportions of symptomatic intracranial hemorrhage after IVT.

CONCLUSIONS AND RELEVANCE

Compared with usual care, MSU use was associated with an approximately 65% increase in the odds of excellent outcome and a 30-minute reduction in onset-to-IVT times, without safety concerns. These results should help guideline writing committees and policy makers.

European Stroke Organisation (ESO) guidelines on mobile stroke units for prehospital stroke management

The safety and efficacy of mobile stroke units (MSUs) in prehospital stroke management has recently been investigated in different clinical studies. MSUs are ambulances equipped with a CT scanner, point-of-care lab, telemedicine and are staffed with a stroke specialised medical team. This European Stroke Organisation (ESO) guideline provides an up-to-date evidence-based recommendation to assist decision-makers in their choice on using MSUs for prehospital management of suspected stroke, which includes patients with acute ischaemic stroke (AIS), intracranial haemorrhage (ICH) and stroke mimics. The guidelines were developed according to the ESO standard operating procedure and Grading of Recommendations, Assessment, Development and Evaluation (GRADE) methodology. The working group identified relevant clinical questions, performed systematic reviews and aggregated data meta-analyses of the literature, assessed the quality of the available evidence and made specific recommendations. Expert consensus statements are provided where sufficient evidence was not available to provide recommendations based on the GRADE approach. We found moderate evidence for suggesting MSU management for patients with suspected stroke. The patient group diagnosed with AIS shows an improvement of functional outcomes at 90 days, reduced onset to treatment times and increased proportion receiving IVT within 60 min from onset. MSU management might be beneficial for patients with ICH as MSU management was associated with a higher proportion of ICH patients being primarily transported to tertiary care stroke centres. No safety concerns (all-cause mortality, proportion of stroke mimics treated with IVT, symptomatic intracranial bleeding and major extracranial bleeding) could be identified for all patients managed with a MSU compared to conventional care. We suggest MSU management to improve prehospital management of suspected stroke patients.

Mobile Stroke Units: Current Evidence and Impact

PURPOSE OF REVIEW

Several approaches have been developed to optimize prehospital systems for acute stroke given poor access and significant delays to timely treatment. Specially equipped ambulances that directly initiate treatment, known as Mobile Stroke Units (MSUs), have rapidly proliferated across the world. This review provides a comprehensive summary on the efficacy of MSUs in acute stroke, its various applications beyond thrombolysis, as well as the establishment, optimal setting and cost-effectiveness of incorporating an MSU into healthcare systems.

RECENT FINDINGS

MSUs speed stroke treatment into the first "golden hour" when better outcomes from thrombolysis are achieved. While evidence for the positive impact of MSUs on outcomes was previously unavailable, two recent landmark controlled trials, B_PROUD and BEST-MSU, show that MSUs result in significantly lesser disability compared to conventional ambulance care. Emerging literature prove the significant impact of MSUs. Adaptability however remains limited by significant upfront financial investment, challenges with reimbursements and pending evidence on their cost-effectiveness.

Shifting acute stroke management to the prehospital setting

PURPOSE OF REVIEW

The earlier the treatment, the better the outcomes after acute ischemic stroke. Optimizing prehospital care bears potential to shorten treatment times. We here review the recent literature on mothership vs. drip-and-ship as well as mobile stroke unit concepts.

RECENT FINDINGS

Mobile stroke units result in the shortest onset-to-treatment times in mostly urban settings.

SUMMARY

Future research should focus on further streamlining processes around mobile stroke units, especially improving dispatch algorithms and improve referral for endovascular therapy.

A Case for the Non-Neurologist Telestroke Provider

Introduction: Telestroke networks have effectively increased the number of ischemic stroke patients who have access to acute stroke therapy. However, the availability of a dedicated group of stroke subspecialists is not always feasible. We hypothesize that rates of tPA recommendation, sensitivity of final diagnosis, and post-tPA hemorrhagic complications do not differ significantly between neurologists and an emergency-medicine physician during telestroke consultations.

Methods: Retrospective review of all telestroke consults performed at a comprehensive stroke center over 1 year. Statistical analysis: Chi squared test.

