Purpose: To observe if there is a mismatch between AED installation and out-of-hospital cardiac arrest (OHCA) occurrence by visualizing those spatial distributions.
Materials and Methods: Places of AED installation and OHCA attended by the EMS were surveyed in the City of Kobe, Osaka, and Nagoya over the 4-year period (2012 to 2015). The density functions of those places (DAED and DOHCA, respectively) were estimated using kernel distribution estimation, and the relative density (DAED / DOHCA) were superimposed on the city maps.
Results: Both DAED and DOHCA were relatively high over busy shopping/business districts, seemingly suggesting an appropriate distribution of AEDs. However, mapping of relative density revealed a significant mismatch between DAED and DOHCA with an area-to-area difference of more than ten times in the ratio of DAED / DOHCA. The issue seemed to represent a critical problem especially in southern downtown of the City of Osaka that has frequent cases of OHCA.
Conclusion: Using the spatial distribution analysis, we visualized the area where there is a mismatch between DAED and DOHCA distributions. This would serve as a useful analytical tool to optimize AED installation in city areas.

1 - A Mismatch of Spatial Distribution between AED Installation and Out-of-hospital Cardiac Arrest.