Accuracy of a Priority Medical Dispatch System in Dispatching Cardiac Emergencies in a Suburban Community

Abstract

Over-triage of patients by emergency medical services (EMS) dispatch is thought to be an acceptable alternative to under-triage, which may delay how quickly life-saving care reaches a patient. Previous studies have looked at advanced life support (ALS) misutilization in urban- and county-based EMS systems and have attempted to analyze how dispatch methods either contribute to or alleviate this problem. The purpose of this study is to assess the relationship between dispatches of a cardiac nature in a Medical Priority Dispatch (MPD) system, and the actual clinical diagnosis as determined by an emergency department physician. Calls for emergency medical assistance in a suburban community outside of a major metropolitan area were surveyed over a three-month period. Medical Priority Dispatch protocols determined that 104 of these calls were cardiac-related. Of these emergency calls, 56 (53.8%) patients were transported to the local community hospital and treated by the emergency physician. A retrospective review of the medical records was conducted to determine whether the patient had a cardiac-related discharge diagnosis from the emergency department. Sixteen (28.6%) of the patients in this cohort were diagnosed with a cardiac-related condition upon discharge from the emergency department. Forty (71.4%) were diagnosed with a non-cardiac-related condition. The positive, predictive value of the dispatch protocol for the detection of an actual cardiac emergency in this EMS system was 28.6%. In this suburban community, the MPD system may over-triage emergency medical responses to cardiac emergencies. This can result in the only ALS (paramedic) unit in the community being unavailable in certain situations. Future studies should be conducted to determine what level (in any) of over-triage is appropriate in EMS systems using a MPD system.