The accuracy of the FAST stroke assessment in identifying stroke at initial ambulance call into a South African private emergency call centre

BACKGROUND: Stroke is a potentially life-threatening, time-dependent event, and one of the leading causes of mortality and lasting morbidity in South Africa (SA). It is of vital importance that Emergency Medical Services (EMS) call-takers accurately recognise stroke symptoms and prioritise time as well as adequate care. EMS call-takers are the first link in stroke care and improving call-taker recognition of stroke signs and symptoms can drastically improve patient outcome. The Newcastle Face Arm Speech Time (FAST) test is a mnemonic aimed at improving diagnostic accuracy of stroke. OBJECTIVES: To assess the use of the FAST test at a call-taker level to raise early suspicion of stroke and appropriately allocate resources to increase awareness of time and decrease delays on scene. METHODS: A retrospective diagnostic study to determine the accuracy of the FAST mnemonic at identifying stroke when applied at EMS call-taker level. The outcome of the FAST assessment was compared with EMS stroke diagnosis for cases of a private SA EMS over a three-month period (N=146). RESULTS: Using FAST, call-takers were able to identify stroke with a sensitivity of 87.5% and a specificity of 17.4% (positive predictive value 34%, negative predictive value 74%). This yielded an overall accuracy of 40.41%. CONCLUSION: FAST is a useful screening tool for identifying stroke at call-taker level. FAST has acceptable sensitivity when used as a screening tool; however, specificity and diagnostic effectiveness are lacking. Further studies should be considered to determine call-taker as well as general public knowledge of stroke risk factors and presentation. CONTRIBUTIONS OF THE STUDY: Stroke is one of the leading causes of death and lasting morbidity in South Africa (SA) and is increasing in incidence. Early recognition of stroke at initial emergency call may expedite treatment, thus improving outcomes. This study demonstrates that the application of the FAST assessment at emergency contact centre level in SA, might be useful at identifying stroke early. Future research should investigate barriers to its use.