"Activity Matters was great - I now realize: if I move, I'm fitter.": development and process evaluation of a web-based program for persons with multiple sclerosis

PURPOSE

Research shows that persons with mild to moderate multiple sclerosis are less physically active than healthy controls even though they would benefit from it. This study focusses on the feasibility testing and process evaluation of the pilot study of Activity Matters, a twelve-week web-based program, from Ireland, to increase physical activity in this population.

MATERIALS AND METHODS

The intervention was adapted to local circumstances in Hamburg, Germany and consists of eleven modules incorporating behavior change techniques. After feasibility had been confirmed, 43 persons with multiple sclerosis participated in a pilot study with a pre-post, single-group intervention design. Qualitative data was collected with questionnaires and semi structured interviews. Physical activity level and stage of change was measured quantitatively.

RESULTS

Participants had a mean age of 49.5 years (SD 9.29) and an average Patient Determined Disease Step Score of 2.2 (SD 1.47). Thirty-six participants answered the follow-up questionnaire. On average 9.8 modules were processed within 13 weeks. Each tool for behavior change was perceived as helpful except the chat group. Physical activity levels increased significantly from pre- to post intervention (p-value 0.042, Cohen's d = 0.35).

CONCLUSIONS

The results indicate that Activity Matters is feasible and satisfactory and may change activity levels.

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.

Interdisciplinary interactions, social systems and technical infrastructure required for successful implementation of mobile stroke units: A qualitative process evaluation

RATIONALE

Mobile stroke units (MSUs) are increasingly being implemented to provide acute stroke care in the prehospital environment, but a comprehensive implementation evaluation has not been undertaken.

AIM

To identify successes and challenges in the pre- and initial operations of the first Australian MSU service from an interdisciplinary perspective.

METHODS

Process evaluation of the Melbourne MSU with a mixed-methods design. Purposive sampling targeted key stakeholder groups. Online surveys (administered June-September 2019) and semistructured interviews (October-November 2019) explored experiences. Directed content analysis (raters' agreement 85%) and thematic analysis results are presented using the Interactive Sociotechnical Analysis framework.

RESULTS

Participants representing executive/program operations, MSU clinicians and hospital-based clinicians completed 135 surveys and 38 interviews. Results converged, with major themes addressing successes and challenges: stakeholders, vehicle, knowledge, training/education, communication, work processes and working relationships.

CONCLUSIONS

Successes and challenges of establishing a new MSU service extend beyond technical, to include operational and social aspects across prehospital and hospital environments.

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.

Abstract TMP54: Increased Thrombectomy Time Saving From Melbourne Mobile Stroke Unit Operation During Covid-19 Pandemic

Introduction: Mobile stroke units (MSU) have demonstrated major time savings for thrombolysis but mixed evidence for endovascular thrombectomy (EVT). COVID-19 precautions have dramatically slowed EVT workflows across Australia and we therefore aimed to examine the effect of the Melbourne MSU on thrombectomy times before and during the current pandemic.

Methods: Patients receiving EVT facilitated by the Melbourne MSU from 2017-2021 were compared to non-MSU patients (metropolitan direct and secondary transfer for EVT) admitted to the largest Melbourne EVT centre. Quantile regression analysis was used to calculate the median time difference (50 th quantile) between MSU and non-MSU patients before and during the pandemic, grouped by patients within an EVT centre ambulance catchment or those outside (who either received inter-hospital transfer or MSU-facilitated bypass to an EVT centre).

Results: A total of 402 patients (112 MSU) were included. Pre-pandemic, no reduction in dispatch to arterial access time was seen for MSU patients within an EVT centre catchment (median 11min slower, p=0.38). However, a significant time saving was observed during the pandemic (median 29 min faster, p<0.001, p-interaction=0.0065). MSU care reduced hospital arrival to arterial access time by median 19min pre-pandemic vs 40 min during the pandemic, p-interaction<0.001). The pandemic did not alter MSU-related time savings for patients located outside of an EVT centre catchment.

Conclusions: Melbourne MSU facilitation of EVT during the COVID-19 pandemic resulted in greater time savings for patients located close to a thrombectomy centre, while substantial time savings were maintained for those needing bypass from the local non-EVT hospital. This suggests that MSU operation enables streamlined EVT workflows during the pandemic by providing early pre-hospital notification and interventional angiography activation.

Abstract WMP47: Low Sensitivity Of Widely Used Emergency Dispatch Algorithm For Thrombectomy Patients - Implications For Mobile Stroke Units

Introduction: Widely used emergency dispatch algorithms such as the Advanced Medical Priority Dispatch System (AMPDS) have limited diagnostic accuracy for prehospital diagnosis of stroke. With advent of mobile stroke units (MSU), this inaccuracy prevents optimal dispatch to patients who may benefit. Expedited endovascular thrombectomy (EVT) is a major contributor to net benefit of MSUs. We assessed the accuracy of AMPDS for recognizing stroke in thrombectomy patients in the Australian state of Victoria.

