Comparison of Magnetic Resonance Analysis of Myocardial Scarring With Biomarker Release Following S-T Elevation Myocardial Infarction.

BACKGROUND: Late gadolinium enhancement (LGE) with cardiac magnetic resonance (CMR) is commonly assumed to represent myocardial fibrosis; however, comparative human histological data are limited, and there is no consensus on the most accurate method for LGE quantitation. We evaluated the relationship between CMR assessment of regional fibrosis and infarct size assessment using serial biomarkers after ST elevation acute myocardial infarction (STEMI). METHODS: Ninety-three patients treated for STEMI (59±10 years, 86% male) underwent CMR 6 months after infarction. Infarct size was quantified by CMR-LGE using manual and range of semi-automated thresholds (range: 2-10 standard deviations [SD]) above reference myocardium and the full width-half maximum (FWHM) technique, and compared with the rise in serum biomarkers. The agreement between CMR and biomarker in the identification of large infarcts based on peak troponin (TnI) levels was also analysed. RESULTS: Quantification methods had a strong influence on the infarct size assessment with CMR-LGE. Significant correlations were observed between LGE and biomarkers across all of the signal intensity thresholds. Whilst there was a wide variation with respect to the estimation of total LGE size (from 6.8±7.7 to 32.1±11.3 grams), the variation in the correlation with peak troponin level was much smaller (r-values ranging from 0.670 to 0.876). There was good agreement between CMR-LGE and biomarker assessment of infarct size; the best agreement between CMR-LGE and large infarction using a threshold of 8SD for peak TnI>50ng/mL (Cohen's kappa (κ)=0.722), and a threshold of 4SD for peak TnI >95ng/mL (κ=0.761). CONCLUSIONS: The correlation between CMR-LGE quantification of infarct size and biomarker release following STEMI at a range of semi-automated thresholds was consistently strong, with good agreement between measures across a range of thresholds.

Identifying barriers to the provision of bystander cardiopulmonary resuscitation (CPR) in high-risk regions: A qualitative review of emergency calls.

INTRODUCTION: Understanding regional variation in bystander cardiopulmonary resuscitation (CPR) is important to improving out-of-hospital cardiac arrest (OHCA) survival. In this study we aimed to identify barriers to providing bystander CPR in regions with low rates of bystander CPR and where OHCA was recognised in the emergency call. METHODS: We retrospectively reviewed emergency calls for adults in regions of low bystander CPR in the Australian state of Victoria. Included calls were those where OHCA was identified during the call but no bystander CPR was given. A thematic content analysis was independently conducted by two investigators. RESULTS: Saturation of themes was reached after listening to 139 calls. Calls progressed to the point of compression instructions before EMS arrival in only 26 (18.7%) of cases. Three types of barriers were identified: procedural barriers (time lost due to language barriers and communication issues; telephone problems), CPR knowledge (skill deficits; perceived benefit) and personal factors (physical frailty or disability; patient position; emotional factors). CONCLUSION: A range of factors are associated with barriers to delivering bystander CPR even in the presence of dispatcher instructions - some of which are modifiable. To overcome these barriers in high-risk regions, targeted public education needs to provide information about what occurs in an emergency call, how to recognise an OHCA and to improve CPR knowledge and skills.

Effect of supplemental oxygen exposure on myocardial injury in ST-elevation myocardial infarction.

OBJECTIVE: Supplemental oxygen therapy may increase myocardial injury following ST-elevation myocardial infarction (STEMI). In this study, we aimed to evaluate the effect of the dose and duration of oxygen exposure on myocardial injury after STEMI. METHODS: Descriptive analysis of data from a multicentre, prospective, randomised, controlled trial of 441 patients with STEMI randomised to supplemental oxygen therapy or room air breathing. The primary endpoint was myocardial infarct size as assessed by cardiac biomarkers, troponin (cTnI) and creatine kinase (CK). Oxygen therapy was commenced by paramedics, and continued for up to 12 h postintervention in hospital. Supplemental oxygen exposure was calculated as the area under the dose×time curve for oxygen administration over the first 12 h, and then assessed for its association with cTnI/CK release using multivariable linear regression. RESULTS: The median supplemental oxygen exposure was 1746 L (IQR: 960-2858). After adjustment for potential confounders, every 100 L increase in oxygen exposure in the first 12 h was associated with a 1.4% (95% CI 0.6% to 2.2%, p<0.001) and 1.2% (95% CI 0.7% to 1.8%, p<0.001) increase in the mean peak cTnI and CK, respectively. Excluding patients who developed cardiogenic shock, recurrent myocardial infarction or desaturations (SpO2<94%) during admission, every 100 L increase in oxygen exposure was associated with a 1.2% (95% CI 0.2% to 2.1%, p=0.01) and 1.0% (95% CI 0.3% to 1.7%, p=0.003) increase in the mean peak cTnI and CK, respectively. The median supplemental oxygen exposure of 1746 L would result in a 21% (95% CI 3% to 37%) increase in infarct size according to the cTnI profile. CONCLUSIONS: Supplemental oxygen exposure in the first 12 h after STEMI was associated with a clinically significant increase in cTnI and CK release.

