Modifications to the Medical Priority Dispatch System in the age of COVID-19

The Medical Priority Dispatch System (MPDS), sometimes referred to as the Advanced Medical Priority Dispatch System (AMPDS) is a call taking system used to dispatch appropriate aid to medical emergencies including systematized caller interrogation and pre-arrival instructions. Priority Dispatch Corporation is licensed to design and publish MPDS and its various products, with research supported by the International Academy of Emergency Medical Dispatch (IAEMD). Priority Dispatch Corporation, in conjunction with the International Academies of Emergency Dispatch, have also produced similar systems for Police (Police Priority Dispatch System, PPDS) and Fire (Fire Priority Dispatch System, FPDS).

MPDS was developed by Jeff Clawson from 1976 to 1979 prior to his medical school training. Clawson designed a set of standardized protocols to triage patients via phone and reduce call processing time and create efficiencies in the emergency medical system (EMS) response. Protocols were first alphabetized by chief complaint that included key questions to be asked the call taker, give pre-arrival instructions to the reporting party, and to assign the proper resources to the request for EMS assistance.  

MPDS begins with a call-taker dispatcher asking the reporting party key questions. These questions allow the EMS dispatchers to categorize the call by chief complaint and to establish a determinant level ranging from “A” (minor) to “E” (immediately life-threatening) relating to the severity of the patient’s suspected condition. The phone information is used to accurately assign resources to the incident scene and the proper code of response i.e., red lights and siren. The MPDS also uses the determinant O which may be a referral to another service or other situation that may not actually require an ambulance response.

In 2020 the spread and concern of COVID-19 had caused a dramatic change in the procedures used by pre-hospital personnel in an effort to minimize risk following known, and unknown exposure to a patient with COVID-19. In an effort to minimize exposure on all EMS pre-hospital care patients many delivery systems are limiting the previously standard number of personnel arriving at the scene that physically interact with the patient. Further techniques including moving the patient from a confined space environment to the outdoors, and greater use of a higher level of PPE are practiced in an effort to minimize exposure. 

Each of these efforts, including additional questioning may benefit the hopeful outcome of reduced exposure. However, I believe that technology can provide additional benefit utilizing anonymized cell phone location data (“pings”) based on occupancy types that speak to the number of people per square foot, amount of linger time, and pathway crowding. This data could be used to better understand where people congregate and what methods could be used to leverage this data in an effort to minimize exposure to COVID-19.  

Information on person per square foot, time spent on location, activity during linger time i.e., sweating at a gym, seated at a church, could be used to more clearly identify potential location dangers of biological hazardous previously not well understood. This information will provide dividends in a healthy work environment, potentially higher morale, and overall healthy workforce, potentially saving resource dollars for other preventative needs.  

Locations and occupancies of potential “super-spreader” environments learned prior to arrival at the scene may reduce call to patient contact time as EMS response personnel can be fully and appropriately dressed in personal protective equipment (PPE) upon arrival at the scene. This data could lead to other modifications to EMS response not able to be understood today due to the lack of available data. 

Due to the heavy burden of workers’ compensation claims for federal, state and local government related to COVID-19, and the likelihood of additional biological challenges in the future, the potential benefit of leveraging anonymized cellular phone location data into the MPDS for responder safety and public health is highly valuable. 

My COVID-19 Antibody Testing Experience

The Novel Coronavirus disease has impacted the country at all levels of society, influencing and perhaps exacerbating beliefs about the value of science, importance of government, and the public’s appetite for risk. Because so much of everyday people’s understanding of the science of disease progression, and COVID-19 in particular, is not well understood by the population at large, each day new information is learned that shapes and/or fortifies earlier held feelings. And because of the availability of information that has not been vetted is written and published on an hourly basis, it may be difficult for the everyday American to carefully consider all of the important nuances in each article or news segment.

Like many others I was interested in learning if I had been exposed to COVID-19 earlier this year. I had been sick with a significant respiratory illness about the time of when the virus is reported to have first arrived in California. Because I regularly provide assistance to elderly relatives, I felt motivated to understand what my potential was for contracting and transmitting the disease. Early information indicated that the availability of testing was limited and that available COVID-19 tests would be reserved for those workers whose employment regularly interfaced with infected individuals.

With the passage of time I learned of a number of locations around Orange County, California that had COVID-19 testing capabilities. It was important that I establish baseline to learn if I had been exposed to COVID-19 to an extent that I had developed antibodies. During one of my limited trips to the supermarket I saw a sign that advertised “Instant COVID-19 antibody testing now available.” I made an appointment for the next day at 0800 when the emergency care facility opened for business that day.

When scheduling an appointment, I was pre-screened online by answering questions about why I wanted the COVID-19 test and if I believed I had been exposed. I was able to obtain the first appointment for the following morning, and upon arrival was surprised to find that I was the only customer at the facility. Because of the prominent sign advertising the availability of such a test, and the limited availability of testing, I had expected greater interest. I walked into the local emergency care facility, followed the written instructions pertaining to disease spread, and made contact with the medical receptionist. The process was efficient and involved a very limited amount of contact. I had worn an N95 face mask that I’ve had for months and the only other potential for transmission was the paper I handed to the receptionist. All of the billing questions and associated HIPPA questions were managed previously via online.

After about ten minutes, I was invited into a treatment room where I was met by a lab technician. The room looked exceptionally clean and the technician was professional. He looked for a site to draw blood and choose to use my left antecubital vein. Using and alcohol swab, proper site preparation and a small needle the technician drew a small sample of blood rapidly. When I asked about the anecdotal figures for those COVID-19 tests he noted that many of the tests were negative, specifically for Orange County. Without elaboration he seemed to indicate that the outcomes were different in other areas.


The testing that was performed was an immunoassay for suspected disease caused by the 2019 novel coronavirus, rapid SARS CoV 2 IgG + IgM Ab, QL IA serum or plasma. To the best of my understanding, this testing process attempts to determine if I have the antibodies following exposure to COVID-19. The test is designed to find antibodies for both near term, such as the last two weeks from the time of the blood draw (IgM), to long term (IgG). The sensitivity and specificity of the assay were not presented.

After about 15 minutes, I was given my result: my test was negative for COVID-19 antibodies, meaning that I was not exposed to the virus if this test proves accurate. The cost was $70.00.

This benefit of this exercise is that it forms a baseline for my exposure moving forward. Assuming I use the same cellular phone I would be able to track my movements and find when/where I am exposed in the future, if that happens. Other technological values that I do not fully understand may be used to follow my movements that could be used in the future to determine a when/where/who of a possible/suspected exposure. My experience illustrates the value of public testing and how this can be used to manage the risk regarding COVID-19 and the reopening timeline specific to state and local government.