Barriers to successful dispatcher-assisted cardiopulmonary resuscitation in out-of-hospital cardiac arrest in Korea

Dispatcher-assisted cardiopulmonary resuscitation (DA-CPR) improves bystander CPR rates and survival outcomes. This study aimed to identify barriers to successful DA-CPR in patients with out-of-hospital cardiac arrest (OHCA). This retrospective observational study used data from a nationwide OHCA database from 2017 to 2021. Adult emergency medical services (EMS)-treated patients with OHCA with a presumed cardiac etiology were enrolled. The main exposure variable was compliance with DA-CPR. The primary outcome was good neurological recovery at hospital discharge. Multivariable logistic regression analysis was conducted to identify the major factors associated with unsuccessful DA-CPR with and without multiple imputations. Causal mediation analysis was conducted using witnessed status as a mediator. In the final analysis, 49,165 patients with OHCA were included. A total of 36,865 (75.0%) patients successfully underwent DA-CPR. A higher proportion of good neurological recovery was observed in the successful DA-CPR group than in the non-successful DA-CPR group (P 65 years, male sex, OHCA occurring in a non-metropolitan area or private place, unwitnessed status, whether the bystander was a non-family member or non-cohabitant, female sex or had not received CPR training, and primary call dispatchers not receiving any first-aid training. Additional analyses after multiple imputations showed similar results. Mediation effect was significant for most risk factors for unsuccessful DA-CPR. Bystander characteristics (non-family member or non-cohabitant, female, and uneducated status for CPR) and primary call dispatchers not receiving first-aid training were identified as risk factors for unsuccessful DA-CPR.