Methods: We included consecutive patients accepted for EVT (direct and secondary transfer) to The Royal Melbourne Hospital from 2007-2021 in whom linked AMPDS dispatch codes could be obtained from Ambulance Victoria. The primary outcome was the proportion of cases dispatched as stroke vs non-stroke with subgroup analyses of the effect of baseline clinical severity, metropolitan vs rural dispatch and time to thrombectomy. Chi square and Mann Whitney tests were used as appropriate.

Results: A total of n=618 patients were included with baseline NIHSS 16 (IQR 10-20). Of these, only 62% (95% CI 58-66) were initially dispatched as suspected stroke, with the most common non-stroke diagnoses being “Unconscious/Fainting” (19.2%) and “Falls” (6.9%). Those with a higher baseline severity (NIHSS ≥10) were less likely to be classified as stroke than those with lower severity (59% vs 76%, p<0.001), while no difference was found between metropolitan and rural patients (p=0.066). Overall, no significant time differences were found between stroke and non-stroke dispatches for ambulance dispatch to arterial access (median 208 vs 216 min, p=0.593) or hospital arrival to arterial access (median 42 vs 42 min, p=0.851). However, only 32 patients were treated on the MSU, which commenced operation November 2017.

Conclusions: Almost 40% of thrombectomy patients did not receive an initial AMPDS dispatch of suspected stroke and those with higher baseline severity were more likely to be misclassified. Although time to thrombectomy was not significantly different between stroke vs non-stroke dispatches, MSU treatment was under-represented. Our findings have implications for emergency medical services and particularly mobile stroke units which rely on accurate stroke dispatch.

Tenecteplase versus Alteplase for Stroke Thrombolysis Evaluation Trial in the Ambulance (Mobile Stroke Unit-TASTE-A): protocol for a prospective randomised, open-label, blinded endpoint, phase II superiority trial of tenecteplase versus alteplase for ischaemic stroke patients presenting within 4.5 hours of symptom onset to the mobile stroke unit

INTRODUCTION

Mobile stroke units (MSUs) equipped with a CT scanner are increasingly being used to assess and treat stroke patients' prehospital with thrombolysis and transfer them to the most appropriate hospital for ongoing stroke care and thrombectomy when indicated. The effect of MSUs in both reducing the time to reperfusion treatment and improving patient outcomes is now established. There is now an opportunity to improve the efficacy of treatment provided by the MSU. Tenecteplase is a potent plasminogen activator, which may have benefits over the standard of care stroke lytic alteplase. Specifically, in the MSU environment tenecteplase presents practical benefits since it is given as a single bolus and does not require an infusion over an hour like alteplase.

OBJECTIVE

In this trial, we seek to investigate if tenecteplase, given to patients with acute ischaemic stroke as diagnosed on the MSU, improves the rate of early reperfusion.

METHODS AND ANALYSIS

TASTE-A is a prospective, randomised, open-label, blinded endpoint (PROBE) phase II trial of patients who had an ischaemic stroke assessed in an MSU within 4.5 hours of symptom onset. The primary endpoint is early reperfusion measured by the post-lysis volume of the CT perfusion lesion performed immediately after hospital arrival.

ETHICS AND DISSEMINATION

The study was approved by the Royal Melbourne Hospital Human Ethics committee. The findings will be published in peer-reviewed journals, presented at academic conferences and disseminated among consumer and healthcare professional audiences.

TRIAL REGISTRATION NUMBER

NCT04071613.

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.

Understanding Coordinator Roles in Acute Stroke Care: A National Survey

OBJECTIVES

Coordinators contribute to stroke care quality. Evidence on the scope of practice of coordinator roles for stroke is lacking. We aimed to survey Australian stroke coordinators and describe their responsibilities and characteristics, and compare these based on perceived competency.

MATERIALS AND METHODS

Online survey of non-physician coordinators with a clinical leadership position for acute stroke in Australian hospitals. Participants were identified from the Stroke Foundation National Audit, and advertising via national associations/networks. Quantitative data were analysed descriptively; characteristics and responsibilities assessed by Benner's self-perceived competency (novice/advanced beginner/competent, proficient or expert). Inductive thematic analysis was used for open-ended responses.

RESULTS

Results from 105/141 coordinators (103 hospitals, 90% female, 90% registered nurses). Two-thirds developed the role/were self-taught, with 36% using the 'stroke coordinator' title. Perceived competency varied; 22% expert, 40% proficient, and 33% competent. A variety of important clinical tasks, along with leadership/management, education and research responsibilities were described. Most frequently reported clinical responsibility was discharge planning (77%), with patient and staff education (85% and 88%), and data collection (94%) common. Compared to those reporting lesser competency, 'experts' had greater involvement in outpatient clinics (50% vs 14%) and leadership/management responsibilities (e.g. local hospital committees 77% vs 46%). 'Knowledge of evidence' and 'empowering others' were important characteristics to 'expert' coordinators.

