b'2024 DATASETFigure 11 presents a bivariate analysis of survival to hospital discharge rate by EMS response time (measured from call receipt at dispatch center to arrival of the ambulance on scene) for all OHCA patients as well as three subsets: bystander witnessed, bystander witnessed VF/VT (Utstein), and unwitnessed. Patients with a witnessed VF/VT arrest experienced a significant decrease in survival with increasing EMS response time. In contrast, response time had minimal impact on survival among unwitnessed arrests. Figure 11. Survival rate by EMS response time and arrest witness status.38Figure 12. Survival rate by EMS response time and arrest witness status, among patients who received bystander CPR.'