Out-of-Hospital Cardiac Arrest in Ireland 2012 to 2020: Bystander CPR, bystander defibrillation and survival in the Utstein comparator group

Background: The Irish Out-of-Hospital Cardiac Arrest registry (OHCAR) collects data based on the internationally recognised Utstein template. The Utstein comparator group (bystander witnessed and initial shockable rhythm) has specific relevance in benchmarking out-of-hospital cardiac arrest (OHCA) health system performance. Aims: To describe OHCA in the Utstein comparator group during 2012 to 2020 in Ireland. To explore predictors of bystander CPR, defibrillation, and survival to hospital discharge. Methods: National level OHCA registry data were interrogated. The subset of patients in the Utstein comparator group were identified and explored. Multivariable logistic regression was used to model outcome predictors. Results: There were 3,092 cases of OHCA in the Utstein comparator group during 2012 to 2020. Overall survival to hospital discharge was 27%. On average there were yearly improvements in bystander CPR, bystander defibrillation, and survival. Bystander CPR was associated with a 57% increase, while bystander defibrillation was associated with a 78% increase in the adjusted odds of survival to hospital discharge. The adjusted odds of both bystander CPR and defibrillation were higher in rural areas, despite decreased survival in these communities when compared to urban. OHCA that occurred at home was associated with decreased odds of bystander CPR, bystander defibrillation, and survival to hospital discharge. Conclusions: Bystander CPR, bystander defibrillation and survival to hospital discharge have increased in the Utstein comparator group during 2012-2020 in Ireland. Bystander CPR and defibrillation remain key modifiable health systems targets to increase overall OHCA survival.