ABSTRACT

Introduction: This study represents a first attempt to classify a subset of time-to-dispatch in a 911 center – the call prioritization time. This time is defined as the time required to gather critical case information, after the address is obtained, and prior to notifying responder units of the call. This study characterizes call prioritization time in nine different 911 centers, all using the Fire Priority Dispatch System (FPDS). Times were examined by individual agency, overall, Methods: This was a retrospective, non-controlled, descriptive study involving nine 911 and by FPDS Priority Level.

Objectives: The primary objective in this study was to determine call prioritization time by FPDS Priority Level, Chief Complaint type, individual agency, and all agencies overall.

Results: Over 200,000 cases (n=205,324) cases were studied (Figure 1). Median call prioritization time for all cases was 52 seconds. 96.2 percent of all cases had a time of 120 seconds or less, and 99.2% of all cases had a time of 180 seconds or less. The most time critical calls – ECHO and DELTA – were prioritized in 90 seconds or less, 90% of the time.

Conclusions: Call prioritization times varied significantly by Chief Complaint, FPDS Priority Level, and agency. The highest Priority Level (ECHO) had the shortest median call prioritization time (18 seconds) while the BRAVO level priority had the longest (55 seconds). Future research will investigate the ability of the FPDS to handle specific call types—particularly Structure Fires—within time standards set by the NFPA and ISO, and create better time standards that better define the differences in call evaluation processes.

INTRODUCTION

In an emergency situation, particularly in a fire, a lot can happen in just a few minutes. A fire in a non-compartmentalized structure with adequate oxygen supply and plenty of fuel sources to burn can double in size in just sixty short seconds. An average residential home can go from a small unnoticeable fire to fully involved structure fire, destroying everything in its path, in only five to ten minutes. With the potential for so much destruction in such a short amount of time, the response time for any responding fire department needs to be as quick and safe as possible. Such a response does not begin when the engine pulls away from the station but when the emergency dispatcher first takes the call from the concerned caller. Even by then the clock for fire suppression has already been running since the moment of fire ignition.

For fire emergencies, when a caller dials 911, the call is received by, or transferred to an Emergency Fire Dispatcher (EFD), who first verifies the address and phone number, then begins the call prioritization process by accessing the Fire Priority Dispatch System (FPDS™)^{1, 2, 3} using a logic-based software program, ProQA™. ProQA is an expert system which directs the calltaker in collecting vital information from the caller, including the nature of the incident and critical incident details, by completing several Case Entry Questions and Key Questions⁴. Once this critical information gathering is complete, ProQA's system logic recommends a dispatch determinant code, which is subsequently assigned to the case by the EFD. The case is then dispatched (i.e., assigned to a response crew or crews), and the EFD continues the call by asking additional Key Questions and then instructing the caller with incident-specific Post-Dispatch and Pre-Arrival Instructions⁵. The call prioritization time, therefore, is defined as the amount of time it takes for the calltaker to open ProQA, ask critical questions, and to confirm the dispatch (determinant) code for the case. This dispatch (determinant) code is used to assign the correct response units to the case, in the proper response mode – either emergency (with lights–and-siren), or non-emergency (no lights-and-siren use). Call prioritization time in a 911 center continues to be a topic of much discussion in public safety. There is no blanket approach to establishing a universal time standard for dispatch, unless defined at the level of a specific type of event (chief complaint) and a dispatch (determinant) code (situation). Additionally, because a widely accepted public safety standard defines total response time to a 911 event as beginning when the calltaker answers the phone, call prioritization time is viewed as a critical sub-component of total response time to an emergency scene. This places the 911 center in the awkward position of getting constant pressure from response agencies to shorten call prioritization time. However, the efficacy of the 911 calltaking process should first be evaluated.

In this study, we looked at the time required to reach call prioritization for different chief complaints and priority levels. This is the first study to look at call prioritization time in the FPDS. Results from this study will give an overview of the call prioritization time by various chief complaints and priority levels. This can be used to better understand, and characterize, call prioritization times for different protocols (incident types) and priority levels (Figure 1).