Air Versus Oxygen in ST-Segment-Elevation Myocardial Infarction.

BACKGROUND: Oxygen is commonly administered to patients with ST-elevation-myocardial infarction despite previous studies suggesting a possible increase in myocardial injury as a result of coronary vasoconstriction and heightened oxidative stress. METHODS AND RESULTS: We conducted a multicenter, prospective, randomized, controlled trial comparing oxygen (8 L/min) with no supplemental oxygen in patients with ST-elevation-myocardial infarction diagnosed on paramedic 12-lead ECG. Of 638 patients randomized, 441 patients had confirmed ST-elevation-myocardial infarction and underwent primary end-point analysis. The primary end point was myocardial infarct size as assessed by cardiac enzymes, troponin I, and creatine kinase. Secondary end points included recurrent myocardial infarction, cardiac arrhythmia, and myocardial infarct size assessed by cardiac magnetic resonance imaging at 6 months. Mean peak troponin was similar in the oxygen and no oxygen groups (57.4 versus 48.0 µg/L; ratio, 1.20; 95% confidence interval, 0.92-1.56; P=0.18). There was a significant increase in mean peak creatine kinase in the oxygen group compared with the no oxygen group (1948 versus 1543 U/L; means ratio, 1.27; 95% confidence interval, 1.04-1.52; P=0.01). There was an increase in the rate of recurrent myocardial infarction in the oxygen group compared with the no oxygen group (5.5% versus 0.9%; P=0.006) and an increase in frequency of cardiac arrhythmia (40.4% versus 31.4%; P=0.05). At 6 months, the oxygen group had an increase in myocardial infarct size on cardiac magnetic resonance (n=139; 20.3 versus 13.1 g; P=0.04). CONCLUSION: Supplemental oxygen therapy in patients with ST-elevation-myocardial infarction but without hypoxia may increase early myocardial injury and was associated with larger myocardial infarct size assessed at 6 months. CLINICAL TRIAL REGISTRATION: URL: http://www.clinicaltrials.gov. Unique identifier: NCT01272713.

Effect of public awareness campaigns on calls to ambulance across Australia.

BACKGROUND AND PURPOSE: The National Stroke Foundation of Australia has run 12 public awareness campaigns since 2004. Campaign exposure and funding has varied annually and regionally during this time. The aim of this study was to measure the effect of campaigns on calls to ambulance for stroke across Australia in exposed regions (paid or pro bono advertising). METHODS: All ambulance services in Australia provided monthly ambulance dispatch data between January 2003 and June 2014. We performed multivariable regression to measure the effect of campaign exposure on the volume of stroke-related emergency calls, after controlling for confounders. RESULTS: The final model indicated that 11 of the 12 National Stroke Foundation campaigns were associated with increases in the volume of stroke-related calls (varying between 1% and 9.9%) in regions with exposure to advertising. This increase lasted ≈3 months, with an additional 10.2% relative increase in the volume of the calls in regions with paid advertising. We found no significant additional effect of the campaigns on stroke calls where ambulance services are publicly funded. CONCLUSIONS: The National Stroke Foundation stroke awareness campaigns are associated with increases to calls to ambulance for stroke in regions receiving advertising and promotion. Research is now required to examine whether this increased use in ambulance is for appropriate emergencies.

Evaluation of the Victorian state adult pre-hospital trauma triage criteria.