Results: Three hundred and three consults were performed among 6 spoke sites. 16% (48/303) were completed by the emergency medicine physician; 25% (76/303) were performed by non-stroke-trained neurologists, and 59% (179/303) were completed by a board-certified Vascular Neurologist. Overall rate of tPA recommendation was 40% (104/255), 38% (18/48), 41% (73/179), and 41% (31/76) among the all neurology-trained, emergency medicine-trained, stroke neurology-trained and other neurology- trained provider groups, respectively (p = 0.427). Sensitivity of final stroke diagnosis was 77% (14/18) and 72% (75/104) in the emergency-medicine trained and neurology-trained provider groups (p = 0.777) No symptomatic hemorrhagic complications following the administration of tPA via telestroke consultation occurred in any group over this time period. One asymptomatic intracerebral hemorrhage was observed (0.96% or 1/104) in the neurology-trained provider group.

Discussion/Conclusion: Our results did not illustrate any statistically significant difference between care provided by an emergency medicine-trained physician and neurologists during telestroke consultation. While our study is limited by its relatively low numbers, it suggests that identifying a non-neurologist provider who has requisite clinical experience with acute stroke patients can safely and appropriately provide telestroke consultation. The lack of formerly trained neurologists, therefore, may not need to serve as an impediment to building an effective telestroke network. Future efforts should be focused on illuminating all strategies that facilitate sustainable telestroke implementation.

Impact of mobile stroke units

Since its first introduction in clinical practice in 2008, the concept of mobile stroke unit enabling prehospital stroke treatment has rapidly expanded worldwide. This review summarises current knowledge in this young field of stroke research, discussing topics such as benefits in reduction of delay before treatment, vascular imaging-based triage of patients with large-vessel occlusion in the field, differential blood pressure management or prehospital antagonisation of anticoagulants. However, before mobile stroke units can become routine, several questions remain to be answered. Current research, therefore, focuses on safety, long-term medical benefit, best setting and cost-efficiency as crucial determinants for the sustainability of this novel strategy of acute stroke management.

Association Between Dispatch of Mobile Stroke Units and Functional Outcomes Among Patients With Acute Ischemic Stroke in Berlin

IMPORTANCE

Effects of thrombolysis in acute ischemic stroke are time-dependent. Ambulances that can administer thrombolysis (mobile stroke units [MSUs]) before arriving at the hospital have been shown to reduce time to treatment.

OBJECTIVE

To determine whether dispatch of MSUs is associated with better clinical outcomes for patients with acute ischemic stroke.

DESIGN, SETTING, AND PARTICIPANTS

This prospective, nonrandomized, controlled intervention study was conducted in Berlin, Germany, from February 1, 2017, to October 30, 2019. If an emergency call prompted suspicion of stroke, both a conventional ambulance and an MSU, when available, were dispatched. Functional outcomes of patients with final diagnosis of acute cerebral ischemia who were eligible for thrombolysis or thrombectomy were compared based on the initial dispatch (both MSU and conventional ambulance or conventional ambulance only).

EXPOSURE

Simultaneous dispatch of an MSU (computed tomographic scanning with or without angiography, point-of-care laboratory testing, and thrombolysis capabilities on board) and a conventional ambulance (n = 749) vs conventional ambulance alone (n = 794).

MAIN OUTCOMES AND MEASURES

The primary outcome was the distribution of modified Rankin Scale (mRS) scores (a disability score ranging from 0, no neurological deficits, to 6, death) at 3 months. The coprimary outcome was a 3-tier disability scale at 3 months (none to moderate disability; severe disability; death) with tier assignment based on mRS scores if available or place of residence if mRS scores were not available. Common odds ratios (ORs) were used to quantify the association between exposure and outcome; values less than 1.00 indicated a favorable shift in the mRS distribution and lower odds of higher levels of disability.

RESULTS

Of the 1543 patients (mean age, 74 years; 723 women [47%]) included in the adjusted primary analysis, 1337 (87%) had available mRS scores (primary outcome) and 1506 patients (98%) had available the 3-tier disability scale assessment (coprimary outcome). Patients with an MSU dispatched had lower median mRS scores at month 3 (1; interquartile range [IQR], 0-3) than did patients without an MSU dispatched (2; IQR, 0-3; common OR for worse mRS, 0.71; 95% CI, 0.58-0.86; P < .001). Similarly, patients with an MSU dispatched had lower 3-month coprimary disability scores: 586 patients (80.3%) had none to moderate disability; 92 (12.6%) had severe disability; and 52 (7.1%) had died vs patients without an MSU dispatched: 605 (78.0%) had none to moderate disability; 103 (13.3%) had severe disability; and 68 (8.8%) had died (common OR for worse functional outcome, 0.73, 95% CI, 0.54-0.99; P = .04).

