The Evidence

Bailey, E.D. & Sweeney, T. (2003). Considerations in establishing emergency medical services response time goals. Prehospital Emergency Care, 7(3), 397-399.

“Basic emergency medical technicians (EMT) typically have the ability and capability to save lives depending on local system protocols and what the state allows in the EMT scope of practice. For the medical case, airway support and protection, CPR, automatic defibrillation, and epinephrine administration using an autoinjector may all fall within the basic life support scope of practice. These time-sensitive interventions matter and can save lives. For trauma, airway support and ventilation, bleeding control, and immobilization may all be performed prior to arrival of ALS care and ambulance transportation.”

“Except for cardiac arrest, there is little or no scientific evidence suggesting a causal relationship between response interval and improved patient outcomes. There is little evidence linking improved response intervals to improved survival in critical trauma, and there is no literature suggesting that rapid response intervals improve outcome for noncritical patients.”


Baker, M. (February 2014). Rightsizing. Journal of Emergency Medical Services. 60-63.

“The [National Commission of Fire Prevention and Control] calls the practice of responding to medical calls with full-size apparatus, ‘an expensive and inappropriate use of equipment’.”

“One deployment concept that appears to be regaining significant traction as an option for the fire service to meet both a decrease in budget and an increase in the demand for organizational efficiency is the transition from full-size fire apparatus to smaller rapid-response vehicles (RRVs).”


Blackwell, T.H. (July 2011). EMS response time standards. In J.M. Goodloe and S.H. Thomas (Eds.), Emergency medical services evidence-based system design white paper for EMSA.

“Decreasing EMS system response times is laudable on any first contemplation, but careful analysis yields realizations that the costs are great, the benefits suspect, and the perceptions substantial.”


Blackwell, T.H., et al. (2009). Lack of association between prehospital response times and patient outcomes. Prehospital Emergency Care, 13(4), 444-450.

“The results of this study showed no evidence of increased mortality or increased requirement for critical procedures during transport for Priority 1 patients in association with an ALS response time exceeding 10:59 minutes.”


Blackwell, T.H., & Kaufman, J.S. (2002). Response time effectiveness: comparison of response time and survival in an urban emergency medical services system. Academic Emergency Medicine, 9(4), 288-295.

“Comparing actual and expected survival rates based on arbitrarily assigned response times, there was no statistically significant difference for times between 5 and 10 minutes, and no evidence to suggest any dose–response trend in this region of the data.”

“There was some apparent evidence for a survival benefit associated only with response times less than 5 minutes.”


Boland, L., et al. (2015). Advanced clinical interventions performed by emergency medical responder firefighters prior to ambulance arrival. Prehospital Emergency Care, 19(1), 96-102.

“Firefighters performed at least one of the six advanced EMR training interventions studied in 7.6% of the patients they were able to reach before paramedics, but the impact of these interventions on patient outcomes remains unknown.”

“As contemporary EMS system planners strive to maximize the efficiency and benefit of response resources, the medical role of [firefighters] needs to be examined more systematically, particularly in locales that are robustly supported with timely paramedic care.”


Davis, R. (March 1, 2005). Paramedics not always the saviors of cardiac-arrest patients. USA Today.

“Cities with the highest survival rates, the data suggest, train firefighters and citizens to respond first with defibrillators and CPR, sending in a smaller, closely supervised corps of paramedics minutes later to give advanced care.”

“Seattle, Boston and Tulsa represent cities with fewer paramedics. They believe that a paramedic who rides a fire engine to every call doesn’t get enough practice providing skilled care because so few calls are real medical emergencies.”


Eckstein, M. (July 2011). Basic and advanced life support considerations (BLS vs ALS – What does it mean for system design?). In J.M. Goodloe and S.H. Thomas (Eds.), Emergency medical services evidence-based system design white paper for EMSA.

“When more paramedics are added to a system, the number of critical procedures and critical patients per paramedic declines unless population and patient requests increase in respective manner. This is rarely the result. Instead, a multitude of paramedics now arrive on scene, and the result can be dilution of skills.”

“Having exclusively ALS resources respond to and transport patients who usually only require BLS treatment is inefficient, costly and will likely lead to worse outcomes due to dilution of critical skills and burnout.”


Myers, J.B., et al. (2008). Evidence-based performance measures for emergency medical services systems: A model for expanded EMS benchmarking. Prehospital Emergency Care, 12(2), 141-151.

“As more paramedics are added to a particular system, however, the frequency with which each individual paramedic has the opportunity to assess and manage critically ill or injured patients in the primary or “lead” paramedic role may decrease.”

“Pragmatically, considering that ALS cases constitute a small minority of all EMS 9-1-1 responses, adding more paramedics into the system may actually reduce an individual paramedic’s exposure to critical decision-making and clinical skill competencies.”


Pons, P.T., et al. (2005). Paramedic response time: does it affect patient survival? Academic Emergency Medicine, 12(7), 594-600.

“When response time was modeled as a continuous variable while controlling for scene time, transport time, patient age and gender, and level of illness severity, there was no effect on patient survival to hospital discharge.”

“There does appear to be a survival advantage for patients in instances where paramedics respond within 4 minutes. It is unclear, however, which patients besides those experiencing cardiac arrest benefit from such a brief response time, and this was not specifically evaluated in this study.”


Pons, P.T., & Markovchick, V.J. (2002). Eight minutes or less: does the ambulance response time guideline impact trauma patient outcome? The Journal of Emergency Medicine, 23(1), 43-48.

“This study demonstrates that ambulance response time does not have any effect on survival for patients who sustain significant trauma requiring admission to a trauma center.”


Pouliot, R.C. (2010). Failed prehospital tracheal intubation: A matter of skill dilution? [Letter to the editor]. Anesthesia & Analgesia, 110(5), 1507-1508.

“Published data suggest that systems using fewer paramedics per population unit create greater opportunity for practice of advanced life support skills and demonstrate greater proficiency with tracheal intubation. In addition to skill success, such targeted response strategies have been shown to increase survival in out-of-hospital cardiac arrest and traumatic brain injury.”

“Limiting the number of paramedics based on population and effectively targeting their response may be an efficient way to prevent skill dilution, increasing proficiency with tracheal intubation.”


Sanghavi, P., et al. (2015). Outcomes after out-of-hospital cardiac arrest treated by basic vs advanced life support. JAMA Internal Medicine, 175(2), 196-204.

“Our results suggest that the use of ALS is associated with higher mortality than the use of BLS in patients with cardiac arrest.”

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