Effect of Dispatcher-Assisted Cardiopulmonary Resuscitation Program and Location of Out-of-Hospital Cardiac Arrest on Survival and Neurologic Outcome.

STUDY OBJECTIVE We study the effect of a nationwide dispatcher-assisted cardiopulmonary resuscitation (CPR) program on out-of-hospital cardiac arrest outcomes by arrest location (public and private settings). METHODS All emergency medical services (EMS)-treated adults in Korea with out-of-hospital cardiac arrests of cardiac cause were enrolled between 2012 and 2013, excluding cases witnessed by EMS providers and those with unknown outcomes. Exposure was bystander CPR categorized into 3 groups: bystander CPR with dispatcher assistance, bystander CPR without dispatcher assistance, and no bystander CPR. The endpoint was good neurologic recovery at discharge. Multivariable logistic regression analysis was performed. The final model with an interaction term was evaluated to compare the effects across settings. RESULTS A total of 37,924 patients (31.1% bystander CPR with dispatcher assistance, 14.3% bystander CPR without dispatcher assistance, and 54.6% no bystander CPR) were included in the final analysis. The total bystander CPR rate increased from 30.9% in quarter 1 (2012) to 55.7% in quarter 4 (2014). Bystander CPR with and without dispatcher assistance was more likely to result in higher survival with good neurologic recovery (4.8% and 5.2%, respectively) compared with no bystander CPR (2.1%). The adjusted odds ratios for good neurologic recovery were 1.50 (95% confidence interval [CI] 1.30 to 1.74) in bystander CPR with dispatcher assistance and 1.34 (95% CI 1.12 to 1.60) in bystander CPR without it compared with no bystander CPR. For arrests in private settings, the adjusted odds ratios were 1.58 (95% CI 1.30 to 1.92) in bystander CPR with dispatcher assistance and 1.28 (95% CI 0.98 to 1.67) in bystander CPR without it; in public settings, the adjusted odds ratios were 1.41 (95% CI 1.14 to 1.75) and 1.37 (95% CI 1.08 to 1.72), respectively. CONCLUSION Bystander CPR regardless of dispatcher assistance was associated with improved neurologic recovery after out-of-hospital cardiac arrest. However, for out-of-hospital cardiac arrest cases in private settings, bystander CPR was associated with improved neurologic recovery only when dispatcher assistance was provided.