Abstract
We constructed a prototype community first responder (CFR) dispatch system. The system sends incident information, including a map, to the chosen CFR's mobile phone. We tested it in a simulation of 30 out-of-hospital cardiac arrest incidents which had occurred in the town of Motegi during the previous year. Thirty off-duty firefighters acted as CFRs and were sent to the same locations. The mean response time (from the CFR receiving dispatch information to arrival at the scene) was 3 min 37s faster than the actual response time in the corresponding historical control, i.e. the response time was reduced by 36% (P < 0.01). The median travel distance of the CFRs was 3.4 km and there was a positive correlation between response time and travel distance. The study showed that interactive communication between dispatcher and CFR was important for effective operation and that CFRs could reach an OHCA patient before the Emergency Medical Service arrives.
Introduction
Early resuscitation and defibrillation improves the survival rate for out-of-hospital cardiac arrest (OHCA) patients.1,2 Guidelines for resuscitation recommend a public access defibrillation (PAD) programme, including the use of first responders who can arrive at the patient earlier than the Emergency Medical Service (EMS). These measures can increase survival rates. 3 Community first responders (CFR) are local volunteers who are dispatched by the EMS to provide early resuscitation before an ambulance crew arrives. Several studies have shown that CFRs improve the survival rate of OHCA patients.4,5 However, the CFR system has not yet been implemented in Japan.
We have investigated the elements necessary to introduce a CFR system in Japan. 6 The dispatch system is a critical factor since it affects overall response times. We have constructed a prototype CFR dispatch system and examined whether it can reduce response times.
Methods
We customised a cloud-based location service (Novi-p.com Corporation Tokyo, Japan) which enabled us to observe the location of members who had mobile phones with GPS functions (Figure 1). Mobile phone types that could receive dispatch information from the system were smart phones with the Android operating system or Apple devices with the iOS operating system. The CFRs had to download the special application to their mobile phone, and then enter certain information (name, mobile phone number, email address).
The basic operations screen. Dispatchers can initiate dispatch and manage various settings. The dispatcher can also check the movement of the CFR.
In the dispatch centre we used a notebook computer with the Windows 7 operating system. To send a dispatch message to the CFR, the dispatcher needs to know each CFR’s email address, mobile phone number and distance from the incident in advance. Information about the locations of Automated External Defibrillators (AEDs) can also be recorded (Figure 2) in the system but we did not use that in the present experiments.
Setting screens. (a) Screen of a registered CFR. (b) CFR’s personal screen. The dispatcher enters the email address and mobile phone number on this screen. (c) Group setting screen. The dispatcher can pre-set the distance from a patient to determine which CFRs within this particular range should be dispatched.
The current status of the CFR (‘dispatch possible’, ‘dispatch impossible’, ‘dispatched’, ‘arrived’) can be seen on the status screen (Figure 3). When a CFR sets their status to ‘dispatch possible’ the phone sends GPS position information to the server at one-minute intervals. Location information is not updated if the status is set to ‘dispatch impossible’.
The CFR's mobile phone screen. (a) Standby screen. GPS position information is sent every minute when CFR dispatch is possible (b) CFR status setting screen. Possible status values are “dispatch possible “, “dispatch impossible”, “dispatched” and “arrived”.
When responding to an emergency, the dispatcher enters the address of the incident, the household name and other information (Figure 4). The system automatically selects CFRs who are available within a pre-set distance from the patient. The screen allows the dispatcher to select which CFR is closest to the patient and who should respond. If desired, the dispatcher can also select CFRs who are outside the pre-set distance from the patient. The input information will appear on the chosen CFR's mobile phone as a text message with a map of the patient’s location if the CFR has activated the Google map link (Figure 5).
The CFR's dispatch command screen. The CFR who is closest to the incident address is automatically selected (shown in bold outline.) Map information and the entered text is transmitted to the CFR. The dispatch command message and the map screen. (a) Messages from the dispatcher are automatically displayed when they arrive. (b) A map (Google map) can also be displayed.
When a CFR changes their status to “Dispatched”, the dispatcher can confirm that the CFR is heading towards the patient. The dispatcher can also instruct a particular CFR to pick up an AED as required (Figure 6).
Screen to check the dynamics of CFR. A message is sent to all CFRs within the circle who are able to respond. The radius can be set by the dispatcher. The dispatcher can confirm which CFR is responding from the colour of the icon.
