Figure 3From: Developing an analytical tool for evaluating EMS system design changes and their impact on cardiac arrest outcomes: combining geographic information systems with register data on survival rates Proportion of OHCA patients alive (1 month) with VF on first ECG in relation to time from OHCA to defibrillation. Notes: From SCAR. The last proportion (31+) includes all cases above 31 minutes. Number of observations=6156 (1990–2006). Back to article page