Identifying Key Words in 9-1-1 Calls for Stroke: A Mixed Methods Approach

Area of Science:

• Emergency medical services
• Neurology
• Linguistics

Background:

• Timely stroke identification during 9-1-1 calls is crucial for effective prehospital care.
• Emergency Medical Dispatchers (EMDs) recognize stroke in less than half of calls, potentially due to callers' language.
• Callers often do not use classical stroke descriptors like focal neurologic deficits.

Purpose of the Study:

• To identify words and phrases commonly used by 9-1-1 callers to describe acute stroke victims.
• To investigate the hypothesis that callers do not typically use classical stroke descriptors.
• To explore the utility of a mixed-methods approach in analyzing caller language for stroke identification.

Main Methods:

• A retrospective study of 110 audio recordings of 9-1-1 calls for adult stroke patients.
• Utilized content analysis (qualitative) and computational linguistics (quantitative) to identify key caller language.
• Assessed caller emotional state using the Emotional Content and Cooperation Score.

Main Results:

• EMDs recognized stroke in 48% of calls; 95% of callers were calm.
• The word "stroke" was used in only 38% of calls, though in 77% of calls where stroke was recognized.
• Vague or distractor words were used in 55% of calls; focal neurologic symptoms in 39%.

Conclusions:

• Most 9-1-1 callers use non-specific or distractor language, rarely using classic stroke descriptions.
• Both qualitative and quantitative methods identified similar key phrases linked to accurate EMD stroke recognition.
• Tools incorporating common caller language could enhance EMD stroke recognition and improve patient outcomes.