As described in detail in a previous study⁶, six priority levels (Figure 2) are used to define the relative urgency of the response, and several hundred determinant codes are used to describe the specific nature of the event providing a spectrum of response possibilities. Each local fire department can use these universal codes to craft its own response plan, including an agency-defined response to each determinant code, based on its individual organizational practices, policies, procedures, and geo-political realities.

OBJECTIVES

The primary objective in this study was to determine call prioritization time by Fire Priority Dispatch System Chief Complaint Protocols, and Priority Levels.

METHODS

Design and setting

This retrospective study involved nine emergency communication centers, accredited⁷ by the International Academies of Emergency Dispatch (IAED) as Emergency Fire Dispatch Centers of Excellence. The agencies described elsewhere4 included: Guilford Metro 911, Greensboro, NC, USA; Prince George's County Public Safety Communications, MD, USA (PGC); Mecklenburg E.M.S. Agency (MEDIC), Charlotte, NC, USA; Harford County Division of Emergency Operations, MD, USA; Sarasota County Public Safety Communication Center, FL, USA; Metro/Nashville Emergency Communication Center, TN, USA; Union County Emergency Communications, NC, USA; Kent County Department of Public Safety, DE, USA; Manatee County Emergency Communication Center, FL, USA.

Study population

The study sample included data collected between 2011 and 2013, using the FPDS®⁸ and also Accredited Centers of Excellence with the IAED⁹. The chief complaint (CC), priority level, determinant descriptors, and call prioritization time anonymous data were extracted from ProQA® (software version of FPDS)¹⁰.

Outcome measures

The primary endpoints in this study were the percentage of calls prioritized in 15, 30, 45, 60, 70, 80, 90, 120, and 180 seconds, and the median call prioritization time for each CC, and priority levels.

Data analysis

STATA software for Windows® (STATA Statistical Software: Release 13.1 ©2013, StataCorp, College Station, TX, USA) was used for data analysis. All calls in which the call prioritization time was less than 5 seconds or greater than 10 minutes were excluded from the analysis, because per the investigators' experiences, these time values were unrealistic in a dispatch environment. Cases with such extended times were likely due to dispatcher error from call duplication, or leaving open a case after it was cancelled and abandoned by the calltaker. The percentage of calls prioritized in 15, 30, 45, 60, 70, 80, 90, 120, and 180 seconds for each CC and priority level (ECHO, DELTA, CHARLIE, BRAVO, ALPHA, and OMEGA) was tabulated. The next analysis looked at the median (minimum-maximum) call prioritization time for each priority level categorizing by agency. Analysis of median (minimum-maximum) call prioritization time for each priority level was also performed categorizing by CC.

RESULTS

Over 200,000 cases (n=205,324) cases were studied (Figure 3). Of these cases, 191 were excluded due to prioritization time being 5 seconds or less (n=39) or more than 10 minutes (n=152). The remaining 205,133 (99.9%) were included in the study.

In reference to Table 1, these nine fire agencies prioritized all fire call types 63.5 % in 60 seconds or less, 88.8% in 90 seconds and 96.2% in 120 seconds or less and 99.2% in 180 seconds or less. Specifically, 88.0% of all the ECHO and 88.0% of all the OMEGA priority-level calls were prioritized in 60 seconds or less. However, 90% of calls were prioritized in each priority level in 90 seconds or less, except in the ALPHA and BRAVO priority levels (89.1% and 85.9%, respectively). Otherwise, nearly all calls 99.2% in each priority level were prioritized in 180 seconds or less.

Referencing Figure 2, those priority levels requiring urgency in response, ECHO and DELTA both received a call prioritization in 90 seconds or less over 90% of the time.