CONCLUSIONS AND RELEVANCE

In this prospective, nonrandomized, controlled intervention study of patients with acute ischemic stroke in Berlin, Germany, the dispatch of mobile stroke units, compared with conventional ambulances alone, was significantly associated with lower global disability at 3 months. Clinical trials in other regions are warranted.

Mobile Stroke Units: Current and Future Impact on Stroke Care

Ischemic stroke is a leading cause of death and major disability that impacts societies across the world. Earlier thrombolysis of blocked arteries with intravenous tissue plasminogen activator (tPA) and/or endovascular clot extraction is associated with better clinical outcomes. Mobile stroke units (MSU) can deliver faster tPA treatment and rapidly transport stroke patients to centers with endovascular capabilities. Initial MSU trials in Germany indicated more rapid tPA treatment times using MSUs compared with standard emergency room treatment, a higher proportion of patients treated within 60 minutes of stroke onset, and a trend toward better 3-month clinical outcomes with MSU care. In the United States, the first multicenter, randomized clinical trial comparing standard versus MSU treatment began in 2014 in Houston, TX, and has demonstrated feasibility and safety of MSU operations, reliability of telemedicine technology to assess patients for tPA eligibility without additional time delays, and faster door-to-groin puncture times of MSU patients needing endovascular thrombectomy in interim analysis. Scheduled for completion in 2021, this trial will determine the cost-effectiveness and benefit of MSU treatment on clinical outcomes compared with standard ambulance and hospital treatment. Beyond ischemic stroke, MSUs have additional clinical and research applications that can profoundly impact other cohorts of patients who require time-sensitive neurological care.

Comparative Study on the Outcome of Stroke Patients Transferred by Doctor Helicopters and Ground Ambulances in South Korea: A Retrospective Controlled Study

The purpose of this study was to analyze the effectiveness of helicopter emergency medical services (HEMS) for its economic operations in South Korea. This study targeted stroke patients who were transported via HEMS or ground emergency medical services (GEMS) from the scene of an accident to a regional emergency medical center. From this patient population, stroke patients who traveled at least 50 km from the scene of the cerebral infarction to the hospital with analyzable outcome data were extracted and included in this study. This study included 26 HEMS and 102 GEMS stroke patients from a pool of 183 potential patients. The survival-to-discharge rate of patients transported via HEMS (96.2%; 25/26) was significantly higher than that of patients transported via GEMS (83.2%; 104/128) (P=0.001). The HEMS transfer was quicker with respect to the decision-making process because the emergency physician actively evaluates and communicates on-site and during in-transit travel to request an appointment immediately upon arrival at the emergency room. These results indicate that using HEMS increased discharge and survival rates and reduced in-hospital mortality of HEMS of stroke patients with a reduced admission time. This result association leads to reasonable cost-effectiveness and efficient estimates overall. In conclusion, HEMS indicate reduced time taken for stroke patients to be hospitalized and treated and decreased mortality after 24 hours. According to this result, HEMS transport can be more effective than GEMS in long-distance delivery of stroke patients.

Stroke systems of care in high-income countries: what is optimal?

Stroke is a complex, time-sensitive, medical emergency that requires well functioning systems of care to optimise treatment and improve patient outcomes. Education and training campaigns are needed to improve both the recognition of stroke among the general public and the response of emergency medical services. Specialised stroke ambulances (mobile stroke units) have been piloted in many cities to speed up the diagnosis, triage, and emergency treatment of people with acute stroke symptoms. Hospital-based interdisciplinary stroke units remain the central feature of a modern stroke service. Many have now developed a role in the very early phase (hyperacute units) plus outreach for patients who return home (early supported discharge services). Different levels (comprehensive and primary) of stroke centre and telemedicine networks have been developed to coordinate the various service components with specialist investigations and interventions including rehabilitation. Major challenges include the harmonisation of resources for stroke across the whole patient journey (including the rapid, accurate triage of patients who require highly specialised treatment in comprehensive stroke centres) and the development of technology to improve communication across different parts of a service.

Telestroke strategies to enhance acute stroke management in rural settings: A systematic review and meta-analysis

BACKGROUND

The potential of telestroke implementation in resource-limited areas has yet to be systematically evaluated. This study aims to investigate the implementation of telestroke on acute stroke care in rural areas.

METHODS

Eligible studies published up to November 2019 were included in this study. Randomized trials were further evaluated for risk of bias with Cochrane RoB 2, while nonrandomized studies with ROBINS-I tool. Random effects model was utilized to estimate effect sizes, and the certainty of evidence was assessed using the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) tool.

