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Disaster Metrics: A Proposed Quantitative Model for Benchmarking Prehospital Medical Response in Trauma-Related Multiple Casualty Events

  • Jamil D. Bayram (a1) and Shawki Zuabi (a2)

Quantitative benchmarking of trauma-related prehospital response for Multiple Casualty Events (MCE) is complicated by major difficulties due to the simultaneous occurrences of multiple prehospital activities.


Attempts to quantify the various components of prehospital medical response in MCE have fallen short of a comprehensive model. The objective of this study was to model the principal parameters necessary to quantitatively benchmark the prehospital medical response in trauma-related MCE.


A two-step approach was adopted for the methodology of this study: an extensive literature search was performed, followed by prehospital system quantitative modeling. Studies on prehospital medical response to trauma injuries were used as the framework for the proposed model. The North Atlantic Treaty Organization (NATO) triage categories (T1-T4) were used for the study.


Two parameters, the Injury to Patient Contact Interval (IPCI) and Injury to Hospital Interval (IHI), were identified and proposed as the principal determinants of the medical prehospital response in trauma-related MCE. IHI is the time interval from the occurrence of injury to the completion of transfer of care of critical (T1) and moderate (T2) patients. The IHI for each casualty is compared to the Maximum Time Allowed described in the literature (golden hour for T1 and Friedrich's time for T2). In addition, the medical rescue factor (R) was identified as the overall indicator for the prehospital medical performance for T1 and T2, and a numerical value of one (R = 1) was proposed to be the quantitative benchmark.


A new quantitative model for benchmarking prehospital response to MCE in trauma-related MCE is proposed. Prospective studies of this model are needed to validate its applicability.

Bayram J, Zuabi S. Disaster metrics: a proposed quantitative model for benchmarking prehospital medical response in trauma-related multiple casualty events. Prehosp Disaster Med. 2012;27(2):-7.