CONCLUSIONS

A contemporary understanding of important responsibilities and characteristics of acute stroke coordinators are provided. Perceived competency affected scope of practice. Structured education, training and role delineation is warranted to improve competency. Career development of stroke coordinators is urgently needed to support optimal role performance.

Mobile Stroke Units Facilitate Prehospital Management of Intracerebral Hemorrhage

BACKGROUND AND PURPOSE

Mobile stroke units (MSUs) improve reperfusion therapy times in acute ischemic stroke (AIS). However, prehospital management options for intracerebral hemorrhage (ICH) are less established. We describe the initial Melbourne MSU experience in ICH.

METHODS

Consecutive patients with ICH and AIS treated by the Melbourne MSU were included. We describe demographics, proportions of patients receiving specific therapies, and bypass to comprehensive/neurosurgical centers. We also compare operational time metrics between patients with MSU-ICH and MSU-AIS.

RESULTS

During a 2-year period, the Melbourne MSU managed 49 patients with ICH, mean (SD) age 74 (12) years, median (interquartile range) National Institutes of Health Stroke Scale 17 (12-20). Intravenous antihypertensives were the commonest treatment provided (46.9%). Bypass of a primary center to a comprehensive center with neurosurgical expertise occurred in 32.7% of patients with MSU-ICH compared with 20.5% of patients with MSU-AIS. Compared with patients with MSU-AIS, patients with MSU-ICH had faster onset-to-emergency-call, and onset-to-scene-arrival times at the median and 75th percentiles.

CONCLUSIONS

MSUs can facilitate ultra-early ICH diagnosis, management, and triage.

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.

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.

Abstract 96: Greater Clinical Impact of Thrombectomy Compared to Thrombolysis in First Year of Melbourne Mobile Stroke Unit Operation

Introduction: The role of mobile stroke units (MSU) in earlier provision of thrombolysis (tPA) is well described, but the effect on endovascular thrombectomy (EVT) is less clear. Despite the theoretical advantages of improved triage and prehospital activation of EVT services, only a small effect on hospital arrival to EVT start has so far been described. We aimed to analyze the clinical benefit of EVT and tPA from operation of the Melbourne MSU in the first year.

Methods: First ambulance dispatch to reperfusion treatment commencement (DTT) times between MSU patients receiving reperfusion therapy from November 2017-18 were compared to consecutive control cases during MSU operating hours presenting across metropolitan Melbourne for tPA, and direct and metropolitan transfer patients presenting to the Royal Melbourne Hospital for EVT. Median time difference between MSU and controls was regarded as the 50 th quantile using quantile regression analysis. Comparative disability avoidance was estimated for EVT and tPA using calculated time savings.

Results: In the first calendar year, the MSU operated for 30.5 service (7-day) weeks. Prehospital tPA was administered to 52 patients, with median time differences for dispatch-to-hospital/scene-arrival of -30 minutes (p<0.0001) and arrival-to-tPA of -17 minutes (p=0.001), resulting in overall DTT time saving of 47 minutes compared to controls. In the same timeframe, 26 patients received EVT with median time difference of -51 minutes (p<0.0001) compared to controls. Prehospital notification resulted in median time difference of -17 minutes (p=0.001) for EVT center-arrival to groin puncture. Using published estimates of disability avoidance per minute of time saved for each reperfusion therapy, the clinical impact of the EVT time saving for the 26 MSU patients is equivalent to the clinical impact of 67 tPA patients treated on the MSU.

Conclusion: The clinical impact of Melbourne MSU operation on earlier provision of EVT was greater than that of tPA in the first year of operation, reflecting facilitated triage to EVT centers and early prehospital notification. In locales where EVT capability is limited or unevenly distributed such as Melbourne, facilitation of EVT is likely to be a central driver of MSU operation.

Abstract WP275: Potential Cost Effectiveness of the Melbourne Mobile Stroke Unit

Background: Mobile stroke units (MSUs) are ambulances with brain scanning capability and specialised staff. In Australia, the first MSU was launched in Melbourne, November 2017. The Melbourne MSU has two paramedics, a radiographer, a stroke neurologist and a stroke nurse specialist (5 days per week/ 8am-6pm). The MSU is co-dispatched with a standard ambulance to a patient with suspected stroke within metropolitan Melbourne (20km radius). In cases where the standard ambulance assessed the patient first and stroke is eliminated, the MSU is contacted to ‘stand-down’. The cost-effectiveness of this type of ‘pre-hospital’ service remains unclear.

Methods: The potential cost-effectiveness of the Melbourne MSU was estimated for 2018 following the pilot period (Nov-Dec 2017). A simulation model was developed for 2018 with a) program costs: operational/finance reports, self-report program leads/senior operational staff; b) clinical processes: MSU medical records/historical data; and c) health effects of treatment taken from the literature for reperfusion therapies to patients with ischaemic stroke (i.e. benefits: additional patients treated/faster treatment). Primary outcome: incremental cost per disability adjusted life year (DALY) avoided. The comparison was to standard pre-hospital and emergency department historical ‘usual’ care. Probabilistic, multivariable uncertainty analyses with Monte Carlo (10,000) simulations and sensitivity analyses were conducted.

