You’ve Got Questions? Research Has the Answers

Emergency medical dispatch (EMD) practice has evolved exponentially in the last few decades.


Emergency medical dispatch (EMD) practice has evolved exponentially in the last few decades. It wasn’t long ago that emergency dispatchers were answering seven-digit phone lines, recording information manually and tracking calls with punch cards. Prearrival instructions for medical callers in need were nearly nonexistent and most dispatchers were strictly clerical; they simply obtained a location and dispatched a resource. Today, sophisticated computers track, record and manage everything from the time the call is received to the time the responder(s) has cleared the call and, in some cases, patient records are added to the dispatch database. Prearrival instructions are now in widespread use and are considered a current standard of care. However, while advances in technology can explain the use of computer-aided dispatch systems, the advancement of the clinical aspect of EMD (prearrival instructions and priority dispatch practice) is less clear. This is because clinical research in this field is far less evolved as compared with traditional medicine. Even given the popularity of EMD today, with both modern communication centers and the general public, EMD is relatively unproven in the eyes of research-oriented clinicians. The lack of EMD research is likely the result of several unique factors.

Traditionally, clinicians and scholars, primarily physicians, have conducted clinical research and in a profession that has only recently been viewed as clinical, there has been little physician involvement. However, this fact is changing rapidly as medical directors today are overseeing EMS systems full-time. Emergency physician groups are advocating EMD research as the public has grown to expect prearrival instructions that are delivered safely and responsibly.

Another factor that has thwarted EMD research is the fact that established dispatch protocols have different goals than the typical on-scene clinician. Protocols attempt to provide for prearrival safety, designate an efficient and effective response allocation and mode, provide prearrival instructions and inform responders rather than provide a specific diagnosis. The misconception that EMD protocols are diagnostic has prompted attempts to compare paramedic impressions or hospital diagnosis to EMD protocol codes; because these outcomes are so vastly different, this sort of research is akin to comparing apples to oranges.

Some studies have attempted to compare patient acuity, as evaluated by clinicians or a focus group using a standardized acuity scale, to dispatch protocol codes in an attempt to validate the dispatch protocols. While the acuity scales used in these studies generally relate to patient acuity, their relationship to dispatch protocols is subjective. In other words, people, generally a focus group, must assign a range of dispatch protocol codes to the established acuity scale. This subjective assignment introduces variance that, while perhaps acceptable depending on application, restricts the validity of the study.

Variance is an important consideration. Good research is dependent upon controls that ensure the studies’ conclusions are accurate and not falsely based on an uncontrolled variable. With patients and callers out of sight, and with considerable time delays between caller interrogation and responder arrival, there are enough variables to discourage even the most determined researcher.

Perhaps the most easily controlled but often neglected variable in dispatch research is protocol compliance. Unfortunately, the vast majority of studies involving dispatch protocol have not reported compliance rates. Specifically, if compliance to the dispatch protocol is not absolute, unacceptable variance is introduced that will certainly affect the outcome of the study. If the protocol is not followed exactly, then the outcomes may be nothing more than the product of an individual’s decisions, rather than the protocol itself.

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