Evaluation and Optimization of Automated External Defibrillator Deployment: Comparing Straight-Line and Walking-Route Distances for Out-of-Hospital Cardiac Arrests

BackgroundThis study aimed to explore appropriate automated external defibrillator (AED) deployment strategies for Gamma cities, addressing the gap in research. By comparing the coverage of AEDs under different calculation models, we evaluated the rationality of the distribution of the AEDs in a Gamma city within eastern China and provided suggestions for improvement. MethodsThis observational study used two datasets (an AED inventory and an OHCA registry) to calculate the average distance between out-of-hospital cardiac arrest (OHCA) cases and the nearest AED, and assess AED coverage rates based on straight-line and walking-route models. A total of 1,350 OHCA cases and 1,238 AEDs were included. ResultsThe average emergency radius per AED was 497.96 m. The average walking-route and straight-line distance between OHCAs and the nearest AED were 407.09 and 378.94 m, respectively. The AED coverage rate within 100 m was 8.30% and 7.33% based on the straight-line model and walking-route model, respectively. The coverage rate within the golden six minutes for resuscitation using the walking-route model was 39.26%. ConclusionsThe AED distribution throughout the studied city was generally well-organized, with a large number of devices within close proximity and good coverage. However, a significant standard deviation was noted, indicating a clear clustering rather than a uniform distribution. The coverage rate within the golden six minutes was moderate. However, in an urban environment, the straight-line model may underestimate the average distance and overestimate the coverage. Hence, the walking-route-based model may be more helpful considering the critical nature of OHCA.