Accuracy of stroke identification by paramedics in a metropolitan prehospital setting: a cohort study


stroke scales

How to Cite

Williams TA, Blacker D, Arendts G, Patrick E, Brink D, Finn J. Accuracy of stroke identification by paramedics in a metropolitan prehospital setting: a cohort study. Australasian Journal of Paramedicine [Internet]. 2017Apr.30 [cited 2023May28];14(2). Available from:



Acute stroke is a medical emergency. Identifying patients suffering a stroke is crucial if paramedics are to maximize delivery of appropriate management. One suggested stroke recognition tool is ‘FAST’ (Face, Arms, Speech, Time) but the accuracy of identifying stroke is unknown. We aimed to (1) examine how paramedics identify patients with stroke; (2) compare paramedic identification of stroke with the Emergency Department (ED) discharge diagnosis of stroke.


A retrospective cohort study was conducted in the Perth metropolitan area in Western Australia between July 2012 and June 2014 using linked data from ambulance and ED databases. Patients aged 45+ years, transported to ED by road ambulance and assigned the ambulance problem code or ED discharge diagnosis of stroke were selected. Positive predictive value (PPV), negative predictive value (NPV), specificity and sensitivity were calculated. Text fields were examined for documentation that patients met FAST criteria.


There were 2,217 patients were identified as stroke by paramedics. Of 1834 patients diagnosed as stroke in ED, 876 patients were not identified as stroke by paramedics. Sensitivity for identification of stroke was 958/1834 (52.2%).  Of 2,096 patients who were identified as stroke by paramedics and had an ED record, 958 patients were identified as stroke by paramedics and in ED. PPV was 958/2096 (45.7%), NPV 99.5% and specificity 99.4%. Paramedics recorded 2 or 3 stroke signs and symptoms in 1,137 (51%) patients.


A systematic approach is needed to better identify patients with stroke in the prehospital setting.


Government of Western Australia Department of Health. Model of Stroke Care 2012. Perth: Health Networks Branch, Department of Health, Western Australia. 2012.

National Stroke Foundation. Clinical Guidelines for Stroke Management. Melbourne: National Stroke Foundation; 2010.

Sheppard JP, Mellor RM, Greenfield S, et al. The association between prehospital care and in-hospital treatment decisions in acute stroke: a cohort study. Emerg Med J 2015;32:93–9.

Patel MD, Rose KM, O'Brien EC, Rosamond WD. Prehospital notification by emergency medical services reduces delays in stroke evaluation: findings from the North Carolina stroke care collaborative. Stroke 2011;42:2263–8.

Iosif C, Papathanasiou M, Staboulis E, Gouliamos A. Social factors influencing hospital arrival time in acute ischemic stroke patients. Neuroradiology 2012;54:361–7.

Silvestrelli G, Parnetti L, Paciaroni M, et al. Early admission to stroke unit influences clinical outcome. Eur J Neurol 2006;13:250–5.

IST-3 collaborative group, Sandercock P, Wardlaw J, et al. The benefits and harms of intravenous thrombolysis with recombinant tissue plasminogen activator within 6 h of acute ischaemic stroke (the third international stroke trial [IST-3]): a randomised controlled trial. Lancet 2012;379:2352–63.

Ebinger M, Winter B, Wendt M, et al. Effect of the use of ambulance-based thrombolysis on time to thrombolysis in acute ischemic stroke: a randomized clinical trial. Jama 2014;311:1622–31.

Lees KR, Bluhmki E, von Kummer R, et al. Time to treatment with intravenous alteplase and outcome in stroke: an updated pooled analysis of ECASS, ATLANTIS, NINDS, and EPITHET trials. Lancet 2010;375:1695–703.

Kothari R, Jauch E, Broderick J, et al. Acute stroke: delays to presentation and emergency department evaluation. Ann Emerg Med 1999;33:3–8.

Lacy CR, Suh DC, Bueno M, Kostis JB. Delay in presentation and evaluation for acute stroke: Stroke Time Registry for Outcomes Knowledge and Epidemiology (S.T.R.O.K.E.). Stroke 2001;32:63–9.

National Stroke Foundation. National Stroke Audit – Acute Services Clinical Audit Report, Clinical Executive Summary 2013. Melbourne, Australia.

Hankey GJ, Blacker DJ. Is it a stroke? BMJ 2015;350:h56.

Turc G, Maier B, Naggara O, et al. Clinical scales do not reliably identify acute ischemic stroke patients with large-artery occlusion. Stroke 2016;47:1466–72.

Kothari RU, Pancioli A, Liu T, Brott T, Broderick J. Cincinnati Prehospital Stroke Scale: reproducibility and validity. Ann Emerg Med 1999;33:373–8.

