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

Abstract

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.

Objective. 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