Rural-urban differences for integrated first responder and drone automated external defibrillator delivery in North Carolina.

BACKGROUND

Early defibrillation for out-of-hospital cardiac arrest (OHCA) improves survival, but timely automated external defibrillator (AED) access remains challenging especially in rural areas. We conducted a computational modelling study to estimate how existing urban-rural differences in AED arrival would change for a proposed first responder (FR) and drone-based AED delivery program in regions with large geographical variation.

METHODS

We included North Carolina counties with ≥10 OHCAs per year in both rural and urban census tracts between Jan. 2013 - Dec. 2019. We modelled a proposed intervention in which FRs were given AEDs and drone-AED networks were optimized within each county to maximize 3, 5, or 7-minute AED arrival to OHCAs.

RESULTS

We included 19 counties and 8,955 OHCAs (5,754 urban, 3,201 rural). The median historical county-level median AED arrival time was 6.6 mins [IQR: 6.1-7.1] in urban areas and 9.2 mins [IQR: 8.0-10.2] in rural areas. Drone-AED networks optimized for 5-minute AED arrival reduced median AED arrival time to 4.0 mins [IQR: 3.8-4.3] in urban areas and 7.0 mins [IQR: 6.0-8.0] in rural areas. Five-minute AED arrival rates improved from 19.9% [IQR: 15.7-23.2%] to 75.0% [IQR: 70.9-85.6%] for urban areas and from 7.6% [IQR: 4.6-9.5%] to 15.8% [IQR: 11.3-32.9%] for rural areas. Optimizing for 7-minute AED arrival increased the rural-urban response gap to a lesser extent.

CONCLUSIONS

When optimized for 3-, 5- or 7-minute AED arrival, proposed FR- and drone-based AED deployment would improve AED arrival times in urban areas more than rural areas. Additional optimization approaches are needed to reduce inequality between urban and rural defibrillation arrival times in areas with large geographic variation.