Variability of automated external defibrillator (AED) signage across six continents: a descriptive cross-sectional study.

BACKGROUND

Out-of-hospital cardiac arrests are associated with high mortality. Despite lay rescuer automated external defibrillator (AEDs) use being crucial for improving outcomes, public utilization of AEDs remains low. Signage characteristics directing lay rescuers to AEDs in public areas vary. We describe AED signage variability across six continents, focusing on shape, color, text, and symbols.

METHODS

A convenience sample of 120 publicly available online AED signage, collected between December 2024 and May 2025, was analyzed. Six continents were included: Europe (38.3%), North America (23.3%), Africa (14.2%), Australia (12.5%), Asia (7.5%), and South America (4.2%). Separately, 90 crowd-sourced images of airport AED signage were collected from 71 airports across six continents between January and November 2025: Europe (37.8%), North America (36.7%), Africa (1.1%), Australia (6.7%), Asia (15.6%), and South America (5.6%). We reported frequencies and proportions of signage characteristics for the samples and stratified by continent.

RESULTS

The distribution of signage characteristics in the publicly available signage varied across six continents (p < 0.05). In the airport sample, the distribution of sign shape; cross symbol color; and the presence of heart, lightning bolt, and arrow symbols did not differ across continents. However, background color, text color, presence of the cross symbol, and colors of the heart and lightning bolt symbols differed across continents (p < 0.05). Over 90% of all signs analyzed contained a heart and lightning bolt symbol.

CONCLUSIONS

There appears to be significant variation in public AED signage globally. Further research is needed to determine if specific signage characteristics improve AED recognition and utilization.