Simulations
We performed simulation studies in the town of Motegi, Tochigi prefecture (Figure 7) which is a future candidate site for CFR operations. Motegi has a population of 14,600, an area of 172 km2 and is a typical rural area of Japan. During two days in April 2013, 30 off-duty firefighters acted as CFRs. In routine, operational use, we assume that a dispatcher would send the response order to the CFR immediately after the EMS has been dispatched. In the simulation, we used 30 OHCA incidents which had occurred at Motegi in the year of 2012. All these cases (i.e. historical controls) occurred inside people's homes. The CFRs received alarms only if they were within a distance of 3 km from the place of the simulated arrest. The CFRs went to the scene using their private cars. In the dispatch information, we sent the patient’s address and the householder’s name, and occasionally sent directions to help locate the patient.
Study area.
The study was approved by the appropriate ethics committee.
Data collection and statistics
We measured the time from typing the patient information into the dispatch computer to sending the information to CFRs (the data input time). We also measured the time from sending the dispatch information to the CFR's arrival on the scene. The travel distances of the CFRs were also measured. The time intervals for each simulated alarm were compared to the actual EMS time intervals for the corresponding historical control. Differences between time intervals were analysed with the Mann-Whitney U-test. Time intervals and travel distance of the CFRs were analysed with Spearman’s correlation.
Results
Results of 30 simulations compared to historical controls.
The mean travel distance of CFRs was 3.4 km (range 0.2–7.2). There was a positive correlation between response time and travel distance of the CFRs (Figure 8).
Total travel distances of the dispatched CFRs and their response times.
Discussion
In Japan, the number of AED devices increased rapidly after 2004 when AED use by citizens was approved by the government. By December 2011, about 330,000 AEDs had been installed. 7 As well as having AEDs available, it is also important to have a PAD programme if the survival of patients with cardiopulmonary arrest is to be improved. Community first responders are an important element of PAD programmes. For effective CFR operation, an appropriate dispatch system is required. First responders usually receive a dispatch order by a pager, via an email message, radio or mobile phone. A dispatch system which relies on commonly available resources in the community may be more successful than one which requires sophisticated technology. We developed a method of using commonly available devices to transmit dispatch orders quickly to CFRs. Our study showed that CFRs could reach an OHCA patient before the EMS arrives.
Two previous studies reported the effectiveness of a mobile phone’s SMS message and GPS function for communication between a CFR and a dispatcher.8,9 In these studies, only the address of the OHCA patient was sent to the CFR. Unsurprisingly there were problems when the address-only information was not sufficient to find the exact location of the patient. Therefore it was suggested that other information, such as directions and a map, should be added. When a first responder has to ask the dispatcher for the exact location, the response time is lengthened. Therefore, map information is indispensable to rapid CFR response.
Furthermore, in the previous studies, there was one-way delivery of information from the dispatcher to the CFR. The dispatcher issued the dispatch order but was not able to see whether the CFR had actually responded. When a PAD programme is in operation, it is important to know who is obtaining the AED. Recently, mobile phone apps that can locate AEDs have been developed. 10 On the other hand, there is no published information about who is the best person to obtain an AED to achieve the most effective results with OHCA patients. Furthermore, most AEDs in Japan are installed in public facilities. Since most OHCA events occur in residential locations, these public AEDs are not well sited, so CFRs who can pick up an AED and take it to the incident site are more effective for OHCA patients. 12 Sending AED location information from the dispatcher to the CFR is not enough. The dispatcher must select a specific CFR and give the order to obtain an AED. Therefore, the dispatcher must know whether the CFR is really responding or not and which AED is nearest to the CFR. Our dispatch system allows two-way communication, which means that the dispatcher is able to know that the dispatched CFR is really present at the scene and whether the CFR has an AED or not.
Our prototype system was separate from the dispatch system of the EMS so additional information input was necessary. Even so, the CFRs were able to arrive before the EMS. However, a system which can dispatch both CFRs and EMS simultaneously would obviously be desirable for the shortest response times.
The optimum action area of a CFR is not clear. For effective defibrillation, there is a report that it is necessary for the CFR to arrive at an OHCA patient within 8 min. 11 The distance that a CFR can move in 8 min is calculated as 3300 m from the results of this study, which seems to be appropriate. In areas where an ambulance takes a long time to arrive, it may still be better to dispatch a CFR even if they take more than 8 min to arrive. However, early arrival of the CFR may be better for OHCA patients. Additional investigations about the CFR area and response time are required.
Study limitations
The present study was completed under simulated conditions. In real life, we do not know how quickly a CFR can actually be dispatched. Further delays may occur in conditions of poor mobile phone reception.
Conclusion
We developed a communication system for CFRs in Japan. Rapid response times were possible by transmitting both address and map information. Interactive communication was helpful for good cooperation between between dispatcher and CFR.
Footnotes
Acknowledgements
We thank the community members of Shioya town and the EMS personnel of the Haga and Kaga Fire Departments who initiated the project and made it possible. The research was partially funded by the Promotion Program for Scientific Fire and Disaster Prevention Technologies of the Fire and Disaster Management Agency of Japan (grant number 43).