Emergency Medical Services Intervals and Survival in Trauma: Assessment of the “Golden Hour” in a North American Prospective Cohort

      Study objective

      The first hour after the onset of out-of-hospital traumatic injury is referred to as the “golden hour,” yet the relationship between time and outcome remains unclear. We evaluate the association between emergency medical services (EMS) intervals and mortality among trauma patients with field-based physiologic abnormality.


      This was a secondary analysis of an out-of-hospital, prospective cohort registry of adult (aged ≥15 years) trauma patients transported by 146 EMS agencies to 51 Level I and II trauma hospitals in 10 sites across North America from December 1, 2005, through March 31, 2007. Inclusion criteria were systolic blood pressure less than or equal to 90 mm Hg, respiratory rate less than 10 or greater than 29 breaths/min, Glasgow Coma Scale score less than or equal to 12, or advanced airway intervention. The outcome was inhospital mortality. We evaluated EMS intervals (activation, response, on-scene, transport, and total time) with logistic regression and 2-step instrumental variable models, adjusted for field-based confounders.


      There were 3,656 trauma patients available for analysis, of whom 806 (22.0%) died. In multivariable analyses, there was no significant association between time and mortality for any EMS interval: activation (odds ratio [OR] 1.00; 95% confidence interval [CI] 0.95 to 1.05), response (OR 1.00; 95% CI 9.97 to 1.04), on-scene (OR 1.00; 95% CI 0.99 to 1.01), transport (OR 1.00; 95% CI 0.98 to 1.01), or total EMS time (OR 1.00; 95% CI 0.99 to 1.01). Subgroup and instrumental variable analyses did not qualitatively change these findings.


      In this North American sample, there was no association between EMS intervals and mortality among injured patients with physiologic abnormality in the field.
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      Linked Article

      • Have We Killed the Golden Hour of Trauma?
        Annals of Emergency MedicineVol. 57Issue 1
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          The study by Newgard et al1 in the March issue of Annals proposed to set the record straight on the “golden hour” of trauma, one of the best-holding dogmas in medicine.2 They measured the association between emergency medical services (EMS) intervals and mortality among 3,656 trauma patients with substantial abnormal vital signs/mental status, transported by 146 EMS agencies to 51 trauma centers across the United States and Canada. They found no correlation. The associated capsule mentioned that “… time may be less crucial than once thought.  
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