Passing ‘Fast’ for ‘Appropriate’ Responses

During the height of the COVID pandemic, shortages led to many operational challenges that required creative solutions. One of the more challenging issues that has become as endemic as the disease itself is the recruitment and retention of EMS professionals. This shortage has disproportionally impacted paramedics, as evidenced in the NAEMT survey results published in May of 2022. The ripple effect of the workforce reductions that has changed the certification balance favoring basic credentials has led to some logistical changes in priorities. The most recent NAEMT survey results, published last month, show services are taking longer to respond to requests, considering alternatives to serve low acuity calls, and changing the provider mix that services patients.

As more agencies move from exclusive ALS capabilities to tiered responses, there must also be a growing concern with ensuring the most appropriate resources are responding to each call. The idea of thoughtful intentionality in the assignment of units helps to improve the chances that the right resource will be available to the next future request for service. I like to describe the logical shift in thinking as moving from “the right response times on every call” to “the right call for responses every time.” This may be a subtle but highly significant change in attitude regarding the best, or most “appropriate,” response assignments to each request rather than routinely sending the closest unit. Managing these resources well may additionally involve adjustments to the expectations of your community.

Depending on the priority of a call, it may be that the closest resource is logically passed over for a more appropriately matched capability responding to that call from a greater distance. While the 90th percentile response times may increase for certain lower acuity calls, this selective assignment process allows advanced capabilities to be preserved for potentially higher acuity needs. But it is seldom really as simple as it sounds. How much further can that preferred response be before its preference is overtaken by the need to simply respond promptly?

The reality of these critical decisions means the process becomes far more complex and dangerously slower. The more conditions that must be understood and compared extend the time for each dispatch without automated assistance. By planning and codifying dynamic selection criteria, the extra delay can be eliminated which means making far better decisions in no more time than traditional fastest responses. These guided decisions can also be made uniform across positions and shifts to achieve corporate objectives that prioritize clinical outcomes based on acuity in addition to broad operational objectives that consider the condition of crews.

A typical Charlie priority call, for instance, might prefer to have a paramedic respond timely. That ideal response might be within, say, 15 minutes. With expected delays beyond that time limit, it may be acceptable to dispatch a BLS unit to begin care while still allowing the ALS resource to join the response from a longer distance. However, the practicality of that rigid rule may send a basic unit on a 14-minute response when the nearest advanced unit is only 16 minutes away. That implementation of a simple preference for immediate care has practical limitations because it committed two units with little time for the first to even complete an assessment before requiring a hand-off of care. Is the additional drop in service level worth the brief time savings in this example?

Response rules should be focused on improving both the speed and quality of outcome without artificially taxing the system. In this case, the lower-level capability may only be desired if it will be more than at least 3 minutes faster than the closest ALS unit regardless of its distance to travel. Without more time for basic intervention on scene, the multiple assignments are only tying up more response units without actually improving care.

A Delta priority request may also need a speedy paramedic response and a basic unit alone for too long may not be an adequate alternative. However, matching a paramedic QRV, or another supervisor, with that nearest BLS resource provided that it can be completed in 5 minutes less time than the closest ALS ambulance could be an acceptable solution.

While the time-sensitive examples above show better potential for care, there are also system benefits with appropriate responses on the lower acuity side of the scale. A Bravo request could be most efficiently served in a BLS capacity with longer response times before it would be deemed late. Yet if the preferred units are just not available by the time a limit approaches, an ALS resource could be dispatched to keep your response statistics within acceptable limits.

The impact of posting schemes on response capabilities cannot be overstated. There simply is no substitute to having the right resources located closer to their next most likely call. But the post priority can also be useful in assigning appropriate responses at the low-end of the acuity scale. A hospital discharge, or typical interfacility transfer, will not benefit from sending a fastest unit. The posts nearer the hospitals tend, in general, to be busier locations. Using one of those units not only increases the chances of keeping a crew within the vortex of handling patients, but it also exposes a potential lapse in coverage until another unit can be moved from a less active post. If the assignment is given initially to the unit filling the least critical post, there is no immediate coverage loss and no additional post moves required. Assigning an appropriate unit for this call can actually reduce the effective activity, or UHU, of other resources.

Appropriate dispatch is becoming a necessity to balance workloads and provide the best care possible to our patients given current trends. It comes, however, at a cost to the complexity of decisions demanded of telecommunicators unless they are given tools to help manage the art and science of dispatching. But to be effective, we must use appropriate automation tools for the best results.