RESULTS

The search yielded 19 studies involving a total of 28,496 subjects, comprising of prehospital and in-hospital telestroke interventions in the form of mobile stroke units and hub-and-spoke hospitals network, respectively. Telestroke successfully increased the proportion of patients treated ≤3 hr (OR 2.15; 95% CI 1.37-3.40; I²  = 0%) and better three-month functional outcome (OR 1.29; 95% CI 1.01-1.63; I²  = 44%) without increasing symptomatic intracranial hemorrhage rate (OR 1.27; 0.65-2.49; I²  = 0%). Furthermore, telestroke was also associated with shorter onset-to-treatment time (mean difference -27.97 min; 95% CI -35.51, -20.42; I²  = 63%) and lower in-hospital mortality rate (OR 0.67; 95% CI 0.52-0.87; I²  = 0%). GRADE assessments yielded low-to-moderate certainty of body evidences.

CONCLUSION

Telestroke implementation in rural areas was associated with better clinical outcomes as compared to usual care. Its integration in both prehospital and in-hospital settings could help optimize emergency stroke approach. Further studies with higher-level evidence are needed to confirm these findings.

Early administration of steroids in the ambulance setting: Protocol for a type I hybrid effectiveness-implementation trial with a stepped wedge design

BACKGROUND

Pediatric asthma exacerbations are a frequent reason for emergency care. Early administration of oral systemic corticosteroids (OCS) in the emergency department (ED) decreases hospitalization rates and ED length-of-stay (LOS). However, it is unknown whether even earlier OCS administration by emergency medical services (EMS) in the prehospital setting further improves outcomes.

PURPOSE

To describe the background and methods of a type 1 hybrid effectiveness-implementation trial of EMS-administered OCS for pediatric asthma patients incorporating a stepped wedge design and the RE-AIM framework.

METHODS

The study employs a non-randomized stepped wedge design where multiple EMS agencies adopt OCS as a treatment for pediatric asthma exacerbations at varying times. This design accommodates ethical considerations of studying pediatric subjects in the prehospital setting where informed consent is not feasible. We will compare hospitalization rates, ED LOS, and short-term healthcare costs between pediatric asthma patients who do and do not receive OCS from EMS. Using geographic information systems (GIS), we will measure how differences in outcomes scale with increasing EMS transport time. We will use the RE-AIM framework to guide a mixed methods analysis of barriers and enablers to EMS administration of OCS for pediatric asthma patients, including quantitative measures of adoption and uptake and qualitative EMS provider focus group data.

CONCLUSION

This trial will determine if earlier EMS administration of OCS to pediatric asthma patients decreases hospitalizations, ED LOS, and short-term healthcare costs, and if those outcomes scale with longer EMS transport times. We will identify barriers and enablers to implementing EMS-administered OCS for pediatric asthma patients.

Economic evaluation of the Melbourne Mobile Stroke Unit

BACKGROUND

The Melbourne Mobile Stroke Unit (MSU) is the first Australian service to provide prehospital acute stroke treatment, including thrombolysis and facilitated triage for endovascular thrombectomy.

AIMS

To estimate the cost-effectiveness of the MSU during the first full year of operation compared with standard ambulance and hospital stroke care pathways (standard care).

METHODS

The costs and benefits of the Melbourne MSU were estimated using an economic simulation model. Operational costs and service utilization data were obtained from the MSU financial and patient tracking reports. The health benefits were estimated as disability-adjusted life years (DALYs) avoided using local data on reperfusion therapy and estimates from the published literature on their effectiveness. Costs were presented in Australian dollars. The robustness of results was assessed using multivariable (model inputs varied simultaneously: 10,000 Monte Carlo iterations) and various one-way sensitivity analyses.

RESULTS

In 2018, the MSU was dispatched to 1244 patients during 200 days of operation. Overall, 167 patients were diagnosed with acute ischemic stroke, and 58 received thrombolysis, endovascular thrombectomy, or both. We estimated 27.94 DALYs avoided with earlier access to endovascular thrombectomy (95% confidence interval (CI) 15.30 to 35.93) and 16.90 DALYs avoided with improvements in access to thrombolysis (95% CI 9.05 to 24.68). The MSU was estimated to cost an additional $30,982 per DALY avoided (95% CI $21,142 to $47,517) compared to standard care.

CONCLUSIONS

There is evidence that the introduction of MSU is cost-effective when compared with standard care due to earlier provision of reperfusion therapies.

