Original Article

Does Ambulance Response Time Influence Patient Condition among Patients with Specific Medical and Trauma Emergencies?

Authors: Steven Weiss M,D, Lynne Fullerton, PhD, Scott Oglesbee, BA, Brynn Duerden, MD, Phillip Froman, MD


Objectives: The relation between patient outcome and ambulance response times is unknown. We sought to measure the influence of shorter response times on patient outcomes. The objective of the study was to determine whether ambulance response time makes a difference in the outcomes of emergency medical services (EMS) patients with specific traumatic and medical emergencies.

Methods: This study was conducted in a metropolitan EMS system serving a population of 800,000, including urban and rural areas. Cases were included if the private EMS service was the first medical provider on scene, the case was priority 1, and the patients were 13 years old and older. A 14-month time period was used for the data evaluation. Four diagnoses were examined: motor vehicle crash injuries, penetrating trauma, difficulty breathing, and chest pain complaints. Data collected included ambulance response times, initial vital signs, and the number of vital signs out of range. Cases seen at the single major trauma center were selected for evaluation of hospital outcome. Correlation coefficients were used to evaluate interactions between independent and outcome variables.

Results: Of the 2164 cases we reviewed, the EMS service responded significantly faster to trauma complaints at 4.5 minutes (n = 254) than medical complaints at 5.9 minutes (n = 1910). In the trauma center sample of 559 cases, response time was not related to hospital days (P = 0.5), admissions (P = 0.7), intensive care unit admissions (P = 0.4), or deaths (P= 0.3).

Conclusions: This study showed that in cases seen at a major trauma center, longer response times were not associated with worse outcomes for the diagnostic groups tested.

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