Quick thoughts from TriCON 2012

The theme for the TriCON 2012 conference in San Diego was “Breaking Barriers” and that is certainly what TriTech presented during the plenary yesterday regarding their next generation dispatch system and their consolidation of recent business acquisitions. The crowd was clearly the biggest ever for this conference at about 430 users. A show of hands made it clear that the majority of these attendees were VisionAIR clients with VisiCAD users a clear runner up in representation. However the future direction for TriTech was definitely a merger of several systems, both internal and external to the business, as explained during the opening session called “TriTech Update: One Company.” It was explained that the products would be simplified into a family under the names of “Inform”, “Perform”, and “Respond.” While the names were beginning to be used this week, it was admitted that it will take some time for the actual rebranding to be complete. Attendees at this conference would almost exclusively fall under the “Inform” name reserved for the larger volume clients using applications now called VisiCAD or VisionAIR. Smaller dispatch clients would be in the “Perform” category and “Respond” will include EMS and billing systems.

This type of re-categorization even extended into a restructuring of the organization around functional “centers of excellence” that would be geographically recognized. San Diego, for instance, will become the center including GIS integration and Castle Hayne will host law enforcement functions. Darrin Reilly, the new COO, explained the need to reorganize the company allowing them to take advantage of future trends given that fact that IT evolution will be greater in the next 12-60 months than ever before.

The apparent effect of this reorganization was already evident in the product demonstrations that began with a significant ‘rethinking’ of the integration of CAD and E9-1-1. An illustration that showed how CAD could work differently – and even be implemented incrementally – contained significant integration with Google technology. Integrating search powered by Google into the call-taking screen significantly enhances search as well as map display tools and ultimately dispatcher knowledge.

Integrating the phone system with the CAD enables new features such as automatic call-back dialing by clicking on the phone number displayed on the dispatcher’s screen. Mapping of the incoming calls provides a visual “spatial awareness” that can provide advanced prioritization as a step toward Next Generation 911. In the case where several incoming calls are clustered around a documented incident while others appear at a great distance, it can be assumed that certain calls may be redundant reports while others could be regarding new incidents. The demonstration also showed the possibility of integrating live report calls directly into the TriTech Mobile application for immediate access by first responders.

There was more talk about the benefits of spatial technology integration yesterday with users asking for updates to the TriTech applications in order to support current ArcGIS 10 technology from Esri, but more focus seemed to be on Google-based mapping from the TriTech presenters rather further leveraging GIS technology beyond simple geographic display.

Then this morning Brian Fontes from NENA discussed the future of NG911 answering the questions “What is it and where are we going?” Following that presentation were several other break-out sessions, many of which focused on law enforcement applications which appeared to me to be somewhat disproportionally represented given the audience.

Now off to TriFest in Old Town San Diego tonight!

Measured Response to Response Measures

In conversations lately I have been hearing more diverging opinions on measuring EMS response ranging all the way from it being a definitive criteria to saying  it shouldn’t be considered at all. A recorded example of such a discussion is a recent blogtalkradio episode by “EMS Office Hours”.  While certainly appearing to be diametrically opposing opinions on the surface, I believe that there is more in common between these positions than actual difference.  Everyone agrees that responder safety is paramount and also that speeding ambulances endanger not only the medics, but the public as well.  However, to assume that the “observer effect” of simply measuring the response time is a casual factor in promoting unsafe practice is not always justified.

To clarify the commonality, it is worthwhile to first discuss the measurement itself.  When does the clock measuring response performance actually start and when does it stop?  The answer likely depends on your perspective.  As a patient in cardiac or pulmonary distress, rescuer performance is rightfully measured from symptomatic onset to relief.  For a dispatcher, it can be from the point of answering the call for service to the paramedic greeting the patient.  For the responding agency, it can be from the initial dispatch time to the time of “wheels on the curb” at the scene.

In reality, it doesn’t matter what you choose measure, the point is ultimately how efficiently can service safely be rendered to achieve a positive clinical outcome.  Opponents to time response measures will say that the focus is brought to the wrong objective.  That only considering the arrival time leads to the foolish notion that arriving within a compliant time when the patient ends up dying is somehow better than being late while the patient ultimately survives.  But carrying the discussion to that ultimate extreme of logic is not beneficial to the underlying argument.  There is little disagreement that many EMS calls do not require excessive speed, but the outcome of certain calls clearly depend on early treatment and the difference between those cases is not necessarily clear at the time of dispatch.  So arriving in a short time after being dispatched can aid in achieving a positive outcome clinically.