Emerging therapies in acute ischemic stroke

Thrombolysis and mechanical thrombectomy have revolutionized the care of patients with acute ischemic stroke. The number of patients who can benefit from these treatments continues to increase as new studies demonstrate that not just time since stroke onset but also collateral circulation influences outcome. Technologies such as telestroke, mobile stroke units, and artificial intelligence are playing an increasing role in identifying and treating stroke. Stroke-systems-of-care models continue to streamline the delivery of definitive revascularization in the age of mechanical thrombectomy.

A review of mobile stroke units

PURPOSE OF REVIEW

Mobile stroke units (MSUs) for prehospital treatment and management of patients with acute stroke have been developed more than a decade ago and is currently spreading worldwide. This review discusses the history of MSU and current operations and research.

RECENT FINDINGS

Multiple studies have shown that MSU can significantly reduce treatment time with a tenfold increase of patients treated within the first 60 min of symptom onset. Recent preliminary results from the Berlin Prehospital or Usual Delivery of Acute Stroke Care trial (B-PROUD) showed a positive shift in modified Rankin Scale (mRS) scores at 3 months for patients treated in MSUs. Two German studies indicate that the MSU model is cost effective by reducing disability and improving adjusted quality-life years after stroke. The MSU model for prehospital management of acute stroke is spreading worldwide. More research is needed, however, to establish cost-effectiveness, efficacy and best setting for prehospital stroke management.

Acute ischemic stroke: improving access to intravenous tissue plasminogen activator

INTRODUCTION

Since approval by the United States Food and Drug Administration in 1996, alteplase utilization rates for acute ischemic stroke have increased. Despite its efficacy for improving stroke outcomes, however, the majority of ischemic stroke patients still do not receive alteplase. To address this issue, different methods for improving access to alteplase have been tested with varying degrees of success.

AREAS COVERED

This article gives an overview of the recent approaches pursued to improve access to alteplase for acute ischemic stroke patients. Utilization of stroke systems of care, quality metrics, and quality-improvement initiatives to improve alteplase treatment rates are discussed. The implementation of Telestroke networks to improve access and timely evaluation by a stroke specialist are also reviewed. Lastly, this review discusses the use of neuroimaging techniques to identify alteplase candidates in stroke of unknown symptom onset or beyond the 4.5-h treatment window.

EXPERT COMMENTARY

Expanding access to alteplase therapy for acute ischemic stroke is a multi-faceted approach. Specific considerations based on region, population, and health-care resources should be considered for each strategy. Neuroimaging approaches to identify alteplase-eligible patients beyond the 4.5-h treatment window are a recent development in acute stroke care that holds promise for increasing alteplase treatment rates.

Melbourne Mobile Stroke Unit and Reperfusion Therapy

Background and Purpose—

Mobile stroke units (MSUs) are increasingly used worldwide to provide prehospital triage and treatment. The benefits of MSUs in giving earlier thrombolysis have been well established, but the impacts of MSUs on endovascular thrombectomy (EVT) and effect on disability avoidance are largely unknown. We aimed to determine the clinical impact and disability reduction for reperfusion therapies in the first operational year of the Melbourne MSU.

Methods—

Treatment time metrics for MSU patients receiving reperfusion therapy were compared with control patients presenting to metropolitan Melbourne stroke units via standard ambulance within MSU operating hours. The primary outcome was median time difference in first ambulance dispatch to treatment modeled using quantile regression analysis. Time savings were subsequently converted to disability-adjusted life years avoided using published estimates.

Results—

In the first 365-day operation of the Melbourne MSU, prehospital thrombolysis was administered to 100 patients (mean age, 73.8 years; 62% men). The median time savings per MSU patient, compared with the control cohort, was 26 minutes ( P <0.001) for dispatch to hospital arrival and 15 minutes ( P <0.001) for hospital arrival to thrombolysis. The calculated overall time saving from dispatch to thrombolysis was 42.5 minutes (95% CI, 36.0–49.0). In the same period, 41 MSU patients received EVT (mean age, 76 years; 61% men) with median dispatch-to-treatment time saving of 51 minutes ([95% CI, 30.1–71.9], P <0.001). This included a median time saving of 17 minutes ([95% CI, 7.6–26.4], P =0.001) for EVT hospital arrival to arterial puncture for MSU patients. Estimated median disability-adjusted life years saved through earlier provision of reperfusion therapies were 20.9 for thrombolysis and 24.6 for EVT.

