The Relationship Between the Time-distribution of EMS Demands and the Transport Time of 119 Ambulances

ABSTRACT

PURPOSE: As the prevalence of emergency diseases such as cardiac, cerebrovascular and respiratory disease has increased, the demands on the emergency medical service (EMS) system have also increased. But the resource of the EMS can't be expanded to meet the increased demands. So, due to the limited resources and the increased EMS call volume, the efficacy of EMS has decreased. In this study, we analyzed the relationship between the call volume and EMS transport time with respect to the EMS efficacy. METHODS: We retrospectively reviewed the computerized log data of the EMS ambulances in a metropolitan city of Korea. During the period from January 2008 to December 2008, a total 74,349 EMS calls developed and in 50,661 cases an EMS ambulance was dispatched to transport patients to a hospital. The time-distribution of the EMS demands and the time of EMS ambulance transport were analyzed according to the date, time and location of the calls to the EMS. Other characteristics of the EMS such as triage and disease or injury were analyzed. The transport time of the dispatched ambulance was compared between within the jurisdiction and outside the jurisdiction for evaluating the efficacy of the EMS system. RESULTS: During dawn (0000-0800) the frequency of EMS calls was low, as compared with that of the day and night (0800-2400). During dawn, 12,098 (23.88%) patients were developed, but 38,563 (76.12%) patients were developed during the day and night. On comparison according to jurisdiction, the response time and total transport time of the ambulance dispatched within the jurisdiction were faster than that outside the jurisdiction (p<0.001). During day and night, more ambulances were dispatched outside the jurisdiction that that during dawn (p<0.001). CONCLUSION: In a situation that there are many simultaneous demands for EMS in the same area, insufficient EMS resources can't quickly and effectively service all the demands. So, the time-distribution of EMS calls can assessed according to the dispatched EMS ambulances. Using our data, EMS resources can be redistributed to increase the efficiency of EMS.