Background: A recently published study has shown that survival after out-of-hospital cardiac arrest (OHCA) in Göteborg is almost three times higher than in Stockholm. The aim of this study was to investigate whether in-hospital factors were associated with outcome in terms of survival.
Methods: All patients suffering from OHCA in Stockholm and Göteborg between January 1, 2000 and June 30, 2002 were included. The two groups were compared with reference to patient characteristics, medical history, pre-hospital and hospital course (including in-hospital investigations and interventions) and mortality. All medical charts from patients admitted alive to the different hospitals were studied. Data from the Swedish National Register of Deaths regarding long-term survival were analysed. Pre-hospital data were collected from the Swedish Ambulance Cardiac Arrest Register.
Results: In all, 1542 OHCA in Stockholm and 546 in Göteborg were registered during the 30-month study period. In Göteborg, 28% (153 patients) were admitted alive to the two major hospitals whereas in Stockholm 16% (253 patients) were admitted alive to the seven major hospitals (p<0.0001). On admission to the emergency rooms, a larger proportion of patients in Stockholm was unconscious (p=0.006), received assisted breathing (p=0.008) and ongoing CPR (p=0.0002). Patient demography, medical history, in-hospital investigations and interventions and in-hospital mortality (78% in Göteborg, 80% in Stockholm) did not differ between the two groups. Various pre-hospital time intervals were significantly longer in Stockholm than in Göteborg. Total survival to discharge after OHCA was 3.3% in Stockholm and 6.1% in Göteborg (p=0.01).
Conclusion: An almost 2-fold difference in survival after OHCA between Stockholm and Göteborg appears to be associated with pre-hospital factors only (predominantly in form of prolonged intervals in Stockholm), rather than with in-hospital factors or patient characteristics.