Paramedic-assessed quality of bystander CPR is associated with survival in out-of-hospital cardiac arrest.

Abstract

Bystander CPR (bCPR) is known to improve survival from out-of-hospital cardiac arrest (OHCA). Data on the impact of quality of bCPR is limited and dated. The NSW Ambulance OHCA registry captures data on the quality of CPR provided by bystanders prior to EMS arrival. We sought to determine the impact of bCPR quality on 30-day survival in our region. A population-based registry study was performed on cases occurring between 2021 and 2024. Bystander CPR was included in multivariate models as a dichotomous variable or stratified by bCPR quality, and compared with no bCPR. In all, 17,715 patients were included in the study. Bystander CPR was performed in 59.4% of cases and bCPR quality was recorded in 62.1%. Performance of bCPR was associated with a 70% increase in the odds of achieving 30-day survival (aOR = 1.70, 95% CI: 1.24-2.34). Good-quality bCPR was associated with a greater increase in the odds of survival (aOR = 2.62, 95% CI: 1.86-3.68) while poor-quality bCPR was not associated with 30-day survival (aOR = 0.99, 95% CI: 0.68-1.45). Younger age, witnessed arrest and non-residential location were associated with increased odds of bCPR being performed and being of good quality. Male sex and EMS response time less than 10 min were associated with lower odds of bCPR being performed but were not associated with quality of bCPR. Quality of bCPR is of greater importance than the fact that bCPR was performed. EMS systems and policy-makers should consider measures that support providers of bCPR to deliver effective compressions.