Conclusions—

The Melbourne MSU substantially reduced time to reperfusion therapies, with the greatest estimated disability avoidance driven by the more powerful impact of earlier EVT. These findings highlight the benefits of prehospital notification and direct triage to EVT centers with facilitated workflow on arrival by the MSU.

Cost-Consequence Analysis of Mobile Stroke Units vs. Standard Prehospital Care and Transport

Background: Mobile stroke units (MSUs) are the latest approach to improving time-sensitive stroke care delivery. Currently, there are no published studies looking at the expanded value of the MSU to diagnose and transport patients to the closest most appropriate facility. The purpose of this paper is to perform a cost consequence analysis of standard transport (ST) vs. MSU.

Methods and Results: A cost consequence analysis was undertaken within a decision framework to compare the incremental cost of care for patients with confirmed stroke that were served by the MSU vs. their simulated care had they been served by standard emergency medical services between July 2014 and October 2015. At baseline values, the incremental cost between MSU and ST was $70,613 ($856,482 vs. $785,869) for 355 patient transports. The MSU avoided 76 secondary interhospital transfers and 76 emergency department (ED) encounters. Sensitivity analysis identified six variables that had measurable impact on the model's variability and a threshold value at which MSU becomes the optimal strategy: number of stroke patients (>391), probability of requiring transfer to a comprehensive stroke center (CSC, >0.52), annual cost of MSU operations (<$696,053), cost of air transfer (>$8,841), probability initial receiving hospital is a CSC (<0.32), and probability of ischemic stroke with ST (<0.76).

Conclusions: MSUs can avert significant costs in the administration of stroke care once optimal thresholds are achieved. A comprehensive cost-effectiveness analysis is required to determine not just the operational value of an MSU but also its clinical value to patients and the society.

Mobile Stroke Units: Bringing Treatment to the Patient

PURPOSE OF REVIEW

Mobile stroke units (MSUs) have revolutionized emergency stroke care by delivering pre-hospital thrombolysis faster than conventional ambulance transport and in-hospital treatment. This review discusses the history of MSUs technological development, current operations and research, cost-effectiveness, and future directions.

RECENT FINDINGS

Multiple prospective and retrospective studies have shown that MSUs deliver acute ischemic stroke treatment with intravenous recombinant tissue plasminogen activator (IV r-tPA) approximately 30 min faster than conventional care. The 90-day modified Rankin Scores for patients who received IV r-tPA on the MSU compared to conventional care were not statistically different in the PHANTOM-S study. Two German studies suggest that the MSU model is cost-effective by reducing disability and improving adjusted quality-life years post-stroke. The ongoing BEST-MSU trial will be the first multicenter, randomized controlled study that will shed light on MSUs' impact on long-term neurologic outcomes and cost-effectiveness. MSUs are effective in reducing treatment times in acute ischemic stroke without increasing adverse events. MSUs could potentially improve treatment times in large vessel occlusion and intracranial hemorrhage. Further studies are needed to assess functional outcomes and cost-effectiveness. Clinical trials are ongoing internationally.

Geographic Analysis of Mobile Stroke Unit Treatment in a Dense Urban Area: The New York City METRONOME Registry

Background Mobile stroke units (MSUs) reduce time to intravenous thrombolysis in acute ischemic stroke. Whether this advantage exists in densely populated urban areas with many proximate hospitals is unclear. Methods and Results We evaluated patients from the METRONOME (Metropolitan New York Mobile Stroke) registry with suspected acute ischemic stroke who were transported by a bi-institutional MSU operating in Manhattan, New York, from October 2016 to September 2017. The comparison group included patients transported to our hospitals via conventional ambulance for acute ischemic stroke during the same hours of MSU operation (Monday to Friday, 9 am to 5 pm). Our exposure was MSU care, and our primary outcome was dispatch-to-thrombolysis time. We estimated mean differences in the primary outcome between both groups, adjusting for clinical, demographic, and geographic factors, including numbers of nearby designated stroke centers and population density. We identified 66 patients treated or transported by MSU and 19 patients transported by conventional ambulance. Patients receiving MSU care had significantly shorter dispatch-to-thrombolysis time than patients receiving conventional care (mean: 61.2 versus 91.6 minutes; P=0.001). Compared with patients receiving conventional care, patients receiving MSU care were significantly more likely to be picked up closer to a higher mean number of designated stroke centers in a 2.0-mile radius (4.8 versus 2.7, P=0.002). In multivariable analysis, MSU care was associated with a mean decrease in dispatch-to-thrombolysis time of 29.7 minutes (95% CI, 6.9-52.5) compared with conventional care. Conclusions In a densely populated urban area with a high number of intermediary stroke centers, MSU care was associated with substantially quicker time to thrombolysis compared with conventional ambulance care.

