Paramedic Diagnosis of Stroke Examining Long-Term Use of the Melbourne Ambulance Stroke Screen (MASS) in the Field Janet E. Bray, PhD(C); Kelly Coughlan, BS; Bill Barger, ADHS; Chris Bladin, MD 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 citywide 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). Conclusion—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 citywide implementation. (Stroke. 2010;41:1363-1366.) Key Words: ambulance  diagnosis  emergency services  stroke E mergency medical services (EMS) are an integral part of the acute stroke team. 1 They are fundamental in maximizing the delivery of thrombolytic therapy to pa- tients with stroke by correctly identifying stroke in the field, transporting patients with suspected stroke to acute stroke centers, and activation of Code Stroke Teams through prehospital notification. 2,3 A variety of prehospital stroke screens have been devel- oped to assist EMS to identify patients with stroke in the field (Table 1). 4–7 Our previous work confirmed the value in using these screens, showing an immediate improvement in EMS diagnosis of stroke from a baseline of 78% to 94% after education and with use of the Melbourne Ambulance Stroke Screen (MASS). 8 However, recent investigations of a similar screen, the Cincinnati Prehospital Stroke Scale (CPSS), suggest poor use by paramedics and low sensitivity and specificity. 9,10 Additionally, no long-term evaluations of the use of prehospital screens have been conducted. The aim of this study was to examine the use of MASS in the field 3 years after citywide education and implementation, specifically determining the use of MASS by paramedics and to calculate and compare the sensitivity and specificity of MASS, CPSS, and paramedic diagnosis of stroke to our previous findings. Subjects and Methods This study was a cross-sectional design of consecutive patients transported by EMS to an Australian hospital between January and May 2008. Methods are summarized in the Figure. Institutional ethical approval was received before the start of data collection. Received December 3, 2009; final revision received February 8, 2010; accepted February 27, 2010. From Box Hill Hospital and Deakin University (J.E.B.), Victoria, Australia; Box Hill Hospital (K.C.), Victoria, Australia; Ambulance Victoria (B.B.), Victoria, Australia; and Box Hill Hospital and Monash University (C.B.), Victoria, Australia. Correspondence to Chris Bladin, MD, Box Hill Hospital, Department of Neurosciences, 5 Arnold Street, Box Hill, Victoria, 3128, Australia. E-mail chris.bladin@easternhealth.org.au © 2010 American Heart Association, Inc. Stroke is available at http://stroke.ahajournals.org DOI: 10.1161/STROKEAHA.109.571836 1363 by guest on October 28, 2016 http://stroke.ahajournals.org/ Downloaded from by guest on October 28, 2016 http://stroke.ahajournals.org/ Downloaded from by guest on October 28, 2016 http://stroke.ahajournals.org/ Downloaded from by guest on October 28, 2016 http://stroke.ahajournals.org/ Downloaded from by guest on October 28, 2016 http://stroke.ahajournals.org/ Downloaded from by guest on October 28, 2016 http://stroke.ahajournals.org/ Downloaded from