BACKGROUND: Pre-hospital trauma triage criteria are used to expedite the transport of severely injured patients to major trauma services. The current Victorian adult pre-hospital trauma triage criteria consist of physiological, anatomical and mechanistic elements. The purpose of this study was to evaluate the performance of the current triage criteria and, if necessary propose refined criteria to improve the under and over-triage rates. METHODS: The study was conducted in Melbourne, Victoria, which has a fully integrated State Trauma System. Trauma data was sourced from the pre-hospital Victorian Ambulance Clinical Information System and the Victorian State Trauma Registry. Confirmed major trauma was defined at hospital discharge as one or more of death, ISS>15, ICU ventilation or urgent surgery. Data was matched through probabilistic linkage. The triage criteria were evaluated using multivariate logistic regression and classification tree modelling. Diagnostic statistics, including sensitivity and specificity were calculated to assess triage performance. RESULTS: Over 12-months there were 1166 'confirmed major trauma' patients and 44,166 'non-major trauma' patients. Evaluation showed the current triage criteria needed refinement, and multiple revised pre-hospital trauma triage models were constructed. Based on the best overall combination of diagnostic statistics, a revised model was chosen with a sensitivity of 97.8% (vs. 95.3% in the current model), a specificity of 82.7% (vs. 62.7%) and an accuracy of 83.0% (vs. 63.4%). The over-triage rate was 17.3% (vs. 37.3%) and the under-triage rate was 2.2% (vs. 4.7%). CONCLUSIONS: Evaluation showed that the specificity and sensitivity of the current trauma triage criteria could be improved. The implementation of a revised triage model should identify more confirmed major trauma patients. Likewise, over-triage of non-major trauma patients to major trauma services would be significantly reduced. The refined criteria should also decrease discretionary decision-making by paramedics in the field.

Stroke public awareness campaigns have increased ambulance dispatches for stroke in Melbourne, Australia.

BACKGROUND AND PURPOSE: Launch of the National Stroke Foundation stroke awareness campaigns has occurred annually during Stroke Week (September) since 2004. From 2006, the campaign used FAST (Face, Arm, Speech, Time) with calling an ambulance added in 2007. The aim of this study was to explore the impact of these campaigns on ambulance dispatches for stroke (Medical Priority Dispatch Card 28) in Melbourne, Australia. METHODS: A cross-sectional study examining the monthly proportions of ambulance dispatches for stroke between August 1999 and 2010 was conducted. The proportions of dispatches for stroke were used due to increases in the population and in ambulance dispatches over the study period. These proportions were statistically compared for the month before Stroke Week (August) and the month after Stroke Week (October) for each year and seasonal variation was examined. RESULTS: Between 1999 and 2009, the annual proportion of dispatches for stroke increased from 2.1% (n=4327) to 2.95% (n=9918). When stroke dispatches in August were compared with those in October, a significant increase in October was only detected since the call an ambulance message was added to FAST: 2007 (2.62% to 3.00%, P=0.006), 2008 (2.62% to 3.05%, P=0.003), and 2009 (2.70% to 3.09%, P=0.007). From 2005, the peak season for stroke dispatches shifted from winter to spring. CONCLUSIONS: Ambulance dispatches for stroke significantly increased after the National Stroke Foundation campaigns began, particularly in years receiving greater funding and featuring the FAST symptoms and the message to call an ambulance. Monitoring ambulance use appears to be an effective measure of campaign penetration.

Differentiation of confirmed major trauma patients and potential major trauma patients using pre-hospital trauma triage criteria.

BACKGROUND: There is a paucity of literature comparing trauma patients who meet pre-hospital trauma triage guidelines ('potential major trauma') with trauma patients who are identified as 'confirmed major trauma patients' at hospital discharge. This type of epidemiological surveillance is critical to continuous performance monitoring of mature trauma care systems. The current study aimed to determine if the current trauma triage criteria resulted in under/over-triage and whether the triage criteria were being adhered to. METHODS: For a 12-month time period there were 45,332 adult (≥16 years of age) trauma patients transported by ambulance to hospitals in metropolitan Melbourne. This retrospective study analysed data from 1166 patients identified at hospital discharge as 'confirmed major trauma patients' and 16,479 patients captured by the current pre-hospital trauma triage criteria, who did not go on to meet the definition of confirmed major trauma. These patients comprise the 'potential major trauma' group. Non-major trauma patients (N=27,687) were excluded from the study. Pre-hospital data was sourced from the Victorian Ambulance Clinical Information System (VACIS) and hospital data was sourced from the Victorian State Trauma Registry (VSTR). Statistical analyses compared the characteristics of confirmed major trauma and potential major trauma patients according to the current trauma triage criteria. RESULTS: The leading causes of confirmed major trauma and potential major trauma were motor vehicle collisions (30.1% vs. 19.2%) and falls (30.0% vs. 48.7%). More than 80% of confirmed major trauma and 24.4% of potential major trauma patients were directly transported to a major trauma service. Overall, similar numbers of confirmed major trauma patients and potential major trauma patients had one or more aberrant vital signs (67.0% vs. 66.4%). Specific injuries meeting triage criteria were sustained by 69.2% of confirmed major trauma patients and 51.4% of potential major trauma patients, while 11.7% of confirmed major trauma patients and 4.6% of potential major trauma patients met the combined mechanism of injury criteria. CONCLUSIONS: While the sensitivity of the current pre-hospital trauma triage criteria is high, if paramedics strictly followed the criteria there would be significant over-triage. Triage models using different mechanistic and physiologic criteria should be evaluated.