Results: In 2018, the Melbourne MSU was dispatched for 1244 suspected strokes (200 operational days). Overall, 46.9 DALYs were potentially avoided (95% uncertainty interval 33.02, 82.15 DALYs). The net cost of operating the MSU was ~$US 980,000, and the incremental cost/DALY avoided was $US 20,681 compared to standard care (95% uncertainty interval $US 14,167, $US 32,214).

Conclusion: The Melbourne MSU is a cost-effective model for stroke care based on a standard willingness-to-pay cost-effectiveness threshold (<$US 50,000 per DALY avoided). Future adaptations to the operational model may improve the cost-effectiveness of this service.

011 Melbourne mobile stroke unit halves workflow for acute stroke reperfusion therapy

Background

The Melbourne Mobile Stroke Unit (MSU) utilises a specialised ambulance with on-board CT scanner and multidisciplinary team to provide on-scene imaging, treatment and triage for central Melbourne, Australia. We describe the operational impact of the MSU on commencement of acute reperfusion therapy.

Methods

Data from the first 12 months of operation were collected for all patients receiving reperfusion therapy from November 2017. Workflow times were compared to contemporary published Australian data and historical controls from Royal Melbourne Hospital.

Results

In the first calendar 12 months of operation, the Melbourne MSU operated 30.5 service weeks and provided prehospital thrombolysis (tPA) to n=52 patients (44% of eligible infarcts) and directed n=33 patients for endovascular thrombectomy, of which 48% required bypass from the closest non-thrombectomy hospital. The overall median onset-to-tPA for MSU patients was 97.5 mins compared to the Australian metropolitan median of 150 mins. Thrombolysis in the first ‘golden hour’ increased to 13.5% from 3.3% in-hospital. Median onset-to-groin for MSU patients receiving EVT was 162 mins compared to 234 mins from historical controls.

Discussion

Prehospital treatment and triage using the Mobile Stroke Unit in metropolitan Melbourne resulted in substantial improvements in commencement of reperfusion therapy. Workflow times are approximately halved for thrombolysis and endovascular thrombectomy respectively. Prehospital thrombolysis also allowed a >400% increase in the proportion of treatment in the first ‘golden hour’.

Abstract TP291: Melbourne Mobile Stroke Unit Increases Stroke Treatment Rates and Treatment Opportunities

Background: The Melbourne Mobile Stroke Unit (MSU) is the first stroke ambulance in Australia. The MSU aims to provide rapid access to time critical treatments to acute stroke patients in the pre-hospital setting, thereby increasing the number of patients eligible for treatment. This is achieved by providing immediate access to expert stroke and ambulance personnel and the use of a mobile CT scanner.

Methods: Data are prospectively collected on all MSU dispatches and compared to our local hospital database and Australian national standards.

Results: The Melbourne MSU launched November 20 th 2017. It has been dispatched to 970 cases, of which 400 patients (41%) were attended by the MSU. Forty-two patients were thrombolysed (28% of all ischemic stroke versus the Australian average of 13% in-hospital thrombolysis), with a median scene-needle time of 40 mins (23-80mins). The median Australian door-needle time is 72 mins, with only 30% of patients treated within the internationally recommended 60 mins. Of the MSU thrombolysed patients, 12% were treated 3.5-4.5 hours from symptom onset; given ambulance transport and standard door-to-needle times, these patients would have been excluded from hospital-based lysis due to time. Additionally, the number of “golden hour” (onset-needle <60mins) thrombolysis patients has increased from 2% within our hospital to 12% on the MSU. Three patients had their anticoagulation reversed on the MSU with idarucizumab prior to thrombolysis and 1 patient received prothrombinex to manage a warfarin-related ICH. Nicardipine, labetalol and hydralazine are routinely used to manage BP. The MSU also provides a unique platform for hyperacute research trials, enrolling 10 patients into both ischemic and hemorrhagic stroke trials (utilising tenecteplase and tranexamic acid respectively).

Conclusion: The Melbourne MSU more than doubles the rate of thrombolysis compared to in-hospital treatment and provides a comprehensive range of other novel treatments and opportunities. Consequently, the MSU allows more patients to be treated than the standard ambulance-hospital paradigm.

Abstract 175: Faster Prehospital Workflow in the Melbourne Mobile Stroke Unit Halves Onset to Reperfusion Therapy

Background: The Melbourne Mobile Stroke Unit (MSU) utilises a specialised ambulance with on-board CT scanner and multidisciplinary team to provide on-scene imaging, treatment and triage for central Melbourne, Australia. We describe the operational impact of the MSU on stroke onset to treatment time for acute reperfusion therapy.