What everyone wants to avoid is the danger of excessive speed in arriving to calls without any delay in beginning treatment for the patient.  The answer is in pre-positioning vehicles closer to the call before it is received.  That leads back to my last post on forecasting calls for dynamic system status management.  With proper forecasting and posting of ambulances, you can assure the fast, safe arrival of resources to begin treatment.  So again, no matter how you measure it, the positive relief of ailment is the outcome we all look to achieve.  To compare efficiency you need some objective measure of performance.  The responsive initiation of treatment leading to a healthy outcome is such a measure but is just not the only factor to be used in describing performance.

Let me know how you see it.

Dynamic System Status Management

System Status Management (SSM) is the fluid deployment of ambulances based on the hour-of-the-day and day-of-the-week in order to match supply, defined as Unit Hours of Utilization (UHU), with expected demand, expressed as calls for service, in the attempt to provide faster response by locating ambulances at “posts” nearer their next calls.  While the practice is still not unanimously embraced by all services, it has a sound foundation both in the research literature dating back to the 1980’s as well as in practice today.  Experience has shown that ambulance response times can be dramatically decreased using this type of dynamic deployment, but it is also recognized that it is possible to reduce performance when these techniques are not applied properly.  The direction of the results of a system implementation are typically influenced by the system design, competence of the managers creating the plan, and commitment of the workforce in implementing it.  Therefore the best practice is a simple and straightforward implementation that will show positive results quickly.  This methodology ensures a positive return on investment along with garnering the necessary buy-in from staff to make the project a success.

In his article, “System Status Management – The Fact is, It’s Everywhere“,  published in the Journal of EMS (JEMS) magazine back in 1989, Jack Stout explained the concept of SSM and tried to dispel certain myths.  Based on foreseen Geographic Information System (GIS) technology and even general computing capabilities of that time, it was quite logical to assume in his Myth #2 that “no matter how thoroughly the response zone concept is fine-tuned in practice, it cannot be made to cope effectively with the dynamic realties of the EMS environment.”  But systems implemented today around the US are capable of calculating dynamic response zones in a small fraction of a second while even being based on time-aware historic driving patterns making a truly dynamic system status management process a reality.  A practical and proven example of a dynamically functioning system status management application is the Mobile Area Vehicle Routing and Location Information System, or simply MARVLIS.

The following Slideshare presentation does an excellent job of telling the story of why and how the system works:

High Performance EMS is MARVLIS

View more presentations from hp_ems

Addressing Geovalidation

The most fundamental aspect of an E-911 emergency dispatch center is to be able to locate a call for service and communicate that location to the closest appropriate vehicle to be dispatched.  In nearly every case, that location description is eventually an address.  The back-end process starts when a call is placed to 9-1-1 from a traditional wired land-line and its Automatic Number Identification (ANI) is compared to phone company records to find the Automatic Location Identification (ALI) address which is then compared to the Master Street Address Guide (MSAG) database to determine which Public Safety Answering Point (PSAP) or “call center” will receive that call.  It is the dispatcher at the PSAP who will determine the required resources and ultimately dispatch the requested assistance.  For cellular phones, VOIP, or telematics, the process is a little more complex to return a current latitude/longitude coordinate rather than a pre-determined address.  In those cases, the PSAP will interpret the caller position to a nearest address using Geographic Information System (GIS) technology.  The process of turning an address into a latitude/longitude value is called “geocoding” by GIS people and “geovalidation” by EMS staff.  The inverse of that process, finding the address of a specified point, is preceded with the term “reverse” by either crowd.  So, regardless of how the location information is presented to the PSAP, the closest resources can be found by comparing points and, in return, an understandable location descriptor can be provided for any point – at least in theory.

The ability of the GIS to translate addresses into coordinates in order to determine the closest responder (or the reverse process of turning an incident location into an address to communicate that location) is based on the quality of the geographic street database and its attributes.   Some US counties create their own data, but many others use street data from national level providers including the US Census Bureau who provides free TIGER/Line files and commercial sources such as TomTom (formerly TeleAtlas) or NAVTEQ as a foundation.

The accuracy of the street centerline shape for any segment of road allows a coordinate to be located precisely along the correct street and the address range attributes allow a position to be accurately described with an address.  So to make this all work, the centerline shape of your data must reflect the actual shape of the road on the ground and be segmented (typically broken at street intersections) to allow address ranges to be defined over limited distances.  These attributes typically include left-from-address, left-to-address, right-from-address, right-to-address (relative to the increasing direction of the numbers), prefix or direction, street name, street type, and suffix or direction for each segment of street at a minimum.  This all sounds very easy, but the real world always gets more complicated than our simple schemes.

According to David Hunt, GIS Analyst and 911 Coordinator for Wake County in North Carolina, “the whole country has been actively converting [rural] route and box numbers to addresses over the last 25 years,” but the process has not always been consistent.  The distance between addresses was not always uniform before the general availability of GIS for addressing.  Good centerlines make the address assignment process much easier for new subdivisions using GIS, but reflecting current addresses in an automated fashion is still not always straightforward.

