Diverting Ambulances in Life-Threatening Trauma
Date First Published:
July 17, 2026
Last Updated:
July 17, 2026
Report by:
Hunter Pham MD; Lindsey Rauch MD, Senior EM Resident; EM Faculty (Corewell Health/Michigan State University Emergency Medicine Residency Program)
Search checked by:
Jeffrey S. Jones MD, Research Director
Three-Part Question:
For [adults having experienced life-threatening trauma] [does ambulance diversion to a critical access emergency department] compared to [compared to direct transportation to a trauma center] [decrease mortality]
Clinical Scenario:
A 25-year-old male has sustained a gunshot wound to the thorax in a hunting accident. On-scene, emergency medical services find that he is sitting upright, appears anxious, has jugular venous distention, and has weak peripheral pulses. Bleeding is grossly controlled. Vital signs include a heart rate of 128 bpm, blood pressure of 92/68 mmHg, respiratory rate of 26/min, oxygen saturation of 95% on 4L/min by nasal cannula, and temperature of 36.2 °C. Emergency medical services must decide between taking the patient directly to a level 1 trauma center forty-five minutes away, or to the critical access emergency department five minutes away.
Search Strategy:
Medline 2016-6/26 using PubMed, Cochrane Library (2026), Embase, and Scopus
Search Details:
Primary search string: (trauma OR "major trauma" OR "severe trauma" OR "life-threatening trauma" OR polytrauma OR injur*) AND ("trauma center" OR "trauma centre" OR "level I trauma" OR "level II trauma" OR "tertiary care" OR "regional trauma center") AND ("critical access hospital" OR "community hospital" OR "non-trauma center" OR nontrauma OR "district hospital" OR "rural hospital") AND (prehospital OR "pre-hospital" OR EMS OR "emergency medical services" OR ambulance OR "field triage" OR triage OR "destination decision" OR "direct transport" OR "indirect transport" OR "secondary transfer" OR undertriage) AND (mortality OR death OR survival OR outcome*) NOT (review OR "systematic review" OR "meta-analysis" OR "case report" OR editorial). Limit to adults and English language
Outcome:
227 Studies were found, six addressed the clinical question.
Relevant Paper(s):
| Study Title | Patient Group | Study type (level of evidence) | Outcomes | Key results | Study Weaknesses |
|---|---|---|---|---|---|
| Impact of direct prehospital transport on mortality in patients with severe trauma based on the injury severity score: a nationwide observational study in the Republic of Korea. Kim SJ, Kim K, Kim OH, Park CY. August 2025 South Korea. | Nationwide cohort of adults with severe trauma evaluated according to Injury Severity Score. | Retrospective nationwide observational cohort study | In-hospital mortality; survival according to direct versus indirect transportation | Patients transported to level 1 or 2 trauma centers had a lower mortality rate (23.6%) compared to those transported to level 3 or 4 hospitals (28.0%). Benefits were greatest in patients requiring definitive trauma care. | Retrospective design; potential selection bias; Korean trauma system may not generalize to other trauma systems; residual confounding despite adjustment. |
| Comparison of survival outcomes among older adults with major trauma after trauma center versus non-trauma center care in the United States. Nguyen JK, Sanghavi P. February 2023 United States | Older adults with major trauma receiving care at trauma centers or non-trauma centers. | Retrospective national database cohort study | Mortality; survival after trauma center versus non-trauma center care. | Thirty-day mortality was higher overall at level 1 versus non-trauma centers by 2.2%, Level 1 and 2 trauma centers had similar outcomes. | Restricted to older adults; retrospective design; possible residual confounding; destination decisions were not randomized. |
| Outcomes after motor vehicle trauma: Transfers to level I trauma centers compared with direct admissions. Rozenberg A, Danish T, Dombrovskiy VY, Vogel TR. Sept 2017 United States | Motor vehicle trauma patients transferred to a Level I trauma center versus direct admissions. | Retrospective cohort study. | Mortality; hospital length of stay; complications. | Despite transfer patients having higher adjusted severity scores and higher adjusted risk of mortality, there were no differences in mortality (p = 0.95). | Retrospective design; limited to motor vehicle trauma; transfer patients may have differed significantly from directly admitted patients. |
| Comparing outcomes between patients transferred from a critical access hospital versus directly from scene to a level 1 trauma center. Singhal E, Xu T, Dhanasekara CS, Almekdash H, Anamege D, Lazarus J, Alhaj-Saleh A, Tucker A, Dissanaike S. September 2022 United States | 946 trauma patients in West Texas transported directly from scene to a Level I trauma center (SCENE) or initially stabilized at a critical access hospital before transfer (CAH)). | Retrospective cohort study with propensity score matching. | Survival, ICU length of stay, hospital length of stay, factors associated with outcomes. | The majority of CAH group survived compared to SCENE (p = 0.007). For both groups, baseline factors (e.g., age) were associated with outcomes (p < 0.05). After matching, the two groups had no significant differences in survival, LOS, or ICU stay (p > 0.05). | Single regional trauma system; retrospective design; transferred patients had lower injury severity; significant potential for selection bias. |