Paramedic diagnosis of stroke: examining long-term use of the Melbourne Ambulance Stroke Screen (MASS) in the field.

BACKGROUND AND PURPOSE: Recent evidence suggests the Cincinnati Prehospital Stroke Scale is ineffectively used and lacks sensitivity and specificity. Melbourne (Australia) paramedics have been using the Melbourne Ambulance Stroke Screen (MASS) since 2005. The aim of this study was to review the real-world use of MASS 3 years after city wide implementation. METHODS: Two groups of consecutively admitted patients to an Australian hospital between January and May 2008 were used: (1) patients for whom paramedics performed MASS; and (2) patients with a discharge diagnosis of stroke or transient ischemic attack. Use of MASS was examined for all transports and for patients diagnosed with stroke or transient ischemic attack. The sensitivity and specificity of paramedic diagnosis, MASS, and Cincinnati Prehospital Stroke Scale were calculated. Paramedic diagnosis of stroke among patients with stroke was statistically compared with those obtained immediately post-MASS implementation in 2002. RESULTS: For the study period, MASS was performed for 850 (16%) of 5286 emergency transports, including 199 of 207 (96%) patients with confirmed stroke and transient ischemic attack. In patients in whom MASS was performed (n=850), the sensitivity of paramedic diagnosis of stroke (93%, 95% CI: 88% to 96%) was higher than the MASS (83%, 95% CI: 77% to 88%, P=0.003) and equivalent to Cincinnati Prehospital Stroke Scale (88%, 95% CI: 83% to 92%, P=0.120), whereas the specificity of the paramedic diagnosis of stroke (87%, 95% CI: 84% to 89%) was equivalent to MASS (86%, 95% CI: 83% to 88%, P=0.687) and higher than Cincinnati Prehospital Stroke Scale (79%, 95% CI: 75% to 82%, P<0.001). The initial improvement in stroke paramedic diagnosis seen in 2002 (94%, 95% CI: 86% to 98%) was sustained in 2008 (89%, 95% CI: 84% to 94%, P=0.19). CONCLUSIONS: In our experience, paramedics have successfully incorporated MASS into the assessment of neurologically compromised patients. The initial improvement to the paramedics' diagnosis of stroke with MASS was sustained 3 years after city wide implementation.

An intervention to encourage ambulance paramedics to bring patients' own medications to the ED: impact on medications brought in and prescribing errors.

OBJECTIVE: To undertake and evaluate a multifaceted intervention to encourage paramedics to bring patients' own medications (POM) to the ED. METHOD: Adult patients were enrolled in each of the pre-intervention (March 2006) and post-intervention (December 2006) periods if they were brought to ED by ambulance, taking four or more medications, admitted to hospital and were not referred to a pharmacist prior to the admission medication chart being written. ED pharmacists determined patients' regular medication and details of medications brought in by ambulance. Medication charts were assessed for discrepancies related to medications taken prior to presentation. These were recorded as errors if a change was made to the medication chart after discussion with the prescriber. The intervention, conducted in October and November 2006, involved meetings with Metropolitan Ambulance Service* team managers and dissemination of promotional material. Paramedics of the Metropolitan Ambulance Service were participants for the intervention. Main outcome measures were: percentage of regular medications incorrectly prescribed; and percentage of POM brought to ED by paramedics. RESULTS: One hundred patients were enrolled in each of the pre- and post-intervention periods. The percentage of regular medications incorrectly prescribed significantly decreased from 18.9% (151/800, 95% CI 16-22%) to 8.8% (73/834, 95% CI 7-11%) in the pre- and post-intervention periods, respectively (P<0.001). Pre-intervention, paramedics brought some or all POM to ED in 67.0% (67/100, 95% CI 57-76%) of cases compared with 87.0% (87/100, 95% CI 78-93%) of cases, post-intervention. CONCLUSION: The multifaceted intervention encouraging paramedics to bring POM to ED was effective. POM were brought into ED more frequently and prescribing errors reduced.

