A Time-Motion Study of the Emergency Medical Services Turnaround Interval

Abstract

Study objective: Because overall EMS system response depends on ambulance availability, we conducted a prospective study of the EMS turnaround interval. This interval represents the time elapsed from ambulance arrival at the hospital until the ambulance reports back in service. Methods: An on-site observer, while monitoring EMS radio traffic, recorded the delivery and recovery activities of personnel from a large urban EMS system at a university hospital emergency department. System policy permitted a maximum turnaround interval of 30 minutes. Prospectively defined subintervals were analyzed. Results: A convenience sample of 122 patient deliveries was collected. Observed and radio-reported times of arrival at the hospital differed by -1′24" to +11'08". In 18.9% of cases, arrival was reported on radio more than 5 minutes after the observed arrival. Time from arrival to removal of the patient from the ambulance averaged 59" (range, 13" to 2′53"), and time from patient removal to emergency department entry averaged 42" (range, 10" to 5′22"). Time from ED entry to placement of the patient on an ED bed averaged 2′11" (range, 33" to 9′35"). Although the mean interval for the verbal report to ED staff was 33" (range, 13" to 2′53"), it was 15" or less in 36% of cases. Writing the ambulance call report took an average of 17′12" (range, 5′20" to 52′11"). The mean time off radio was 29′51" (range, 11′43" to 53′37"), and the mean time the ambulance was actually at the ED was 30′01" (range, 11′25" to 1°17′53"). Observed and radio-reported ambulance departure times differed by -4′31" to +23′32". In 22% of cases, departure was reported by radio more than 5′ after actual departure. Conclusion: In this system, ambulance call report documentation required the greatest subinterval of turnaround interval. The turnaround interval and its subintervals varied widely, and radio contact times correlated poorly with observed times at the ED. Attempts at improvement of overall system response through active management of the turnaround interval may be frustrated by reliance on radio-reported availability. [Cone DC, Davidson SJ, Nguyen Q: A time-motion study of the emergency medical services turnaround interval. Ann Emerg Med February 1998;31:241-246.]