The Ongoing Ambulance Response Time Debate

Feb 23rd, 2012 | By | Category: Response Times

(Article courtesy of JEMS and McCallion, EMT-B |

MedStar EMS Associate Director for Operations Matt Zavadsky dared to ask a provocative question in his presentation at the American Ambulance Association conference this past November, “Do Ambulance Response Times Really Matter?” He challenged the near-capacity audience to ask themselves if the speed with which EMS responders arrive on scene to every call makes a difference in patient outcomes.

The answer was, “Kinda.”

Obviously, there are certain high-acuity calls that require a timely response, i.e., cardiac arrest, shock, myocardial infarction, to name a few. But, Zavadsky says, these calls occur with less frequency than the majority of lower acuity calls that aren’t time sensitive. To treat every EMS call as though it’s a cardiac arrest puts EMS providers and the public in danger.

Zavadsky admits that responding lights and sirens to every call is the way EMS always has done it. Since the 1970s, arriving within eight minutes 90% of the time has been the gold standard for determining the quality of an EMS system. Response times are how EMS providers compete for contracts, and it’s how EMS leadership proves to the community that it’s providing quality service.

It’s even codified by the National Fire Protection Association. In fact, NFPA 1710 states that first responders and BLS units must arrive on scene within a four-minute timeframe 90% of the time for all incidents. The ALS crew that must respond within eight minutes. According the NFPA 1710, “This requirement is based on experience, expert consensus and science. Many studies note the role of time and the delivery of early defibrillation in patient survival due to heart attacks and cardiac arrest, which are the most time-critical, resource-intensive medical emergency events to which fire departments respond.”

The problem, says Zavadsky, is that cardiac arrests represent a very small percentage of the overall EMS responses. The Emergency Medical Services Outcomes Project (EMSOP) identified seven clinical conditions that account for 65% of all adult EMS transports and seven that account for 85% of all pediatric transports. Of these conditions, only cardiac arrest—the second least frequent of all the conditions—appears to require rapid EMS response.1 Although much of the assessment of an EMS system was developed based on how well the responders handle a cardiac arrest, the authors note that the vast majority of the calls don’t require the same time-sensitive response.

If the problem is getting trained personnel to a patient faster, then there is an easy fix: hire more paramedics. Zavadsky says that even if the economy allowed for such an expense, it’s unlikely that adding personnel would improve quality. Increasing the staff size would reduce an individual’s exposure to the type of decision-making and clinical skills that help to maintain proficiency. In critically unstable patients where time is a factor, paramedics must have the technical skill and analytical decision-making experience to improve the patient’s odds of surviving. “An inexperienced paramedic can do more harm than an EMT,” Zavadsky says.

He asserts an increasing body of scientific evidence exists to prove that response times do not, in fact, improve patient outcomes. What is needed is a critical review of localized data to help develop more refined response standards. If done properly, the result can be a decrease in system costs, fewer lights-and-sirens driving accidents and a more substantive measurement of the quality of an EMS system.

The MedStar example 
MedStar, serving the citizens of Ft. Worth, Texas, responds to 110,000 EMS calls annually. Zavadsky wondered if the value placed on speed was contributing to the number of ambulance crashes in the system each year, 74% of which occurred while driving with lights and sirens. He had been collecting data and analyzing responses for years to identify a better way to serve the public and “do no harm.” Then, during one cold, 48-hour period in February 2011, he was provided an unusual opportunity to conduct the perfect EMS study.

As sports fans poured into the Dallas-Ft. Worth area to see the Pittsburgh Steelers take on the Green Bay Packers in Super Bowl XLV, MedStar geared up for what was anticipated to be a busy week. However, no one could have predicted what happened next. Just days before the game, a severe winter storm blanketed the region in 13 inches of snow and ice. The weather was so severe that for a 48-hour period, MedStar, with the approval of its Medical Control Authority, the Emergency Physician’s Advisory Board suspended the use of lights and sirens. When the storm was over, Zavadsky compared cardiac arrest and chest pain responses during that 48-hour period to those of the previous week. “That kind of study is hard to do prospectively,” he says.

What he found was little difference between the patient outcomes between the two weeks. “Very few EMS calls required an immediate response,” he says. “The time critical responses were CPR/AED.” Even with chest pain calls, the problem was that the patients waited too long to call 9-1-1—not that the ambulance took too long to arrive.

The critical need, he determined, was in regards to public education. He calculated that by increasing response times from eight minutes to 15, MedStar could save approximately $1.5 million. By using that money to buy AEDs, do community CPR education and buy advertising to encourage the public to call 9-1-1 more quickly for chest pain and strokes, he argued, could have a more positive effect on patient outcome. “In some cases, the best response is before the call,” he says.

Public Expectations
Although some EMS professionals like Zavadsky suggest it’s time to re-examine the standard, the public may not be ready to give up response times without some retraining. Just ask Emergency Medical Services Authority (EMSA) officials. EMSA contracts with ambulance companies to provide EMS services for Oklahoma City, (Okla.) Tulsa, and surrounding suburbs.

Ward 2 Oklahoma City Councilman Ed Shadid, a vocal critic of EMSA’s spending practices, has expressed concern that the organization is trying to avoid complying with the 90% standard by using call exclusions for severe weather and times of high call volumes. Recently, that battle spilled over into the media.
According to EMSA records, in nearly one of every 10 emergency calls, paramedics were either late or the response time wasn’t counted due to an exclusion. “What’s been presented to the public is that there’s this 90% compliance,” Shadid was quoted in a local paper as saying. “Well, it’s 90% if you exclude calls.”
EMSA President and CEO Steve Williamson has pointed out that the exclusions were approved years ago by the cities involved. “We don’t want to jeopardize the safety of anyone, including the crew and the other citizens on the road. The exclusions are there to protect everyone,” he says. Regardless of the outcome, the resulting publicity reflects poorly on the entire system and affects how the public perceives its EMS responders.

What Needs to Change?

Although changing standards and the public’s perception is difficult, Zavadsky points out that if the American Heart Association can do it, so can EMS. He offers some suggestions to help move the argument forward, including the following:
• Classify calls and modify responses based on the classifications.
• Track AEDs that are purchased. Add that data to the dispatcher’s information and even call ‘owners’ of AEDs nearby to cardiac arrest calls and ask if they’re willing to bring the AED to the patient nearby.
• Put AEDs in police vehicles.
• Triage calls using Priority Dispatch. Find other options for non-emergent patients.
• Educate payers so that EMS services get paid for preventive community health home visits.
• Demonstrate how money saved can be used to help prevent emergency calls.
• Use customer surveys to measure quality and performance. Share that information.
• Make the first response piece more integral and accountable. If there is no first response layer, then add it.

According to Zavadsky, it’s possible to save valuable resources and improve patient outcomes. “The wave has already started,” he says. “The economics work in our favor.”

The key, he says, is to examine what really matters based on current science and common sense, measure it and share that information with the public. “There is no such thing as an inappropriate request for 9-1-1,” he says. “There is such a thing as an inappropriate response to that request.”

1. Sword RA, Cone DC. Emergency medical services advanced life support response times: Lots of heat, little light. Acad Emerg Med. 2002;9(4):288–29

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