Methods: Data from the first 6 months of operation were collected for all patients receiving reperfusion therapy from November 2017. Workflow times were compared to contemporary published Australian data and ambulance travel times were derived using a validated Google Maps algorithm.

Results: In the first 6 months of operation, the Melbourne MSU provided prehospital thrombolysis (tPA) to n=28 patients (39% of ischemic stroke<4.5h) and directed n=17 patients (24% of infarcts <6hrs) for endovascular thrombectomy (EVT), of which 6/17 (35%) required bypass of the closest non-EVT hospital. Figure 1 shows workflow times for thrombolysis and thrombectomy bypass compared to historical controls. The overall median onset-to-tPA for MSU patients was 101 mins compared to the Australian metropolitan median of 150 mins. Despite a median travel time of 15 mins to the nearest stroke centre, the calculated time saving to start of tPA was 30-60 mins. Prehospital notification for EVT allowed median hospital arrival-to-groin puncture time of 33 mins compared to historical values of 54 mins. MSU diagnosis and bypass to an EVT hospital conservatively reduced EVT delay by 60-90 mins.

Discussion: Prehospital treatment and triage using the Mobile Stroke Unit in metropolitan Melbourne resulted in substantially faster commencement of reperfusion therapy. First medical contact to treatment times were approximately halved for thrombolysis and patients requiring bypass for endovascular thrombectomy. Future research will determine the effect of earlier treatment on patient outcomes and cost-effectiveness analysis.

Reliability of the Acutely Estimated Premorbid Modified Rankin Scale for Stroke Treatment Decision Making

BACKGROUND

Premorbid functional status is an important factor in acute stroke treatment decision making. Determining the modified Rankin Score (mRS) accurately may be difficult due to deficits from stroke and lack of collateral information in the acute setting. Data on the reliability of the premorbid mRS in "real-world" practice outside of clinical trial or registry settings are limited.

METHODS

A retrospective study at a high volume academic primary stroke center. For patients with acute ischemic stroke treated with alteplase between July 2012 and July 2016, hospital electronic records were reviewed for detailed inpatient occupational therapist (OT) assessment of premorbid functional status to determine mRS (OT-mRS). This was compared with premorbid mRS determined at acute emergency department assessment (Acute-mRS). Kappa statistic and Lin's concordance correlation coefficient was used to calculate agreement between Acute-mRS and OT-mRS.

RESULTS

Among stroke patients treated with alteplase over the 4 years period, OT-mRS was available for 312 patients (79.0%), the mean age was 75.5 years (male 51.9%). 82.4%, 11.9%, and 5.8% of patients had Acute-mRS of 0-1, 2, and ≥3; while 84.9%, 8.0%, and 6.7% had OT-mRS of 0-1, 2, and ≥3, respectively. The agreement between Acute-mRS and OT-mRS was 83.3%, with κ = .64 and correlation coefficient r = .87 (95% CI .841-.896, P < .05).

CONCLUSIONS

There was at least moderate agreement between Acute-mRS prior to thrombolysis and OT-mRS obtained by detailed assessment later. The number of patients with premorbid disability was small and may have positively influenced the agreement between the 2 scores.

Prehospital idarucizumab prior to intravenous thrombolysis in a mobile stroke unit

Background

Administration of intravenous idarucizumab to reverse dabigatran anticoagulation prior to thrombolysis for patients with acute ischemic stroke has been previously described, but not in the prehospital setting. The speed and predictability of idarucizumab reversal is well suited to prehospital treatment in a mobile stroke unit and allows patients with recent dabigatran intake to access reperfusion therapy.

Aims

To describe feasibility of prehospital idarucizumab administration prior to thrombolysis on the Melbourne mobile stroke unit.

Methods

The Melbourne mobile stroke unit is a specialized stroke ambulance servicing central metropolitan Melbourne, Australia and provides prehospital assessment, scanning and treatment with an integrated CT scanner and multidisciplinary stroke team. All cases were identified through the mobile stroke unit treatment registry since launch in November 2017.

Results

Of a total of n = 20 thrombolysis cases in the first 4 months of operation, three patients (15%) received intravenous idarucizumab 5 g for dabigatran reversal prior to thrombolysis. Mean time between idarucizumab administration and thrombolysis was approximately 10 minutes. Two of the three patients were shown to have large vessel occlusion on CTA in the mobile stroke unit and proceeded to endovascular thrombectomy. At 24 hours, only one patient had a small amount of asymptomatic petechial hemorrhage on follow-up imaging. All patients demonstrated substantial neurological recovery and were discharged to inpatient rehabilitation.

Conclusions

Rapid treatment with prehospital administration of idarucizumab prior to thrombolysis using a mobile stroke unit is feasible and facilitates hyperacute treatment.

