Effect of citywide enhancement of the chain of survival on good neurologic outcomes after out-of-hospital cardiac arrest from 2008 to 2017.

Improving outcomes after out-of-hospital cardiac arrests (OHCAs) requires an integrated approach by strengthening the chain of survival and emergency care systems. This study aimed to identify the change in outcomes over a decade and effect of citywide intervention on good neurologic outcomes after OHCAs in Daegu. This is a before- and after-intervention study to examine the association between the citywide intervention to improve the chain of survival and outcomes after OHCA. The primary outcome was a good neurologic outcome, defined as a cerebral performance category score of 1 or 2. After dividing into 3 phases according to the citywide intervention, the trends in outcomes after OHCA by primary electrocardiogram rhythm were assessed. Logistic regression analysis was used to analyze the association between the phases and outcomes. Overall, 6203 patients with OHCA were eligible. For 10 years (2008-2017), the rate of survival to discharge and the good neurologic outcomes increased from 2.6% to 8.7% and from 1.5% to 6.6%, respectively. Especially for patients with an initial shockable rhythm, these changes in outcomes were more pronounced (survival to discharge: 23.3% in 2008 to 55.0% in 2017, good neurologic outcomes: 13.3% to 46.0%). Compared with phase 1, the adjusted odds ratio (AOR) and 95% confidence intervals (CI) for good neurologic outcomes was 1.20 (95% CI: 0.78-1.85) for phase 2 and 1.64 (1.09-2.46) for phase 3. For patients with an initial shockable rhythm, the AOR for good neurologic outcomes was 3.76 (1.88-7.52) for phase 2 and 5.51 (2.77-10.98) for phase 3. Citywide improvement was observed in the good neurologic outcomes after OHCAs of medical origin, and the citywide intervention was significantly associated with better outcomes, particularly in those with initial shockable rhythm.