Googling Location for Operating Base of Mobile Stroke Unit in Metropolitan Sydney

Background and purpose: The recent advances in stroke therapy have placed focus on delivering care within the first hour after stroke onset (golden hour), principally through the use of Mobile Stroke Unit (MSU) to bring the hospital to the patient. The aim of this project is to search the location of MSU hub in Sydney, Australia, optimizing for catchment, transport to nearest thrombolysis and endovascular clot retrieval (ECR)/thrombectomy capable hospital and population at risk. Methods: Traveling time was performed using ggmap package in R to interface with Google Maps application program interface (API). This analysis estimates the travel time from the centroids of each suburbs to five potential MSU hubs (Royal Prince Alfred, Prince of Wales, Royal North Shore, Liverpool, and Westmead hospitals) and eight thrombolysis capable hospitals. It is proposed that the MSU should be deployed at ECR hub to cover the suburbs, not well-covered by thrombolysis and ECR capable hospitals. This step was performed by assigning membership to hospitals within 30 min traveling time to the ECR hub. The base hub of the MSU was proposed as the closest hub (providing ECR) to the least well-served suburbs. The population serviceable by MSU was estimated using stroke incidence studies in Melbourne and Adelaide. Results: The largest population, serviceable by MSU within 30 min (4,606 cases), 45 min radius (8,918 cases), and 60 min (10,084 cases), was Royal North Shore followed by Royal Prince Alfred, Liverpool, Westmead, and Prince of Wales hospitals. Prince of Wales hospital has the smallest catchment within 30 min (3,078 cases), 45 min (7,721 cases), and 60 min (9,984 cases). Suburbs at the edge of metropolitan Sydney such as the Northern Suburbs are less well-served by thrombolysis and ECR capable hospitals. There are 10 suburbs within 30 min travel of one hospital. The remainders are within 30 min of two or more hospitals. Conclusions: Any of the five endovascular clot retrieval capable hospitals are capable of serving as a hub for MSU. We provide a method to identify the hub based on location of suburbs less well-served by other hospital.

Googling Boundaries for Operating Mobile Stroke Unit for Stroke Codes

Background: Mobile stroke units (MSU) have been proposed to expedite delivery of recombinant tissue plasminogen activator (tPA) and expedite endovascular clot retrieval (ECR). Unexplored questions in the use of MSU include: maximal distance from base, time limit with regards to the use CT imaging, CT Angiography, CT Perfusion, and Telemedicine. We developed a computational model as an app (https://gntem3.shinyapps.io/ambmc/), taking into account traveling time to explore this issue. The aim of this study was to define the operating parameters for an MSU in a large metropolitan city, based on the geography of Melbourne.

Methods: There are 2 hospitals (Royal Melbourne Hospital/RMH, Monash Medical Center/MMC) designated to provide state-wide ECR services. In these spatial simulations, the MSU is based at RMH and delivers tPA at the patient's pick-up address and then takes the patient to the nearest ECR center. We extracted the geocode of suburbs in Melbourne and travel time to each hospital using ggmap, an interface to Google Map API. The app contains widgets for varying the processing time at the patient location (default = 30 min), performing CT angiography (default = 10 min), performing telemedicine consultation (default = 15 min). The data were compared against those for usual ambulance metrics (default traveling time = 15 min, processing time at patient's location = 20 min, door to tPA = 60 min, door to groin = 90 min). Varying the widgets allow the viewer to explore the trade-off between the variable of interest and time to therapy at a suburb level.

Results: The MSU was superior for delivering tPA to all Melbourne suburbs (up to 76 min from RMH). If the CTA times or processing time at location increased by 20 min then it was superior for providing ECR to only 74.9% of suburbs if the return base was RMH. Addition of CT Perfusion or telemedicine consultation affect the ability of a single hospital to provide ECR but not tPA if these additions can be limited to 20 min. Conclusion: The app can help to define how best to deploy the MSU across Melbourne. This app can be modified and used to optimize operating characteristics of MSU in other centers around the world.