Chenkin J, Gladstone DJ, Verbeek PR, et al. Predictive value of the Ontario prehospital stroke screening tool for the identification of patients with acute stroke. Prehosp Emerg Care 2009;13:153–9.

Bray JE, Martin J, Cooper G, Barger B, Bernard S, Bladin C. An interventional study to improve paramedic diagnosis of stroke. Prehosp Emerg Care 2005;9:297–302.

de la Ossa NP, Carrera D, Gorchs M, et al. Design and validation of a prehospital stroke scale to predict large arterial occlusion: The Rapid Arterial oCclusion Evaluation Scale. Stroke 2014;45:87–91.

St John Ambulance Western Australia. Clinical practice guidelines for ambulance care in Western Australia Version 24. Belmont: St John Ambulance-Western Australia 2013.

Bray JE, Coughlan K, Barger B, Bladin C. Paramedic diagnosis of stroke: examining long-term use of the Melbourne Ambulance Stroke Screen (MASS) in the field. Stroke 2010;41:1363–6.

Jaro MA. Probabilistic linkage of large public health data files. Stat Med 1995;14:491–8.

Australasian College for Emergency Medicine. The Australasian Triage Scale. Emerg Med (Fremantle) 2002;14:335–6.

Ambulance Victoria (2012). Clinical Practice Guidelines. Available at: [Accessed October 2012].

Association of Amulance Chief Executives, Joint Royal Colleges Ambulance Liaison Committee, The University of Warwick. UK Ambulance Service Clinical Practice Guidelines 2013. Bridgwater, UK: Class Professional Publishing Ltd; 2013.

Koster RW. Modern BLS, dispatch and AED concepts. Best Pract Res Clin Anaesthesiol 2013;27:327–34.

Kidwell CS, Starkman S, Eckstein M, Weems K, Saver JL. Identifying stroke in the field. Prospective validation of the Los Angeles prehospital stroke screen (LAPSS). Stroke 2000;31:71–6.

Department of Health Western Australia (2007). Information Management and Reporting. Emergency Department Data Collection Data Dictionary Version 1.0. Available at: [Accessed 2 October 2010].

Williams TA, Finn J, Celenza A, Teng T-H, Jacobs IG. Paramedic Identification of Acute Pulmonary Edema in a Metropolitan Ambulance Service. Prehosp Emerg Care 2013;17:339–47.

Commonwealth of Australia. The International Statistical Classification of Diseases and Realted Health Problems, Tenth Revision, Australian Modification (ICD-10-AM) 5th Ed. Sydney, NSW: National Centre for Classification in Health; 2006.

Australian Institute of Health and Welfare. Stroke and its management in Australia: an update. Cardiovascular disease series no. 37. Cat. no. CVD 61. Canberra: AIHW, 2013.

Fothergill RT, Williams J, Edwards MJ, Russell IT, Gompertz P. Does use of the recognition of stroke in the emergency room stroke assessment tool enhance stroke recognition by ambulance clinicians? Stroke 2013;44:3007–12.

Brandler ES, Sharma M, McCullough F, et al. Prehospital Stroke identification: factors associated with diagnostic accuracy. J Stroke Cerebrovasc Dis 2015;24:2161–6.

Frendl DM, Strauss DG, Underhill BK, Goldstein LB. Lack of impact of paramedic training and use of the cincinnati prehospital stroke scale on stroke patient identification and on-scene time. Stroke 2009;40:754–6.

Ramanujam P, Guluma KZ, Castillo EM, et al. Accuracy of stroke recognition by emergency medical dispatchers and paramedics--San Diego experience. Prehosp Emerg Care 2008;12:307–13.

Fernandes PM, Whiteley WN, Hart SR, Al-Shahi Salman R. Strokes: mimics and chameleons. Pract Neurol 2013;13:21–8.

Merino JG, Luby M, Benson RT, et al. Predictors of acute stroke mimics in 8187 patients referred to a stroke service. J Stroke Cerebrovasc Dis 2013;22:e397–403.

Bray JE, Martin J, Cooper G, Barger B, Bernard S, Bladin C. Paramedic identification of stroke: community validation of the Melbourne Ambulance Stroke Screen. Cerebrovasc Dis 2005;20:28–33.

Bladin C. Stroke thrombolysis: per ardua, ad astra. Intern Med J 2014;44:111–3.

Williams T, Finn J, Fatovich D, Perkins G, Summers Q, Jacobs I. Paramedic differentiation of asthma and COPD in the prehospital setting is difficult. Prehosp Emerg Care 2015;19:535–43.