Consider the following example from an older part of town where the house numbers are sequential based on structures rather than an increment distance as is more common in modern neighborhoods.  The house in the center is 502 and the structure next door to the east is 504 followed by 506 at the end of the street.  The structure on the west side of the middle house is 402 since there used to be an alley (but which is now closed) between those properties.  The next structure further west is on a corner and numbered 400.

So technically this street segment includes the 400 AND 500 blocks of this street.  The “right-from-address” would clearly be 400, but what is the “right-to-address”? Since the next block starts at 600, it could logically be either 506 or 598.  What is the difference?  Well, the greater ending value allows for more possible matches of any addresses searched but also provides approximation of non-existent addresses in a reverse-geocoding process. If a point query returned an address communicated as “410 S Washington St”?  Would it be located just 5% along the length of this street putting it at the actual structure numbered 400 or is there something between the structures at 402 and 502 that we need rescuers to find?   The smaller ending value limits some of the possible addresses and would not allow a possible match for a search on a non-existent house number like 510.  However, unless the segment is broken between 402 and 502, as it once was in reality, it would return an estimated coordinate for a query on a fictitious 404 instead of suggesting an entry error.

Another way around the problem is point-based addressing with GIS as managed in Sumter County, SC which limits queries to only actual house numbers in the geovalidation process.  Instead of applying the range attributes to the graphic representations of the centerlines, points are entered for each structure.  This also simplifies the problem with addressing mobile homes which need to change address as the actual dwelling is relocated.  “Making the digital address points more easily accessible helps create less issues,” says Emily Banar, GIS Analyst for Sumter County in charge of addressing.

Individual geocoding services provided through the GIS, named “locator services” by Esri, can be combined as “composite locator services”.  A composite geocoding search  is one that uses more than one single locator in order to attempt to match all possible addresses against more than one geographic dataset.  Combining search methods can provide more reliable geovalidation for your High Performance EMS by using a point range before a street range.

TheAddresser™ is an application built for both ArcGIS Desktop and ArcGIS Server by BCS as a complete address management system for both street ranging and single point addressing.  Business rules are built-in to the application logic to manage overlapping ranges, out-of-range addresses, as well as others to ensure that street centerline ranging and single point addresses stay in sync with each other and address accuracy is maintained.  This system also includes street name management and reporting of existing address errors.  Other tools of this system aid in the ease of editing street centerlines and address points to make sure that your GIS-based geovalidation process works as it should.

HP-EMS Profile: MEDIC

Each month we will feature a profile of another High Performance EMS to show the variation in these services and inspire others to reach beyond just the basic services to provide advanced pre-hospital care with a focus on high economic efficiency.

In 1996, the Mecklenburg EMS agency was one of the slowest in the US with an average call response time of about 16 minutes.  Today, calls average around 7 minutes.  That incredible transformation began when two competing hospital services joined together to create MEDIC which now contracts to serve the county of 540 square miles with a fixed population of 850,000 that swells to a routine daytime total of around 1 million people.

MEDIC Emergency Dispatch Center

Barry Bagwell, Deputy Director of Operations, is proud to state that MEDIC has been compliant regarding performance every month since 1998.  “While there is no ‘silver bullet’, all of the pieces must work together,” says Barry, “it requires technology plus the people to run it.”  But a truly High Performance EMS must not be tempted to over-utilize response times as the only measure of success. The original focus for system improvement was on routing, but the partnership with Bradshaw Consulting Services has led to many operational enhancements including successful demand prediction and dynamic System Status Management planning.  “Dispatch posting is a ‘chess game’,” Barry admits and real efficiency comes by balancing moves between the 60-65 posts to meet service demand with reducing fuel costs and minimizing disruption of ambulance crews.  With a holistic view of clinical outcomes, MEDIC has achieved a 33-minute turn-around time from hospital to availability and 82 minutes from a call to having a Code Stemi patient on an operating table with the artery open.  MEDIC also provides bicycle paramedics, ATV, and buses for special events to meet the needs of their community.

The dispatch center has used ProQA Dispatch Software protocols in both EMS and Fire since 1993 to assist dispatchers in quickly determining the appropriate determinant code.  Voice communication with vehicles is maintained with a Motorola 800 MHz shared backbone radio system with priority.  Non-emergency numbers are provided only to hospitals with the public being triaged through the 911 system.

While recognized as a High-Performance EMS already, MEDIC does not intend to rest where they are now but constantly looks toward additional improvements.