Large Vessel Occlusion Scales Increase Delivery to Endovascular Centers Without Excessive Harm From Misclassifications

Background and Purpose—

Clinical large vessel occlusion (LVO) triage scales were developed to identify and bypass LVO to endovascular centers. However, there are concerns that scale misclassification of patients may cause excessive harm. We studied the settings where misclassifications were likely to occur and the consequences of these misclassifications in a representative stroke population.

Methods—

Prospective data were collected from consecutive ambulance-initiated stroke alerts at 2 stroke centers, with patients stratified into typical (LVO with predefined severe syndrome and non-LVO without) or atypical presentations (opposite situations). Five scales (Rapid Arterial Occlusion Evaluation [RACE], Los Angeles Motor Scale [LAMS], Field Assessment Stroke Triage for Emergency Destination [FAST-ED], Prehospital Acute Stroke Severity scale [PASS], and Cincinnati Prehospital Stroke Severity Scale [CPSSS]) were derived from the baseline National Institutes of Health Stroke Scale scored by doctors and analyzed for diagnostic performance compared with imaging.

Results—

Of a total of 565 patients, atypical presentations occurred in 31 LVO (38% of LVO) and 50 non-LVO cases (10%). Most scales correctly identified >95% of typical presentations but <20% of atypical presentations. Misclassification attributable to atypical presentations would have resulted in 4 M1/internal carotid artery occlusions, with National Institutes of Health Stroke Scale score ≥6 (5% of LVO) being missed and 9 non-LVO infarcts (5%) bypassing the nearest thrombolysis center.

Conclusions—

Atypical presentations accounted for the bulk of scale misclassifications, but the majority of these misclassifications were not detrimental, and use of LVO scales would significantly increase timely delivery to endovascular centers, with only a small proportion of non-LVO infarcts bypassing the nearest thrombolysis center. Our findings, however, would require paramedics to score as accurately as doctors, and this translation is made difficult by weaknesses in current scales that need to be addressed before widespread adoption.

Abstract TMP63: Large Vessel Occlusion Triage Scales Struggle With Atypical Presentations but Misclassifications Are Rarely Detrimental

Introduction: Large vessel occlusion (LVO) triage scales aim to identify LVO on clinical grounds and direct ambulances to endovascular centers, but current tools are reported to have poor performance in independent datasets. We investigated situations where these tools were performing poorly and examined the possible impacts of misclassification.

Methodology: Patient data were collected prospectively from consecutive ambulance initiated stroke codes at two major stroke centers. Patients with symptom onset >6 hours and pre-existing deficits were excluded. LVO was defined as ICA, M1 or proximal M2 occlusion on CT angiography. National Institutes of Health Stroke Scale (NIHSS) scores assessed by stroke clinicians were used to derive five published triage tools (RACE, LAMS, CPSSS, PASS, FAST-ED). Patients were classified as 1) Typical presentations where LVO presented with severe symptoms (weakness and cortical sign) and non-LVO did not, or 2) Atypical presentations where non-LVO had severe symptoms and LVO did not.

Results: A total of 391 patients were included, of whom 59 were atypical presentations which included 25 ICH and 5 mimics. Most triage tools were able to correctly identify >95% of typical presentations but only 10-25% of atypical presentations. Within the atypical cases, bypassing the nearest stroke center would have delayed tPA for 6 patients (3.5% of all infarcts) with non-LVO infarcts. Conversely, of the missed LVO cases 10 patients (19.6% of all LVO) would have been immediately eligible for endovascular therapy. A further 6 M2 occlusions with NIHSS <6 would have been missed but were unlikely to have received intervention due to mild severity.

Conclusion: Misclassification by LVO triage tools is largely due to ICH and the uncommon situations where presence of LVO does not correspond to a severe clinical syndrome (and vice versa). Inaccuracies however, would have resulted in relatively few potential tPA patients bypassing the nearest center. Whilst a small proportion of LVO will be missed, overall delivery of LVO to endovascular centers will still be dramatically increased. LVO triage tools therefore have excellent potential to expedite endovascular treatment, but efforts are needed to improve prehospital paramedic accuracy to achieve this goal.

Predictors of the physical impact of Multiple Sclerosis following community-based, exercise trial

Background:

Studies evaluating exercise interventions in people with multiple sclerosis (PwMS) demonstrate small to medium positive effects and large variability on a number of outcome measures. No study to date has tried to explain this variability.

Objective:

This paper presents a novel exploration of data examining the predictors of outcome for PwMS with minimal gait impairment following a randomised, controlled trial evaluating community-based exercise interventions ( N = 242).

Methods:

The primary variable was the physical component of the Multiple Sclerosis Impact Scale-29, version 2 (MSIS-29, v2) after a 10-week, controlled intervention period. Predictors were identified a priori and were measured at baseline. Multiple linear regression was conducted.

Results:

Four models are presented lower MSIS-29, v2 scores after the intervention period were best predicted by a lower baseline MSIS-29,v2, a lower baseline Modified Fatigue Impact Score (physical subscale), randomisation to an exercise intervention, a longer baseline walking distance measured by the Six Minute Walk Test and female gender. This model explained 57.4% of the variance (F (5, 211) = 59.24, p < 0.01).

