We conducted literature searches, visits to dispatch centers, and interviews with. EMS personnel in order to analyze and study the 911 call and response- ...
Factors leading to delays in the 9-1-1 call and dispatch process James J. Rifino1,3, Narimane Khaled2, Sam Lalezari2, Enrique Salazar2, Rami Shuraim2, 1,3 1,3 1,3 1,3 Stephen P. Wood , Srihari Cattamanchi , Majed Aljohani , Abdulrahman S Alqahtani , Mustapha Fofana1,2, Michael S. Molloy1, Gregory R. Ciottone1,3 Official hospital of the Boston Red Sox
1Harvard Affiliated
Disaster Medicine Emergency Medicine Fellowship, Department of Emergency Medicine, Beth Israel Deaconess Medical Center, Boston, MA 2MIRAD Laboratory Worcester Polytechnic Institute, Worcester, MA 3Department of Emergency Medicine, Beth Israel Deaconess Medical Centre, Boston, MA
INTRODUCTION
RESULTS/DISCUSSION
DATA
Lives depend on the timely response of Emergency Medical Services (EMS) and the quality of care they provide. The world’s population has experienced rapid growth in recent decades and there is a growing effort within the EMS community to meet this demand. This directly impacts how effectively EMS can respond, stabilise and transport the growing number of emergency 9-1-1 calls.
Fig 2: 3yr representation of Boston population vs EMS response
Fig 3: 9-1-1 call process delays
As a result of increased 911 call volume in the United States, intra and inter-agency communication delays have been rising. The response time of EMS providers to medical incidents can be improved if these delays are minimized. Delays result from the complex world of 911 calls and their responding systems. Multiple calls and transmissions from multiple sources filter through a single bifurcation point, the Dispatch Center, which must prioritize 911 calls, and organize rapid and effective ambulance response. National Emergency Number Association states the number of 9-1-1 calls in the United States was approximately 240 million in 2012. A 9-1-1 call is subject to many delays. These delays can be classified into three branches, which are: people, environment, and technology
Distance and call volume are the two main delay factors within the 9-1-1 call process (Fig.3). Distance is part of the environmental delay branch (Fig.6) delays could occur due to the location of the caller, traffic, or weather. Call volume delays are a result of increased population and inefficient technology.
Fig.1: The 9-1-1 Call Process
Each 9-1-1 call goes through a different process depending on which device is used. When using a cellphone, the call is redirected to the nearest cellular tower; while using a landline, the call goes directly to a local dispatch center. Regardless of which device is used to place a 9-1-1 call, the call will eventually go through a similar process. It will first be connected to the call taker, and then the dispatcher who will assign the appropriate response units.
Figure 2 shows a direct relationship between ambulance dispatch time and population. As population increases, 911 call volumes increase making it more difficult for emergency teams to be dispatched in a timely fashion, response time increased for high priority 911 calls from 5.5 minutes to 5.7 minutes, with a relative difference of 12 seconds.
Figures 4 and 5 were derived from the mathematical formula used on data obtained from the national report card in Emergency Medicine.
Dial 9-1-1 Landline
Cellular
Local Dispatch Center
Nearest Cellular Tower
Call Taker Dispatcher
Fig.4: Access to Emergency Care by State, Grouped by Region
Response time delays were broken down into 3 main categories Technology, Environment and People and these were further subdivided as outlined in Fig.6.
IPW-K2SL Solution
Is It A Local Dispatch Center?
Yes
No
Police EMS
Transfer to Local Dispatch Center
VDTD
Fire
OBJECTIVES To outline sources of communication and/or transportation delays experienced by EMS dispatch centers and the variables effecting the rapid and efficient response to 9-1-1 calls.
Fig.5: Quality and Patient Safety by State, Grouped by Region
ADAV
The Variable Dispatch Time Delays (VDTD) are the ones that can be reduced. To do this, the call taker should collect the caller’s information more effectively. The digital checklist created for this project is one of the possible solutions. This checklist contains the Emergency Medical Dispatch Guidecards, detailing the general dispatch procedures that dispatchers should adhere to. Using this method, the call taker has Augmented Data Assimilation Visualization (ADAV) by being able to provide accurate and useful advice more efficiently, which will in return speed up the overall 9-1-1 call process.
METHODS
CONCLUSIONS Response Time
Fig.6: Breakdown of reason for response delay Technology
Environment
People
Language
Culture
Human Error
Psychology
Traffic
Weather
Information
Tools
Communications
We conducted literature searches, visits to dispatch centers, and interviews with EMS personnel in order to analyze and study the 911 call and response-decision making process. We examined response time data collected between 2009-2011 for the city of Boston and the different types of EMS personnel, equipment technology and transportation methods. Control theory was used to analyze delays occurring with the 9-1-1 call process and how delay interaction compounding total delay throughout the process using a nonlinear stochastic control model utilising the Hopf-Markov Decision Process. Using data from the report card on Emergency Medicine a mathematical feedback controller equation was used to construct the main delay equation. This equation helps determine which 9-1-1 call to prioritize, as well as organize the responses and administer rapid interventions or ambulance transportation. To further understand delays several 9-1-1 systems which ameliorate EMS response times currently in use were studied.
IDCC
Delays start accumulating from the moment a 9-1-1 call is placed, until help is provided at either the emergency scene or a hospital. Ideally, the time response should be kept under seven minutes. Thus, the call taker needs to obtain the caller’s information in an effective manner by asking the appropriate questions. This also applies to the caller, who should be prepared to provide useful information.
Improving 9-1-1 response times is vital for an efficient and effective emergency response service. Out of the systems analyzed, those equipped with real-time GPS, real-time system overview, compatibility with Computer Aided Dispatch, and emergency vehicle preemption are the most useful. The nationwide implementation of such 9-1-1 systems should be supported. Additionally, the interface of the digitized checklist created for this project should be developed and researched further.
