Do warning lights and sirens reduce ambulance response times?
OBJECTIVE: To determine the time saving associated with lights and siren (L&S) use during emergency response in an urban EMS system. METHODS: This prospective study evaluated ambulance response times from the location at time of dispatch to the scene of an emergency in an urban area. A control group of responses using L&S was compared with an experimental group that did not use L&S. An observer was assigned to ride along with ambulance crews and record actual times for all L&S responses. At a later date, an observer and an off-duty paramedic in an identical ambulance retraced the route–at the same time of day on the same day of the week–without using L&S and recorded the travel time. Response times for the two groups were compared using paired t-test. RESULTS: The 32 responses with L&S averaged 105.8 seconds (1 minute, 46 seconds) faster than those without (95% confidence interval: 60.2 to 151.5 seconds, p = 0.0001). The time difference ranged from 425 seconds (7 minutes, 5 seconds)