Conclusion:

These results suggest that fatigue and walking distance at baseline contribute significantly to predicting MSIS-29, v29 (physical component) after intervention, and thus should be the focus of intervention and assessment. Exercise is an important contributor to minimising the physical impact of MS, and gender-specific interventions may be warranted.

Abstract W P177: Direct to CT: Overcoming Barriers to Reduce Door to Needle times in Acute Stroke Patients

Background: Taking acute stroke patients direct from triage to the CT scanner can reduce thrombolysis treatment times, which can improve patient outcomes. In May 2013, Box Hill Hospital introduced a Direct to CT policy for acute stroke patients who are called through as a Code Stroke by the ambulance service within business hours (8am-4.30pm) Monday to Friday.

Method: We performed a prospective study comparing door-to-CT times (DTCT) and door-to-needle (DTN) times pre- and post-implementation of Direct to CT, and examined patient characteristics, Emergency Department (ED) presentation time, adverse effects, protocol violations and patient outcomes. Delays in treatment, enablers and barriers to treatment were also examined.

Results: There was no statistical difference in demographics or clinical factors in patients who presented pre- (January-April, n=21) or post- Direct to CT (May-July, n=29). However, a reduction in median DTCT times (27 mins vs. 16 mins, p=0.01) and DTN times (97 mins vs. 52 mins, p<0.001) was seen. There was no increase in thrombolysed mimics (4.8% vs. 3.4%, p=0.82), protocol violations (9.5% vs. 0%, p=0.17) or adverse outcomes (33% vs. 35%, p=0.93) in patients taken Direct to CT. There was no difference in patient outcomes, however the current study size is small. Numerous barriers to Direct to CT were identified within four categories: pre-hospital, ED, CT and the stroke team, and issues included: lack of paramedic intravenous cannulation, ED resources, and stroke team indecisions; some of which are ongoing and are taking considerable time and efforts to overcome.

Conclusions: Taking patients Direct to CT has significantly reduced time to treatment and further improvements may be achieved through resolution of identified barriers.

Validation of the DRAGON Score in 12 Stroke Centers in Anterior and Posterior Circulation

Background and Purpose—

The DRAGON score predicts functional outcome in the hyperacute phase of intravenous thrombolysis treatment of ischemic stroke patients. We aimed to validate the score in a large multicenter cohort in anterior and posterior circulation.

Methods—

Prospectively collected data of consecutive ischemic stroke patients who received intravenous thrombolysis in 12 stroke centers were merged (n=5471). We excluded patients lacking data necessary to calculate the score and patients with missing 3-month modified Rankin scale scores. The final cohort comprised 4519 eligible patients. We assessed the performance of the DRAGON score with area under the receiver operating characteristic curve in the whole cohort for both good (modified Rankin scale score, 0–2) and miserable (modified Rankin scale score, 5–6) outcomes.

Results—

Area under the receiver operating characteristic curve was 0.84 (0.82–0.85) for miserable outcome and 0.82 (0.80–0.83) for good outcome. Proportions of patients with good outcome were 96%, 93%, 78%, and 0% for 0 to 1, 2, 3, and 8 to 10 score points, respectively. Proportions of patients with miserable outcome were 0%, 2%, 4%, 89%, and 97% for 0 to 1, 2, 3, 8, and 9 to 10 points, respectively. When tested separately for anterior and posterior circulation, there was no difference in performance ( P =0.55); areas under the receiver operating characteristic curve were 0.84 (0.83–0.86) and 0.82 (0.78–0.87), respectively. No sex-related difference in performance was observed ( P =0.25).

Conclusions—

The DRAGON score showed very good performance in the large merged cohort in both anterior and posterior circulation strokes. The DRAGON score provides rapid estimation of patient prognosis and supports clinical decision-making in the hyperacute phase of stroke care (eg, when invasive add-on strategies are considered).

Abstract TP251: The Direct and Indirect Impact of the Acute Stroke Nurse Role on Thrombolysis Treatment Times and Rates

Background: The Acute Stroke Nurse (ASN) role at Box Hill Hospital is a business hours (weekday 8am - 4.30pm) first responder role designed to fast track acute stroke patients through thrombolysis screening in the Emergency Department. Since 2004, this role has been filled in either a full-time (FT) or part-time (PT) capacity, except for a 5-month period in 2010 where the role was vacant. We sought to explore the influence of having a full-time ASN, compared to part-time or no ASN, on thrombolysis rates and times.

Methods: Data was extracted from the hospital’s stroke thrombolysis database for the period 2004 to 2012. Comparisons were made for those patients seen by the ASN, when FT and PT and those who saw medical staff only. Statistical comparisons were made using Mann-Whitney Rank Sum test.

