Which stroke symptoms prompt a 911 call? A population-based study.

INTRODUCTION: Many studies show that a major barrier to short-term treatment of stroke is patient or bystander delay in responding to stroke symptoms. Most studies have found that less than half of stroke/transient ischemic attack (TIA) events result in a 911 call. We sought to determine which symptoms prompt the public to call 911.

METHODS: A population of 1.3 million within a 5-county region was screened for TIA and all strokes in 1999 using all local hospital International Classification of Diseases, Ninth Edition, codes for stroke (430-436) during 1999. Documented stroke symptoms were abstracted from the medical record. Symptoms were grouped as weakness, numbness, speech/language, confusion/decreased level of consciousness, headache, visual changes, and dizziness/vertigo/coordination. Cases included in this analysis had their strokes at home or work and presented to an emergency department. Logistic regression assessed which symptoms predicted a 911 call, adjusting for age, race, sex, prior stroke, baseline disability, overall stroke severity, home vs work, and stroke subtype.

RESULTS: Two thousand nine hundred seventy-five stroke/TIA patients met inclusion criteria, of whom 40% used emergency medical services. After adjustment, symptoms that increased odds of a 911 call were weakness, confusion/decreased level of consciousness, speech/language, and dizziness/coordination/vertigo. Numbness was less likely to result in a 911 call as were visual changes. The presence of headache was not associated with the decision to call 911.

DISCUSSION: The public appears to respond differently based on the type of stroke symptom, independent of overall severity. Public awareness messages regarding stroke warning signs should be designed with this in mind.