Corresponding author
Correspondence: Jamil D. Bayram, MD, MPH EMDM, MEd Johns Hopkins School of Medicine 5801 Smith Avenue Davis Building, Suite 3220 Baltimore, Maryland 21209 USA E-mail
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1. Blackwell TH, Kaufman JS. Response time effectiveness: comparison of response time and survival in an urban EMS system. Acad Emerg Med. 2002;9:288-295.
2. Newgard CD, Sears GK, Rea TD, et al. . The Resuscitation Outcomes Consortium Epistry-Trauma: design, development, and implementation of a North American epidemiologic out-of-hospital trauma registry. Resuscitation. 2008;78:170-178.
3. Pons PT, Haukoos JS, Bludworth W, et al. . Paramedic response time: does is affect patient survival? Acad Emerg Med. 2005;12:594-600.
4. Grossman DC, Kim A, MacDonald SC, et al. . Urban-rural differences in prehospital care of major trauma. J Trauma. 1997;42:723-729.
5. Feero S, Hedges JR, Simmons E, et al. . Does out-of-hospital EMS time affect trauma survival? Am J Emerg Med. 1995;13(2):133-135.
6. Esposito TJ, Maier RV, Rivara FP, et al. . The impact of variation in trauma care times: urban versus rural. Prehosp Disaster Med. 1995;10(3):161-166.
7. Mullins RJ, Veum-Stone J, Helfand M, et al. . Outcome of hospitalized injured patients after institution of a trauma system in an urban area. JAMA. 1994;271:1919-1924.
8. Samplais JS, Lavoie A, Williams JI, et al. . Impact of on-site care, prehospital time, and level of in-hospital care on survival in severely injured patients. J Trauma. 1993;34:252-261.
9. Spaite DW, Tse DJ, Valenzuela TD, et al. . The impact of injury severity and prehospital procedures on scene time in victims of major trauma. Ann Emerg Med. 1991;20:1299-1305.
10. Clevenger FW, Yarbrough DR, Reines HD. Resuscitative thoracotomy: the effect of field time on outcome. J Trauma. 1988;28(4):441-445.
11. Ivatury RR, Nallathambi MN, Roberge RJ, et al. . Penetrating thoracic injuries: in-field stabilization versus prompt transport. J Trauma. 1987;27:1066-1072.
12. Gervin AS, Fischer RP. The importance of prompt transport in salvage of patients with penetrating heart wounds. J Trauma. 1982;22:443-446.
13. Spaite DW, Valenzuela TD, Meislin HW, et al. . Prospective validation of a new model for evaluating emergency medical services systems by in-field observation of specific time intervals in prehospital care. Ann Emerg Med. 1993;22(4):638-645.
14. Farmer JC, Carlton PK Jr. Providing critical care during a disaster: the interface between disaster response agencies and hospitals. Crit Care Med. 2006;34(3 Suppl):S56-59.
15. Smiley DR, Loboda A, Starling C, et al. . Transformation from planning to operations: emergency medical services in disaster response. Ann Disaster Med. 2004;3:11-12.
16. Pons PT, Cantrill SV. Mass casualty management: a coordinated response. Crit Decisions Emerg Med. 2003;17:7-11.
17. Doyle CJ. Mass casualty incident: integration with prehospital care. Emerg Med Clin North Am. 1990;8(1):163-175.
18. Quarantelli EL. Delivery of Emergency Medical Care in Disasters: Assumptions and Realities. New York, NY: Irvington Publishers Inc; 1983.
19. Carr BG, Caplan JM, Pryor JP, et al. . A meta-analysis prehospital care times for trauma. Prehosp Emerg Care. 2006;10:198-206.
20. 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;55:235-246, e4.
21. Lerner EB, Billittier AJ, Dorn JM, et al. . Is total out-of-hospital time a significant predictor of trauma patient mortality? Acad Emerg Med. 2003;10:949-954.
22. Báez AA, Lane PL, Sorondo B, Giráldez EM. Predictive effect of out-of-hospital time in outcomes of severely injured young adult and elderly patients. Prehosp Disaster Med. 2006;21(6):427-430.
23. Osterwalder JJ. Can the “golden hour of shock” safely be extended in blunt polytrauma patients? Prehosp Disaster Med. 2002;17(2):75-80.
24. Pons PT, Markovchick VJ. Eight minutes or less: does the ambulance response time guideline impact trauma patient outcome? J Emerg Med. 2002;23:43-48.
25. Lerner EB, Moscati RM. The golden hour: scientific fact or medical “urban legend”? Acad Emerg Med. 2001;8:758-760.
26. Petri RW, Dyer A, Lumpkin J. The effect of prehospital transport time on the mortality from traumatic injury. Prehosp Disaster Med. 1995;10(1):24-29.
27. Pepe PE, Wyatt CH, Bickell WH, et al. . The relationship between total prehospital time and outcome in hypotensive victims of penetrating injuries. Ann Emerg Med. 1987;16(3):293-297.
28. Baxt WG. Trauma—The First Hour. East Norwalk, Connecticut, USA: Appleton-Century-Crofts; 1985.
29. Cowley RA. The resuscitation and stabilization of major multiple trauma patients in a trauma center environment. Clin Med. 1976;83:16-22.
30. de Boer J. Order in chaos: modeling medical management in disasters. Eur J Emerg Med. 1999, Jun;6(2):141-148.
31. Trunkey DD. Trauma. Sci Am. 1983;249:28-35.
32. de Boer J, van Remmen J. Handbook of Disaster Medicine. Utrecht: Van der Wees; 2000.
33. de Boer J, Brismar B, Eldar R, et al. . The medical severity index of disasters. J Emerg Med. 1989;7:269-273.
34. Feliciano DV, Anderson GV, Rozycki GS, et al. . Management of casualties from the bombing at the Centennial Olympics. Am J Surg. 1998;176(6):538-543.
35. Bayram JD, Zuabi S, Subbarao I. Disaster metrics: quantitative benchmarking of hospital surge capacity in trauma-related multiple casualty events. Disaster Med Public Health Prep. 2011;5(2):117-124.
36. Hirshberg A, Scott BG, Granchi T, Wall MJ Jr, Mattox KL, Stein M. How does casualty load affect trauma care in urban bombing incidents? A quantitative analysis. J Trauma. 2005;58(4):686-693; discussion 694-695.
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Prehospital and Disaster Medicine
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