Results: Almost half (43% n=182) of the 428 thrombolysis cases occurred during business hours, the ASN attended 84% of cases when the role was filled FT and 15% when PT. No difference was seen in median door-to-CT times (25 minutes.) Faster median door-to-needle times were achieved during business hours when the patient was seen by the ASN compared to those who were not (66 mins vs. 83 mins, p=<0.001.) Faster times were seen when the ASN role was FT (68 min) or PT (79 min) compared to vacant (89 mins, p=0.006,) with more patients treated within 60 minutes of arrival (35% FT, 27% PT and 8% vacant, NS). While the ASN only works within business hours, faster door-to-needle times were seen after hours when the ASN role was filled FT and PT compared to vacant (87mins and 100 mins vs. 103 mins, p=0.013;) and treatment was only commenced under 60 minutes when the ASN was employed FT.

Conclusion: The Acute Stroke Nurse role seems to have a positive impact on thrombolysis treatment times and rates, with the best results being achieved during and outside business hours when the ASN is employed FT.

Exercise in the community for people with minimal gait impairment due to MS: an assessor-blind randomized controlled trial

Background:

While there is an increasing body of evidence supporting the efficacy of exercise in people with multiple sclerosis (MS), additional information on the effectiveness of combining aerobic and resistance training, and yoga is required.

Objectives:

This study evaluated the effectiveness of community exercise interventions for people with MS having minimal gait impairment.

Methods:

A multi-centred, block-randomised, assessor-blinded, controlled trial was conducted. Participants were randomised in groups of eight to physiotherapist (PT)-led exercise ( n = 80), yoga ( n = 77), fitness instructor (FI)-led exercise ( n = 86) and they took part in weekly community-based group exercise sessions. Those in the control group were asked not to change of their exercise habits ( n = 71). The primary outcome was the Multiple Sclerosis Impact Scale (MSIS) 29v2 physical component, measured before and after the 10-week intervention. Secondary outcomes were the MSIS 29v2 psychological component, the Modified Fatigue Impact Scale (MFIS) and the 6-Minute Walk Test (6MWT).

Results:

The group x time interaction approached significance for the MSIS-29v2 physical component ( f = 2.48, p = 0.061) and MFIS total ( f = 2.50, p = 0.06), and it was significant for the MFIS physical subscale ( f = 4.23, p = 0.006). All three exercise interventions led to a statistically significant improvement on the MSIS-29 psychological component and both the MFIS total and physical subscales, which were greater than the control ( p < 0.05). Only the PT-led and FI-led interventions significantly improved the MSIS-29 physical and 6MWT to levels greater than the control ( p < 0.05).

Conclusions:

This study provides evidence for the positive effect of exercise on the physical impact of MS and fatigue. The group nature of the classes may have contributed to the positive effects seen on the psychological impact of MS.

Induced hypothermia after out-of-hospital cardiac arrest: one hospital's experience

OBJECTIVE

Induced mild hypothermia has been shown to reduce in-hospital mortality and to improve neurological outcome in patients who remain comatose after out-ofhospital cardiac arrest (OHCA). We conducted a retrospective audit to assess whether induced hypothermia had been successfully incorporated into routine care at our hospital, and whether this improved patient outcomes.

DESIGN AND SETTING

Retrospective audit of patients admitted to a Level III intensive care unit, Melbourne, Victoria, between 2001 and 2007. Patients treated with therapeutic hypothermia (introduced in 2004) were compared with those who did not receive this therapy.

PARTICIPANTS

Patients admitted to the ICU comatose after OHCA with a presumed cardiac cause.

INTERVENTIONS

Induction of mild hypothermia by rapid infusion of cold intravenous fluids.

MAIN OUTCOME MEASURES

Hospital survival and neurological outcome at hospital discharge; time taken for core temperature to reach the target range (33 degrees +/-0.5 degrees C) and time temperature was maintained, determined from patient ICU records.

RESULTS

123 patients were admitted comatose after OHCA with a presumed cardiac cause: 75 were admitted after induced hypothermia was introduced into routine care and received this treatment; and 48 admitted earlier did not receive the treatment. For patients with the initial rhythm of ventricular fibrillation (VF) or unstable ventricular tachycardia (uVT), treatment with induced hypothermia was associated with a higher hospital survival rate (P=0.03; odds ratio [OR], 2.51; 95% CI, 1.06-5.95) and better neurological outcome (P=0.02; OR, 2.85; 95% CI, 1.19-6.86). In 90% of patients treated with induced hypothermia, core temperature reached the target range within 6 hours of hospital presentation; mean duration of in-hospital cooling was 25.5 hours (SD, 2.9 hours).

CONCLUSIONS

We found that induced hypothermia can be incorporated into routine care of patients admitted to an ICU after OHCA. For patients with an initial rhythm of VF or uVT, this seems to have significantly improved hospital survival and neurological outcome. We also found that rapid infusion of cold intravenous fluids was effective for inducing hypothermia.