Generally, a sizeable number of FPDS protocols calls were prioritized in 45 seconds or less (75.0% for Protocol 56, 61.0% for Protocol 68, 58.0% for Protocol 63, 58.0% for Protocol 60, 50.0% for Protocol 72, and 50.0% for Protocol 53) (Table 2). However, approximately 80.0% of calls processed within Protocol 56 and Protocol 68 were prioritized in 60 seconds or less. Otherwise, calls processed within Protocol 56, Protocol 52, Protocol 68, Protocol 60, Protocol 53, Protocol 57, and Protocol 69, were prioritized in 90 seconds or less. Additionally, all calls processed within Protocol 63 were prioritized in 180 seconds or less. Finally, calls processed within each protocol, except in Protocol 62 (89.1%), were prioritized in 240 seconds or less.

In a previous study⁴ the top five call types were listed as Protocol 52 (alarms), Protocol 67 (Outside fires), Protocol 69 (Structure fire), Protocol 53 (citizen assist) and Protocol 55 (electrical hazards). The top 3, Protocol 52, 67, and 69 had all call types prioritized within 60 seconds approximately 65% of the time and 90% in 90 seconds or less. These top three Protocols comprised 70.8% of the total call volume represented in the study. (Table 2)

Overall, calls were prioritized in a median time of 52 seconds (18 seconds for ECHO, 46 seconds for DELTA, 54 seconds for CHARLIE, 55 seconds for BRAVO, 47 seconds for ALPHA, and 30 seconds for OMEGA Priority-level calls) (Table 3). Generally, there were observable inter-agency differences in call prioritization times for each priority level. PGC agency registered the shortest call prioritization time overall. However, Union County EMS agency produced the longest call prioritization times in each priority level, except in the ECHO priority level (31 seconds), where MEDIC agency registered the longest time (104 seconds). Additionally, Manatee County EMS agency had the shortest call prioritization times in all the main priority levels, except in ECHO and OMEGA priority levels.

In the previously referenced study⁴, it was identified that the MEDIC center covers approximately 500 square miles while Manatee and Union cover between 640 and 900 square miles. The discussion can be made for longer call processing times due to the area (metro versus urban) served by each center.

FPDS Protocol 56 had the shortest call prioritization time overall (35 seconds), followed by Protocol 68 (40 seconds) and Protocol 63 (41 seconds) (Table 4). All calls were prioritized in 90 seconds or less in all protocols, except in Protocol 59 (94 seconds) which had the longest call prioritization time.

The top 3 protocols with the shortest call prioritization time in each priority level were: ECHO priority level- Protocol 67 (15 seconds), Protocol 72 (16.5 seconds), and Protocol 69 (24 seconds); DELTA priority level- Protocol 60 (35 seconds), Protocol 67 (41 seconds), and Protocol 56 (42 seconds); CHARLIE priority level- Protocol 68 (40 seconds), Protocol 60 (43 seconds), and Protocol 53 (50 seconds); BRAVO priority level- Protocol 56 (34 seconds), Protocol 74 (36 seconds), and Protocol 63 (39 seconds); ALPHA priority level- Protocol 51 (15 seconds), Protocol 72 (34 seconds), and Protocol 56 (35 seconds); and OMEGA priority level calls being Protocol 52 (24 seconds), Protocol 56 (33 seconds), and Protocol 53 (40 seconds).

Finally, the longest call prioritization times in each priority level were: ECHO- Protocol 69 (24 seconds); DELTA- Protocol 65 (88 seconds); CHARLIE and BRAVO both had Protocol 51 (172 seconds and 128 seconds, respectively); ALPHA- Protocol 74 (98 seconds); and OMEGA with Protocol 75 (78 seconds).

TABLES AND GRAPHS

DISCUSSION

The findings of this study demonstrate that, although call prioritization times vary widely by Chief Complaint Protocol, the majority of calls are handled quickly. The majority (63.5%) of calls handled using the FPDS had call prioritization times of less than 60 seconds, while nearly all (99.2%) had call prioritization times of less than 180 seconds. Clearly, calls are being handled in a timely fashion, with sufficient information for appropriate dispatching occurring generally within one minute, and almost always within 3 minutes. High-priority calls are handled even faster, with much higher percentages of ECHO and DELTA calls being prioritized within 60 seconds.

