2.1 Time to First Medical Contact

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Description of Indicator

Relationship to Quality Medical care should be timely
Type of Indicator Prehospital process, System level
Proposed Data Sources Emergency Medical Services (EMS) Records, Emergency Department (ED) Record
Definition Time from onset of injury to first medical contact*
Numerator Time of first medical contact* with injured patient age 18 years and older – time of injury‡†
Denominator Not applicable
Benchmark Not specified at present
Risk Adjustmentβ Geographic area (urban, suburban, rural), initial GCS, ISS, mecha-nism of injury, type of injuries

* First medical contact = time at which the injured patient had first contact with a medical provider. In the field this may include a medical first responder, paramedic or other emergency medical service provider, depending on the jurisdiction. For patients presenting directly to a healthcare facility (e.g. Hospital ED) first medical contact will be the time of arrival at the healthcare facility.
‡ Time of injury may not be precisely known, but is likely to be accurately estimated by initial medical service providers. We believe that using time of injury as a starting point for prehospital time based measures is conceptually attractive from both physiological and quality improvement perspectives as it represents the onset of tissue injury. It is analogous to using time of symptom onset in patients with stroke or myocardial infarction.
† Time to first medical contact will be reported as an interval measure (mean or median) with a measure of variation (standard deviation or interquartile range).


This indicator is intended to reflect community system response, access to 911, dispatch of resources and actual time of first medical contact. The indicator consists of an amalgamation of four separate measures evaluated by the Quality Indicators in Trauma Care Consensus Panel; Scene Time, Prehospital Time, Time of Decision to Transport Patient to Trauma Center and Patients Transferred to Another Health Facility after Spending >6h at the Initial Hospital.

Panel Review
Panelists agreed that time is an important factor in patient care and expressed that measurement of multiple time metrics is possible, each with different implications. With limited evidence for the clinical importance of specific time thresholds, it was suggested that it may be simplest to report time12. In addition, panelists emphasized the importance of reporting and/or adjusting for geographic area and mechanism and type of injuries, and specifically the value of restricting the use of this indicator for severely injured patients.
Panelists discussed when time measurement should begin and outlined that time of EMS dispatch could likely be accurately recorded. Conversely, using time (or estimated time) of injury onset was suggested to be conceptually a better reference point despite potential measurement challenges.

Trauma Center Review
Comments from the trauma centers reflected the panel’s discussion relating to the importance of this indicator, as well as the challenges of implementation. These challenges include difficulties of ascertaining, documenting and obtaining the time of injury and first medical contact. The trauma centers reported that current EMS practices do not consistently report the data required for this quality indicator and therefore changes in data reporting may be required to implement the indicator.

Review of Literature & Evidence
Face Validity: In one study, 88% of Delphi panel participants ranked need for developing scene time limits and auditing violations as very important13.

Construct Validity:Three studies have shown an association between scene time and increased ICU and hospital length of stay, but an inconsistent association with hospital mortality14,15,16.
Reliability: No studies identified.
Risk Adjustmentß: A list of potential variables for risk adjustment is available from studies examining this indicator12.
Utilization: Measures of prehospital time are used as an indicator by a large number of trauma centers: USA 64% (127/200), Canada 17% (6/35), Australasia 50% (6/12).

There is evidence that prehospital times can be decreased through the use of global positioning systems17,18, flashing light protocols19 and different methods of transportation (helicopter versus ground ambulance)20, but there is an inconsistent association of this time interval with mortality14,15,16.

The American College of Surgeons Committee on Trauma proposed ambulance scene time >20 minutes and patients transferred to another health facility after spending >6h at the initial hospital as audit filters2. Rosengart et al. proposed developing scene time limits using a Delphi panel of trauma experts13. Several variations of prehospital time indicators were identified by trauma centers.


2. American College of Surgeons Committee on Trauma. Resources for Optimal Care of the Injured Patient 2006. Chicago: American College of Surgeons; 2006.
12. Newgard CD, Schmicker RH, Hedges JR, et al. Emergency medical services intervals and survival in trauma: assessment of the "golden hour" in a North American prospective cohort. Ann Emerg Med. 2010;55(3):235-246.
13. Rosengart MR, Nathens AB, Schiff MA. The identification of criteria to evaluate prehospital trauma care using the Delphi technique. J Trauma. 2007;62(3):708-713.
14. Nayduch D, Moylan J, Snyder BL, Andrews L, Rutledge R, Cunningham P. American College of Surgeons trauma quality indicators: an analysis of outcome in a statewide trauma registry. J Trauma. 1994;37(4):565-573; discussion 573-565.
15. Copes WS, Staz CF, Konvolinka CW, Sacco WJ. American College of Surgeons audit filters: associations with patient outcome and resource utilization. J Trauma. 1995;38(3):432-438.
16. Di Bartolomeo S, Valent F, Sanson G, Nardi G, Gambale G, Barbone F. Are the ACSCOT filters associated with outcome? Examining morbidity and mortality in a European setting. Injury. 2008;39(9):1001-1006.
17. Ota FS, Muramatsu RS, Yoshida BH, Yamamoto LG. GPS computer navigators to shorten EMS response and transport times. Am J Emerg Med. 2001;19(3):204-205.
18. Ho J, Lindquist M. Time saved with the use of emergency warning lights and siren while responding to requests for emergency medical aid in a rural environment. Prehosp Emerg Care. 2001;5(2):159-162.
19. Marques-Baptista A, Ohman-Strickland P, Baldino KT, Prasto M, Merlin MA. Utilization of warning lights and siren based on hospital time-critical interventions. Prehosp Disaster Med. 2010;25(4):335-339.
20. Talving P, Teixeira PGR, Barmparas G, et al. Helicopter evacuation of trauma victims in los angeles: Does it improve survival? World J Surg. 2009;33(11):2469-2476.