Improving Prehospital Stroke Services in Rural and Underserved Settings With Mobile Stroke Units

In acute stroke management, time is brain, as narrow therapeutic windows for both intravenous thrombolysis and mechanical thrombectomy depend on expedient and specialized treatment. In rural settings, patients are often far from specialized treatment centers. Concurrently, financial constraints, cutting of services and understaffing of specialists for many rural hospitals have resulted in many patients being underserved. Mobile Stroke Units (MSU) provide a valuable prehospital resource to rural and remote settings where patients may not have easy access to in-hospital stroke care. In addition to standard ambulance equipment, the MSU is equipped with the necessary tools for diagnosis and treatment of acute stroke or similar emergencies at the emergency site. The MSU strategy has proven to be effective at facilitating time-saving stroke triage decisions. The additional on-board imaging helps to determine whether a patient should be taken to a primary stroke center (PSC) for standard treatment or to a comprehensive stroke center (CSC) for advanced stroke treatment (such as intra-arterial therapy) instead. Diagnosis at the emergency site may prevent additional in-hospital delays in workup, handover and secondary (inter-hospital) transport. MSUs may be adapted to local needs-especially in rural and remote settings-with adjustments in staffing, ambulance configuration, and transport models. Further, with advanced imaging and further diagnostic capabilities, MSUs provide a valuable platform for telemedicine (teleradiology and telestroke) in these underserved areas. As MSU programmes continue to be implemented across the world, optimal and adaptable configurations could be explored.

Air-Mobile Stroke Unit for access to stroke treatment in rural regions

Background

In recent years, important progress has been made in effective stroke treatment, however, patients living in rural and remote areas have nil or very limited access to timely reperfusion therapies.

Aims

Novel systems of care to overcome the detrimental treatment gap for stroke patients living in rural and remote regions need to be developed.

Summary of review

A possible solution to the treatment disparity between stroke patients living in metropolitan and rural areas may involve the use of specially designed aircrafts equipped with the ability to diagnose and treat acute stroke at remote emergency sites. We describe technical solutions for an Air-Mobile Stroke Unit (Air-MSU) concept, where an aircraft is customized with the ability to perform multimodal computed tomography, in addition to onboard laboratory equipment and telemedicine connection. The Air-MSU is envisioned not only to allow intravenous thrombolysis in the field but also to allow prehospital triage to a comprehensive stroke center through use of contrast intracerebral vascular imaging. Several options for the Air-MSU approach are described, and issues regarding the potential medical benefit, optimal operating environment, technical realization, and integration in pre-existing solutions (e.g., flying doctor service) are addressed.

Conclusion

The Air-MSU may represent a novel tool to reduce treatment disparity for stroke patients in rural and remote areas. However, this approach requires further implementation research to determine the overall benefit to these communities.

Update in the Early Management and Reperfusion Strategies of Patients with Acute Ischemic Stroke

Acute ischemic stroke (AIS) remains a leading cause of death and long-term disability. The paradigms on prehospital care, reperfusion therapies, and postreperfusion management of patients with AIS continue to evolve. After the publication of pivotal clinical trials, endovascular thrombectomy has become part of the standard of care in selected cases of AIS since 2015. New stroke guidelines have been recently published, and the time window for mechanical thrombectomy has now been extended up to 24 hours. This review aims to provide a focused up-to-date review for the early management of adult patients with AIS and introduce the new upcoming areas of ongoing research.

Review of the Mobile Stroke Unit Experience Worldwide

Background

The treatment of stroke is dependent on a narrow therapeutic time window that requires interventions to be emergently pursued. Despite recent "FAST" initiatives that have underscored "time is brain," many patients still fail to present within the narrow time window to receive maximum treatment benefit from advanced stroke therapies, including recombinant tissue plasminogen activator (tPA) and mechanical thrombectomy. The convergence of emergency medical services, telemedicine, and mobile technology, including transportable computed tomography scanners, has presented a unique opportunity to advance patient stroke care in the prehospital field by shortening time to hyperacute stroke treatment with a mobile stroke unit (MSU).

Summary

In this review, we provide a look at the evolution of the MSU into its current status as well as future directions. Our summary statement includes historical and implementation information, economic cost, and published clinical outcome and time metrics, including the utilization rate of thrombolysis.

Key Messages

Initially hypothesized in 2003, the first MSUs were launched in Germany and adopted worldwide in acute, prehospital stroke management. These specialized ambulances have made the diagnosis and treatment of many neurological emergencies, in addition to ischemic and hemorrhagic stroke, possible at the emergency site. Providing treatment as early as possible, including within the prehospital phase of stroke management, improves patient outcomes. As MSUs continue to collect data and improve their methods, shortened time metrics are expected, resulting in more patients who will benefit from faster treatment of their acute neurological emergencies in the prehospital field.