Prehospital 12-lead ECG to triage ST-elevation myocardial infarction and emergency department activation of the infarct team significantly improves door-to-balloon times: ambulance Victoria and MonashHEART Acute Myocardial Infarction (MonAMI) 12-lead ECG project.

BACKGROUND: American College of Cardiology/American Heart Association guidelines recommend >75% of patients with an ST-elevation myocardial infarction receive primary percutaneous coronary interventions (PPCI) within 90 minutes. Despite these recommendations, this goal has been difficult to achieve. METHODS AND RESULTS: We conducted a prospective interventional study involving 349 patients undergoing PPCI at a single tertiary referral institution to determine the impact of prehospital 12-lead ECG triage and emergency department activation of the infarct team on door-to-balloon time (D2BT). The median D2BT of all patients (n=107) who underwent PPCI after field ECG and emergency department activation of the infarct team (MonashHEART Acute Myocardial Infarction [MonAMI] group) was 56 minutes (interquartile range, 36.5 to 70) compared with the median time of a contemporary group (n=122) undergoing PPCI during the same period but not receiving field triage (non-MonAMI group) of 98 minutes (73 to 126.45). The median D2BT time of 120 consecutive patients who underwent PPCI before initiation of the project (pre-MonAMI group) was 101.5 minutes (72.5 to 134; P<0.001). The proportion of patients who achieved a D2BT of < or = 90 minutes increased from 39% in the pre-MonAMI group and 45% in the non-MonAMI group to 93% in the MonAMI group (P<0.001). CONCLUSIONS: The performance of prehospital 12-lead ECG triage and emergency department activation of the infarct team significantly improves D2BT and results in a greater proportion of patients achieving guideline recommendations.

Randomized controlled trial comparing the effectiveness and safety of intranasal and intramuscular naloxone for the treatment of suspected heroin overdose.

AIMS: Traditionally, the opiate antagonist naloxone has been administered parenterally; however, intranasal (i.n.) administration has the potential to reduce the risk of needlestick injury. This is important when working with populations known to have a high prevalence of blood-borne viruses. Preliminary research suggests that i.n. administration might be effective, but suboptimal naloxone solutions were used. This study compared the effectiveness of concentrated (2 mg/ml) i.n. naloxone to intramuscular (i.m.) naloxone for suspected opiate overdose. METHODS: This randomized controlled trial included patients treated for suspected opiate overdose in the pre-hospital setting. Patients received 2 mg of either i.n. or i.m. naloxone. The primary outcome was the proportion of patients who responded within 10 minutes of naloxone treatment. Secondary outcomes included time to adequate response and requirement for supplementary naloxone. Data were analysed using multivariate statistical techniques. RESULTS: A total of 172 patients were enrolled into the study. Median age was 29 years and 74% were male. Rates of response within 10 minutes were similar: i.n. naloxone (60/83, 72.3%) compared with i.m. naloxone (69/89, 77.5%) [difference: -5.2%, 95% confidence interval (CI) -18.2 to 7.7]. No difference was observed in mean response time (i.n.: 8.0, i.m.: 7.9 minutes; difference 0.1, 95% CI -1.3 to 1.5). Supplementary naloxone was administered to fewer patients who received i.m. naloxone (i.n.: 18.1%; i.m.: 4.5%) (difference: 13.6%, 95% CI 4.2-22.9). CONCLUSIONS: Concentrated intranasal naloxone reversed heroin overdose successfully in 82% of patients. Time to adequate response was the same for both routes, suggesting that the i.n. route of administration is of similar effectiveness to the i.m. route as a first-line treatment for heroin overdose.

Bringing patients' own medications into an emergency department by ambulance: effect on prescribing accuracy when these patients are admitted to hospital.

