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Sensitivity and Specificity of Emergency Medical Dispatching Protocols in the United States

Apr 04, 2022|AEDR 2022 Vol. 10 Issue 1|Original Research
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Objective: Emergency medical services require the accuracy of priority dispatching to optimize the match between patients' medical needs, prehospital resources, and maintaining patient safety. When ambulances are traveling with Lights/Sirens rather than with other vehicles' flow and speed on the road, they place themselves and the public at a higher risk. From 1992-2011, 58% of all injuries and fatalities in ambulances occurred when the ambulance was traveling with Lights/Sirens. EMS physician(s) are responsible for all aspects of the EMS system, including EMD protocols. This research aims to evaluate the sensitivity and specificity of EMD protocols in the United States.

Methods: Data were collected from ESO. The data were analyzed to determine multiple variables' sensitivity and specificity when the ambulance was dispatched with Lights/Sirens compared to no Lights/Sirens. 

Results: The study results showed that 87% of all 911 calls were dispatched with an ambulance using their Lights/Sirens when traveling to the patient, and 86% of the patients transported were transported with no Lights/Sirens. When comparing the use of Lights/Sirens upon dispatch to their use during transport, EMDs had a positive predictive value of 15.6% and a negative predictive value of 97.9%. The area under the receiver operating characteristic curve was 0.76. Regarding the vital signs data, the Lights/Sirens transport results suggest that patients are generally sicker than those without Lights/Sirens transports.

Conclusions: With a negative predictive value of 97.9%, better dispatching of ambulances needs to be implemented to help reduce the risk of death and injuries to providers and the public. EMS physicians should evaluate and better determine the level of response by all responders in their area. In addition, a secondary-triaging system could help reduce the over-triage rate suggested by the results and previous studies. Although, with a risk-averse mindset in the medical field, there is a fear of not responding fast enough. Better physician oversight and additional research with secondary-triaging systems might lead to more appropriate responses. 



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