[Discussion on automated external defibrillator configuration optimization strategy of rapidly developing city: a...

To explore the automated external defibrillator (AED) configuration optimization strategy in line with the characteristics of the rapidly developing cities by analyzing the actual coverage of AED in Bao'an District based on the real world data of out-of-hospital cardiac arrest (OHCA) in Bao'an District, Shenzhen City.

The data of cardiac arrest database registered in Bao'an District of Shenzhen City from March 1, 2019 to February 29, 2020 were included in a retrospective observational study. The AED coverage of public and non-public areas was analyzed by calculating the minimum distance between the occurrence place of each OHCA event and the nearest AED. The minimum distance ≤ 100 m was set as AED coverage, and the minimum distance > 100 m was set as non-AED coverage. It was assumed that one AED was configured for each OHCA hotspot area, then the AED coverage changes were analyzed. Based on the actual situation that the AED in schools, governments, sports venues, subways, tourist attractions and parks of public areas in Bao'an District could not be obtained at any time within 24 hours, it was assumed that all AED in the public areas could be obtained at any time within 24 hours, the impact of AED available at any time on AED coverage was analyzed.

A total of 525 cases of OHCA were enrolled. The highest incidence of OHCA was found in residential and industrial areas [54.5% (286/525) and 14.3% (75/525), respectively]. There were 252 AED in Bao'an District, Shenzhen, and 115 OHCA events occurred within the coverage area of AED. Even if all AED met the ideal state that could be obtained at any time within 24 hours, the coverage rate was only 21.9% (115/525). The AED coverage rate of the public areas and non-public areas was 31.6% (37/117) and 19.1% (78/408) respectively, with uneven distribution, and the AED coverage rate of non-public areas was low. Assuming that the residential community and industrial zone with more than 2 OHCA cases were respectively equipped with one AED, the coverage rate of AED in the non-public areas increased from 19.1% (78/408) to 28.2% (115/408), basically meeting the requirement that AED could be obtained at any time when OHCA events occurred. Some AED in the public areas of Bao'an District were not available at any time within 24 hours. If the ideal state that all AED in the public area could be obtained at any time within 24 hours could be achieved, the AED coverage rate of all regions increased from 16.8% (88/525) to 21.9% (115/525), the AED coverage rate of the public areas increased from 29.1% (34/117) to 31.6% (37/117), the AED coverage rate of the non-public areas increased from 13.2% (54/408) to 19.1% (78/408).

AED configuration in Bao'an District was unevenly distributed, and the coverage rate of AED in non-public areas was low. The allocation strategy for AED in fast-growing cities like Shenzhen should be as follows: on the premise of ensuring AED availability for 24 hours, priority should be given to covering the number of AED in the non-public areas including residential communities and industrial zones; AED is available in the public areas for 24 hours.