AMBULANCE ARRIVAL TO PATIENT CONTACT - THE HIDDEN COMPONENT OF PREHOSPITAL RESPONSE-TIME INTERVALS

Study objective: To determine the time between ambulance arrival at the scene to paramedic arrival at the patient (arrival to patient contact) and the effect of barriers to paramedic movement on this time interval. Design: A prospective, observational study. Time intervals were collected by independent third-party riders on emergency (Code 1 and Code 2) calls. Potential barriers to paramedic movement were recorded. Setting: Public utility model urban emergency medical services system. Type of participants: Two hundred thirty-two emergency ambulance calls were observed, and data were analyzed from 216. Interventions: None. Results: The median arrival-to-patient contact interval for all calls was 1.33 minutes (interquartile range, 0.67 to 4.13 minutes). Barriers prolonged the arrival-to-patient contact interval (P<.001, Kolmogorov-Smirnov test). The median arrival-to-patient contact interval was 2.29 minutes (1.01 to 4.82 minutes) for 122 runs with barriers and 0.82 minutes (0.37 to 1.96 minutes) for 94 runs without barriers. Conclusion: The arrival-to-patient contact interval adds a variable and potentially lengthy amount of time to the total prehospital response time interval, and barriers impeding paramedic movement to the patient prolong this time interval. In 25% of all observed paramedic calls, the arrival-to-patient contact interval was more than four minutes. Measurement of the time from ambulance arrival on the scene to paramedic arrival at the patient is necessary to appropriately determine the relationship among total prehospital response time, paramedic interventions, and patient outcome.