Regional deprivation and out‐of‐hospital cardiac arrest outcomes: Moderated mediation by call‐to‐emergency department time and bystander resuscitation
So Yeon Kong, Seungmin JeongAbstract
Background
To evaluate whether delayed emergency department (ED) arrival mediates the association between regional deprivation and outcomes after out‐of‐hospital cardiac arrest (OHCA), and whether this mediation differs by bystander cardiopulmonary resuscitation (CPR).
Methods
Using the Korean nationwide OHCA registry (2015–2022), we included emergency medical services‐transported witnessed arrests of presumed cardiac etiology among adults aged 18–80 years ( n = 54,754). Regional deprivation was defined using a census‐based deprivation index (most deprived 20% vs remaining 80%). The mediator was call‐to‐ED arrival time (>30 vs ≤30 minutes). Outcomes were mortality and death or unfavorable neurological outcome at discharge (Cerebral Performance Category 3–5). Multivariable logistic regression and counterfactual‐based causal mediation analyses were adjusted for age, sex, year of occurrence, insurance type, prehospital shockable rhythm, and arrest location, and stratified by bystander CPR.
Results
Deprived areas had higher odds of mortality (aOR 1.58; 95% CI 1.41–1.77), which attenuated after accounting for delayed arrival (aOR 1.45; 1.29–1.62). For the composite outcome, corresponding aORs were 2.30 (1.96–2.70) and 2.15 (1.83–2.53). Delayed arrival mediated 24.33% (95% CI 18.85–29.82) of the deprivation–mortality association and 10.69% (8.28–13.09) of the deprivation–composite association. Mediated proportions were higher with bystander CPR than without bystander CPR (mortality 44.12% vs 19.60%; composite 24.03% vs 7.24%).
Conclusion
Regional deprivation was associated with worse discharge outcomes after OHCA, partly through delayed ED arrival, with stronger mediation when bystander CPR was provided.