Even the protocol with the longest median call prioritization time (Protocol 51: Aircraft Emergency) only had 18.3% of calls with call prioritization times over 180 seconds. Moreover, this number may be skewed, as Aircraft Emergency calls make up less than 0.2% of all calls. On the other hand, six protocols had more than 90% of calls prioritized within 90 seconds.

Median call prioritization times also varied by agency, with medians ranging from 85 seconds in the agency with the longest call prioritization times to 43 seconds in the agency with the shortest times. In all agencies except MEDIC, ECHO calls had by far the shortest call prioritization times, indicating that the highest-priority calls are being prioritized and dispatched very quickly across agencies properly using the system.

Most fire service and fire dispatching agencies measure their call or dispatch times, as well as their response times, against standards set by national agencies such as the National Fire Protection Agency (NFPA)¹¹ and the Insurance Standards Organization (ISO). These standards tend to apply exclusively—either by rule or in practice—to calls determined to be "emergencies," primarily Structure Fire incidents. Future research will more specifically address the ability of the FPDS to handle the various types of Structure Fire calls in accordance with these time standards. This study sets the baseline for call prioritization times appropriate to each varying type of fire response situation. In the future, time standards should reflect the times needed to do different things safely and correctly–not processes bent to meet one-size-fits-all time standards.

While 911 call centers continue to receive pressure from responding agencies to process calls faster, sooner or later there must be some discussion about how emergency vehicle collisions continue to be the second leading cause of firefighter death in the U.S. Without accurate and complete information obtained from a well-designed call prioritization process, we may continue to arbitrarily send all fire units "hot" to the scene at the "speed of death."

LIMITATIONS

While we had a relatively large sample size, there were several low-frequency chief complaints (e.g. 65, 62, 75, and 70) that did not yield an optimally high number of cases for statistical comparison. This was also true of priority level ECHO, in particular for one agency – MEDIC – where there were only 3 ECHO cases, which may explain the wide difference in median time for this agency's ECHOs. Finally, we were able to examine ProQA data only, not the entire case in the master dispatch computer (generally referred to as CAD). Hence we are not able to capture the entire dispatch time from phone pickup to 1st unit assignment – a time that includes address verification (at the front end of the call, before call prioritization time) and unit notification time (after call prioritization time).

CONCLUSION

Call prioritization times varied significantly by call type and Priority Level; however, in general, the highest-priority call types had lower median call prioritization times than lower-priority calls across agencies. Call prioritization time also varied by agency, although only two agencies had median overall call prioritization times of over 60 seconds. Future research will investigate the ability of the FPDS to handle specific call types—particularly Structure Fires—within time standards set by the NFPA and ISO, and create better time standards that better define the differences in call evaluation processes.

REFERENCES

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3. National Fire Protection Association. (2013). NFPA 1221 Standard for the Installation, Maintenance, and Use of Emergency Services Communications Systems (2013 Edition). Quincy, MA: Technical Committee on Public Emergency Service Communication.
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8. The International Academies of Emergency Dispatch. (2009). Fire Priority Dispatch System: v 5.0 (2009 release). Salt Lake City, UT: Priority Dispatch Corp.
9. The International Academies of Emergency Dispatch. (2014). Standards for Accreditation. Salt Lake City, UT.
10. The International Academies of Emergency Dispatch. (2009). Fire Priority Dispatch System: v 5.0 (2009 release). Salt Lake City, UT: Priority Dispatch Corp.
11. National Fire Protection Association. (2013). NFPA 1221 Standard for the Installation, Maintenance, and Use of Emergency Services Communications Systems (2013 Edition). Quincy, MA: Technical Committee on Public Emergency Service Communication.