European first responder systems and differences in return of spontaneous circulation and survival after out-of-hospital cardiac arrest: A study of registry cohorts

Background: In Europe, survival-rates after out-of-hospital cardiac arrest (OHCA) vary widely between regions. Whether a system dispatching First Responders (FRs; main FR-types: firefighters, police officers, citizen-responders) is present or not may be associated with survival-rates. This study aimed to assess the association between having a dispatched FR-system and rates of return of spontaneous circulation (ROSC) and survival across Europe. Methods: Results of an inventory of dispatched FR-systems for OHCA in Europe were combined with aggregate ROSC and survival data from the EuReCa-TWO study and additionally collected data. Regression analysis (weighted on number of patients included per region) was performed to study the association between having a dispatched FR-system and ROSC and survival-rates to hospital discharge in the total population and in patients with shockable initial rhythm, witnessed OHCA and bystander cardiopulmonary resuscitation (CPR; Utstein comparator group). For regions without a dispatched FR-system, the theoretical survival-rate if a dispatched FR-system would have existed was estimated. Findings: We included 27 European regions. There were 15,859 OHCAs in the total group and 2,326 OHCAs in the Utstein comparator group. Aggregate ROSC and survival-rates were significantly higher in regions with an FR-system compared to regions without (ROSC: 36% [95%CI 35%-37%] vs. 24% [95%CI 23%–25%]; P<0.001; survival in total population [N=15.859]: 13% [95%CI 12%–15%] vs. 5% [95%CI 4%–6%]; P<0.001; survival in Utstein comparator group [N=2326]: 33% [95%CI 30%–36%] vs. 18% [95%CI 16%–20%]; P<0.001), and in regions with more than one FR-type compared to regions with only one FR-type. All main FR-types were associated with higher survival-rates (all P