Platform Presentation The Joint Annual Meeting of the Stroke Society of Australasia (SSA) and Smartstrokes 2023

Utility of the Call-taker FAST Screen for Patients Receiving Reperfusion Therapy (#71)

Ahmed Haliem 1 2 , Candice Menezes 1 2 , Leonid Churilov 2 3 4 , Dominic Italiano 2 , Skye Coote 2 3 , Damien Easton 2 3 , Francesca Langenberg 2 3 , Gargan Sharma 1 2 , Prodipta Guha 1 , Ziad Nehme 5 6 , Emily Nehme 5 , Belinda Delardes 5 , James Beharry 3 , Geoffrey Donnan 2 3 , Stephen Davis 2 3 , Bruce Campbell 2 3 , Lauren Christie 7 , Henry Zhao 2 3
  1. Melbourne Brain Centre at Royal Melbourne Hospital, Melbourne, VICTORIA, Australia
  2. Medicine, University of Melbourne , Melbourne, Victoria , Australia
  3. Neurology , Royal Melbourne Hospital, Melbourne, Victoria , Australia
  4. Medicine , Austin Health , Melbourne , Victoria, Australia
  5. Research and Evaluation, Ambulance Victoria, Melbourne, Victoria , Australia
  6. Paramedicine, Monash University, Melbourne, Victoria , Australia
  7. Allied Research Unit , St Vincent's Health Network, Sydney, New South Wales, Australia

Background: Emergency 000 call-taker algorithms screen for suspected stroke that requires a priority lights and sirens ambulance dispatch. One component is an orally directed face/arm/speech test (FAST) that is weighted to create an ordinal scale ranging from “no test evidence” (all domains normal) to “clear test evidence” (severe abnormality in ≥1 domain). No literature exists to determine the utility of this test against need for time-critical reperfusion therapy.

Aims: We aimed to examine the utility of the 000 call-taker FAST to patients receiving reperfusion therapy (thrombolysis and/or thrombectomy) in consecutive Melbourne Mobile Stroke Unit (MSU) dispatches.

Methods: We linked clinical information from consecutive Melbourne MSU dispatches from 2017-2022 to call-taker information from Ambulance Victoria to determine 000 FAST accuracy against reperfusion therapy need. Additionally, we performed in-depth content analysis on 49 selected 000 call-taker recordings to understand real-world scoring.

Results: We linked 3701 cases with recorded FAST results, of which 304 (8%) received reperfusion therapy. There was a clear increase in the proportion of patients receiving any reperfusion therapy with higher weights for thrombolysis (no evidence 1.5%-> clear evidence 7.6%, p<0.001) and thrombectomy (no evidence 0.6%-> clear evidence 3.7%, p<0.001). Content analysis of call-taker recordings showed that abnormality of all FAST domains was highly associated with need for thrombectomy compared to all other patients (100% vs 24%, p<0.05).

Conclusion: Lack of abnormalities on the 000 call-taker FAST predicted a low need for reperfusion therapies, but treatment rates were still relatively poor with the highest weighting of the FAST. Severe abnormalities in all FAST domains seemed to carry additional diagnostic utility, being found in all thrombectomy cases but only a minority of other cases. As such, there exists the potential to re-weight the test to address low specificity and improve usefulness for ambulance services and MSUs.