OBJECTIVE: To determine whether the availability of patients' own medications (POM) in emergency departments (EDs) results in decreased prescribing errors of patients' usual medications on admission. DESIGN, PARTICIPANTS AND SETTING: Observational study of patients presenting by ambulance to the ED of Austin Hospital, a Melbourne metropolitan teaching hospital, between 13 and 31 March 2006. Patients were enrolled if they were brought to the ED by ambulance, aged 18 years or older, taking four or more regular medications, admitted to hospital, and not referred to a pharmacist before the admission medication chart was written. ED pharmacists determined patients' regular medications and details of medications brought in by ambulance. Admission medication charts were assessed and discrepancies were recorded as prescribing errors if a change was made after a pharmacist discussed the discrepancy with the prescriber. MAIN OUTCOME MEASURES: Percentage of medications correctly prescribed when POM were brought in to the ED compared with when they were not; the nature and frequency of prescribing errors on admission. RESULTS: 100 patients were enrolled; they were taking 4-17 regular medications (mean, 8.0; SD, 3.7). Among the 428 POM that were brought to the ED, 56 errors occurred (13.1%); and among the 372 regular medications taken by patients for whom POM were not brought in, 95 errors occurred (25.5%) (difference in percentages, 12.4%; 95% CI, 6.7%-18.0%; P<0.001). The most prevalent prescribing errors were omissions (40.4%), and most errors (72.8%) were classified as of "moderate" clinical significance. CONCLUSIONS: When POM were brought to the ED by paramedics, significantly fewer errors occurred on admission medication charts. An intervention program to encourage paramedics to bring POM to the ED is indicated.

An interventional study to improve paramedic diagnosis of stroke.

OBJECTIVE: The aim of the Faster Access to Stroke Therapy (FAST) study was to determine the effect of educational intervention and the use of a prehospital stroke tool on the paramedic diagnosis of stroke. METHODS: Paramedics in emergency medical service units servicing a university teaching hospital were divided into two groups: FAST study paramedics (n = 18) and non-FAST study paramedics (n = 43). The FAST study paramedics received stroke education and instruction in the use of a prehospital stroke assessment tool [Melbourne Ambulance Stroke Screen (MASS)] to assist in stroke diagnosis. Based on final hospital diagnosis, the sensitivities of paramedic stroke diagnosis in the two groups were compared for a 12-month period before and after the intervention. RESULTS: The sensitivity for the FAST study paramedics in identifying stroke improved from 78% (95% confidence interval [CI]: 63% to 88%) to 94% (95% CI: 86% to 98%) (p = 0.006) after receiving the stroke education session and with use of the MASS tool. There was no change in stroke diagnosis for the non-study paramedics 78% (95% CI: 71% to 84%) to 80% (95% CI: 72% to 87%) (p = 0.695). Pre-notification of impending arrival to the emergency department was associated with higher-priority triage in the emergency department, and subsequent shorter times for door to medical review (15 min vs. 31 min, p < 0.001) and door to computed tomography (CT) scanning (94 min vs. 144 min, p < 0.001). CONCLUSIONS: Targeted stroke education and the use of a simple clinical tool can significantly improve the diagnostic sensitivity of stroke by paramedics in the prehospital setting. Accurate diagnosis combined with pre-notification of the pending arrival of stroke patients will allow for the focused and timely application of resources for the management of acute stroke.

Paramedic identification of stroke: community validation of the melbourne ambulance stroke screen.

BACKGROUND: Paramedics require an effective prehospital tool to eliminate stroke mimics and to assist in the identification of suitable candidates for thrombolytic therapy. The Faster Access to Stroke Therapies study combined two validated stroke assessment tools (the Los Angeles Prehospital Stroke Screen, LAPSS, and the Cincinnati Prehospital Stroke Scale, CPSS) to form the Melbourne Ambulance Stroke Screen (MASS), and performed an in-field validation by Australian paramedics. METHODS: Over a 12-month period, 18 paramedics participated in the Faster Access to Stroke Therapies study and prospectively collected data contained in the MASS on all stroke dispatches, and for other patients with a focal neurological deficit. Sensitivity and specificity analysis of the LAPSS, CPSS and MASS was calculated and equivalence analysis performed. RESULTS: Paramedics completed 100 MASS assessments for 73 (73%) stroke/transient ischemic attack patients and 27 (27%) stroke mimics. The sensitivity of the MASS (90%, 95% CI: 81-96%) showed statistical equivalence to the sensitivity of the CPSS (95%, p = 0.45) and superiority to the LAPSS (78%, p = 0.008). The specificity of the MASS (74%, 95% CI: 53-88%) was equivalent to that of the LAPSS (85%, p = 0.25) and superior to the CPSS (54%, p = 0.007). All patients misidentified by the MASS (7 strokes, 7 mimics) were ineligible for thrombolytic therapy. CONCLUSION: The MASS is simple to use, with accurate prehospital identification of stroke. It distinguishes stroke mimics, with good recognition of suitable patients for thrombolytic therapy.