2.7 Time to Definitive Trauma Center

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Description of Indicator

Relationship to Quality  Medical care should be timely 
Type of Indicator Prehospital process, System level
Proposed Data Source EMS Records, ED Records
Definition Time from onset of injury* to arrival at definitive trauma center
Numerator Time of arrival of injured patient age 18 years and older at definitive trauma center‡ – time of injury*†
Denominator Not applicable
Benchmark Not specified at present
Risk Adjustment Geographic area (urban, rural), initial GCS, ISS, mechanism of injury, type of injuries, entrapment, provider level (type), mechanism of transport (ground, fixed wing, helicopter, combination)

* 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 of arrival at definitive trauma center = time the injured patient arrived at the final trauma center. This may represent the first hospital to which the patient was transported or a subsequent hospital.

† Time to Definitive Trauma Center 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 the entire spectrum of first medical contact and the various routes by which patients may be brought to the definitive trauma center (e.g. ground versus air transport, direct transport from scene versus indirect transport via local hospital). 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. The data recorded for indicator #1 (Time to First Medical Contact) and indicator #7 (Time to Definitive Trauma Care) provide opportunities for calculating multiple time metrics.

Panel Review
Panelists agreed that time is an important factor in patient care and that multiple time metrics can be measured, each with different implications. Similar to the panelists’ comments for the indicator, Time to First Medical Contact, it was suggested that using time of EMS dispatch as the reference point for time measurements may be most practical but that time of injury onset is conceptually better. In addition they highlighted that reporting and/or adjustment for geographic area (urban versus rural, distance from destination), mechanism and type of injuries, complexity of scene (e.g. entrapment), type of provider and mechanism of transport (e.g. ground versus air) is likely to be important for this indicator.
Panelists also discussed implementation of this indicator and the importance of coordinating data collection with EMS.

Trauma Center Review
The trauma centers agreed on the importance of this indicator but were concerned that it is difficult to ensure that documentation is consistent and completed. They indicated that it may be valuable to obtain information relating to reasons for delay, but discussed that this may be difficult to implement and obtain. The difficulty in accurately ascertaining time of injury was noted and trauma centers emphasized the importance of risk adjustment (e.g. geographic area, resources, mode of transport) for this indicator.


Review of Literature & Evidence
Face Validity: In one study, 88% of Delphi panel participants ranked the 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, flashing light protocols18,19 and different methods of transportation (helicopter versus ground ambulance)20, but there is an inconsistent association between this time interval and 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 from 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.