| Trauma center vs. nearest non-trauma center: Direct transport or bypass approach for out-of-hospital traumatic cardiac arrest. Wang M-F, Chen C-B, Ng C-J, Chen W-C, Tsai S-L, Huang C-H, Chang C-Y, Tsai L-H, Lin C-C, Chien C-Y. February 2025 Taiwan | Adults with out-of-hospital traumatic cardiac arrest. | Retrospective observational study | Survival to admission and survival outcomes following direct transportation to trauma centers (TC) versus nearest non-trauma centers (non-TC). | The TC and cross-region TC groups demonstrated significantly higher rates of ROSC at 30.6% and 30.5%, respectively, as well as lower mortality rates (95.8% for both), compared to the non-TC group, which had a ROSC rate of 12.0% and a mortality rate of 99.5%. | Limited to traumatic cardiac arrest; retrospective design; applicability to non-arrest trauma patients uncertain. |
| Direct transfer to a tertiary care hospital after traumatic injury is associated with a survival benefit in a resource-limited setting. Yohann A, Kayange L, Purcell LN, Gallaher J, Charles A. January 2022 Malawi | Trauma patients in a resource-limited setting transferred directly to a tertiary hospital versus indirect transfer pathways. | Prospective trauma registry analysis. | Mortality and survival. | Crude mortality was 4.8% for indirect and 2.6% for direct transfers. After adjusting for relevant covariates, odds ratio of mortality was 2.12 (p < 0.001) for indirect versus direct transfers. | Resource-limited healthcare system; external validity to North American trauma systems may be limited; observational design. |
Author Commentary:
Current literature heavily favors direct transportation of traumatic injuries to a tertiary care center over the stabilization of these patients at a critical access emergency department or community hospital. Patients with life-threatening traumatic injuries benefit from timely definitive care more than immediate assessment at the closest available emergency department. This is particularly true regarding severe injuries and traumatic cardiac arrest.
Because of the nature of the question, the available literature is almost entirely observational, and therefore subject to confounding. Within most studies, patients taken directly to tertiary care centers generally differ in acuity and demographic from those initially taken to community hospitals. The 2022 study by Singhal et al is of particular interest given its finding of no significant difference in adjusted outcomes between direct transportation to a tertiary care center and initial stabilization at a community hospital followed by transfer within an established regional trauma system.
Altogether, the available evidence suggests direct transportation to a trauma center should be preferred when transportation times are reasonable and definitive trauma resources are immediately available. Initial stabilization at a community hospital might be a reasonable decision when transportation times are particularly long due to weather or unavailability of trained transportation crews.
Because of the nature of the question, the available literature is almost entirely observational, and therefore subject to confounding. Within most studies, patients taken directly to tertiary care centers generally differ in acuity and demographic from those initially taken to community hospitals. The 2022 study by Singhal et al is of particular interest given its finding of no significant difference in adjusted outcomes between direct transportation to a tertiary care center and initial stabilization at a community hospital followed by transfer within an established regional trauma system.
Altogether, the available evidence suggests direct transportation to a trauma center should be preferred when transportation times are reasonable and definitive trauma resources are immediately available. Initial stabilization at a community hospital might be a reasonable decision when transportation times are particularly long due to weather or unavailability of trained transportation crews.
Bottom Line:
In adults with life-threatening trauma, direct transportation to definitive care at a trauma center is associated with improved survival compared with initial transportation to a non-trauma or critical access hospital; however, in rural trauma systems with prolonged transportation times, initial stabilization at a critical access emergency department followed by rapid transfer may achieve comparable outcomes in specific situations.
Level of Evidence:
Level 2: Studies considered were neither 1 or 3
References:
- Kim SJ, Kim K, Kim OH, Park CY.. Impact of direct prehospital transport on mortality in patients with severe trauma based on the injury severity score: a nationwide observational study in the Republic of Korea.
- Nguyen JK, Sanghavi P.. Comparison of survival outcomes among older adults with major trauma after trauma center versus non-trauma center care in the United States.
- Rozenberg A, Danish T, Dombrovskiy VY, Vogel TR.. Outcomes after motor vehicle trauma: Transfers to level I trauma centers compared with direct admissions.
- Singhal E, Xu T, Dhanasekara CS, Almekdash H, Anamege D, Lazarus J, Alhaj-Saleh A, Tucker A, Dissanaike S.. Comparing outcomes between patients transferred from a critical access hospital versus directly from scene to a level 1 trauma center.
- Wang M-F, Chen C-B, Ng C-J, Chen W-C, Tsai S-L, Huang C-H, Chang C-Y, Tsai L-H, Lin C-C, Chien C-Y.. Trauma center vs. nearest non-trauma center: Direct transport or bypass approach for out-of-hospital traumatic cardiac arrest.
- Yohann A, Kayange L, Purcell LN, Gallaher J, Charles A.. Direct transfer to a tertiary care hospital after traumatic injury is associated with a survival benefit in a resource-limited setting.