Factors associated with automated external defibrillator use in out-of-hospital cardiac arrest by type of lay rescuers: a Japanese nationwide, population-based descriptive study.

BACKGROUND

Prompt automated external defibrillator (AED) use and shock delivery are crucial for improving outcomes in patients with out-of-hospital cardiac arrest (OHCA). This study was aimed at elucidating the current patterns of AED use by lay rescuers in Japan and exploring the associated factors by lay rescuer type.

METHODS

In this observational study, data from the All-Japan Utstein Registry, a nationwide population-based registry of OHCAs, were analyzed. Patients with OHCA due to nonexternal causes that were witnessed by citizens were included. The primary outcome was AED use, defined as AED pad application, by each bystander witness type. As an exploratory analysis, we performed a multivariable logistic regression analysis of factors that could be associated with AED use.

RESULTS

In total, 33,426 individuals with OHCAs witnessed by citizens were included. Of these individuals, 20,410 were male (61.1%) with a median (interquartile range [IQR]) age of 80 (70, 87) years. AEDs were used in 12.6% of all OHCAs witnessed by citizens; and in 1.1%, 22.5%, and 37.7% of OHCAs witnessed by family members, citizens in public, and others, respectively. Regarding the OHCAs witnessed by citizens in public, female sex, weekends, and nighttime were associated with decreased AED use. Regardless of the witness type, dispatcher instructions and delays in response time were associated with increased AED use.

CONCLUSION

We elucidated the current patterns of AED use in Japan by using a nationwide population-based OHCA registry. We found that patient characteristics and various situational and systemic factors can influence AED use by citizens.