BACKGROUND  AND PURPOSE OF THE STUDY:
International resuscitation guidelines unanimously recommend formation of national registries of public access Automated External Defibrillators (AEDs). The benefits of such recommendations are two-fold: to aid both in optimising a bystander response in out-of-hospital cardiac arrest by means of either a dispatcher providing directions to the nearest AED or raising local public awareness; as well as in planning a strategic placement and further development of the AED network. The purpose of the study was to analyse the quality of data collected and visualise the interregional differences in development of AED network, whilst identifying possible limitations in the existing methods of data collection. 
METHODS: 
“AED Database of Slovenia” is an ongoing project, conducted since 2009 by students of Faculty of Medicine, University of Ljubljana, mentored by Department of Anaesthesiology and Reanimatology. Relevant data is publicly available as an interactive web map at www.aed-baza.si.
All data collected in past 10 years up to 5.5.2019 was included in the study. We have analysed the range of variables that are recorded for each indexed AED, including date of entry in the registry, the institution responsible for placement and maintenance, and the exact GPS microlocation using a Geographic Information System (GIS) tool Geopedia.lite. We have cross-referenced the data with Statistical Office of Republic of Slovenia population data and the Surveying and Mapping Authority of the Republic of Slovenia.

RESULTS: 
Image 1: 1608 AED units indexed and displayed on interactive public map (www.aed-baza.si)
Graph 1: Total number of AED units by Statistical Region of Slovenia
Map and Table 1: Average surface area per AED unit by Statistical Region of Slovenia (City Municipalities analysed and displayed separately)
Map and Table 2: Population per AED unit by Statistical Region of Slovenia (City Municipalities analysed and displayed separately)
Map and Table 3: Total number of AED units by Statistical Region of Slovenia (City Municipalities analysed and displayed separately)
Map and Table 4: Population per AED unit by individual Municipality of Slovenia, Overlaid by GPS locations of mapped AEDs

CONCLUSIONS:
Even though nationwide AED coverage appears satisfactory, graphical representations of AED entries reveal a wide inter- and intraregional variation that exceeds deviations expected due to differences in population density and distribution. Methods local communities employ to promote the use of and maintain the AED network also vary greatly, so efforts of maintaining a centralised and up-to-date national registry are well justified.

3 - “AED Database of Slovenia” - An analysis of operation of Slovenian National Public Access Defibrillators Registry