Effect of response times on survival from out-of-hospital cardiac arrest: using geographic information systems

We explored how different response times from out-of-hospital cardiac arrest (OHCA) to defibrillation in the County of Stockholm, Sweden, affect patients’ survival rates. This was done by combining a geographic information systems (GIS) simulation of driving times with register data on survival rates. The emergency resources comprised ambulance alone and ambulance plus fire services. The simulation model predicted a baseline survival rate of 3.9 percent, and reducing the ambulance response time by one minute increased survival to 4.6 percent. Adding the fire services as first responders (dual dispatch) increased survival to 6.2 percent from the baseline level. The model predictions were vali-dated using empirical data.