Association between helicopter vs ground emergency medical services and survival for adults with major trauma

JAMA. 2012 Apr 18;307(15):1602-10. doi: 10.1001/jama.2012.467.

Abstract

Context: Helicopter emergency medical services and their possible effect on outcomes for traumatically injured patients remain a subject of debate. Because helicopter services are a limited and expensive resource, a methodologically rigorous investigation of its effectiveness compared with ground emergency medical services is warranted.

Objective: To assess the association between the use of helicopter vs ground services and survival among adults with serious traumatic injuries.

Design, setting, and participants: Retrospective cohort study involving 223,475 patients older than 15 years, having an injury severity score higher than 15, and sustaining blunt or penetrating trauma that required transport to US level I or II trauma centers and whose data were recorded in the 2007-2009 versions of the American College of Surgeons National Trauma Data Bank.

Interventions: Transport by helicopter or ground emergency services to level I or level II trauma centers.

Main outcome measures: Survival to hospital discharge and discharge disposition.

Results: A total of 61,909 patients were transported by helicopter and 161,566 patients were transported by ground. Overall, 7813 patients (12.6%) transported by helicopter died compared with 17,775 patients (11%) transported by ground services. Before propensity score matching, patients transported by helicopter to level I and level II trauma centers had higher Injury Severity Scores. In the propensity score-matched multivariable regression model, for patients transported to level I trauma centers, helicopter transport was associated with an improved odds of survival compared with ground transport (odds ratio [OR], 1.16; 95% CI, 1.14-1.17; P < .001; absolute risk reduction [ARR], 1.5%). For patients transported to level II trauma centers, helicopter transport was associated with an improved odds of survival (OR, 1.15; 95% CI, 1.13-1.17; P < .001; ARR, 1.4%). A greater proportion (18.2%) of those transported to level I trauma centers by helicopter were discharged to rehabilitation compared with 12.7% transported by ground services (P < .001), and 9.3% transported by helicopter were discharged to intermediate facilities compared with 6.5% by ground services (P < .001). Fewer patients transported by helicopter left level II trauma centers against medical advice (0.5% vs 1.0%, P < .001).

Conclusion: Among patients with major trauma admitted to level I or level II trauma centers, transport by helicopter compared with ground services was associated with improved survival to hospital discharge after controlling for multiple known confounders.

Publication types

  • Comparative Study
  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Adolescent
  • Adult
  • Aged
  • Air Ambulances / statistics & numerical data*
  • Ambulances / statistics & numerical data*
  • Cohort Studies
  • Databases, Factual / statistics & numerical data
  • Emergency Medical Services / methods*
  • Female
  • Humans
  • International Classification of Diseases
  • Male
  • Middle Aged
  • Odds Ratio
  • Patient Discharge / statistics & numerical data
  • Propensity Score
  • Rehabilitation Centers
  • Retrospective Studies
  • Severity of Illness Index
  • Survival Analysis
  • Trauma Centers / classification
  • United States
  • Wounds and Injuries / classification
  • Wounds and Injuries / mortality*
  • Wounds and Injuries / therapy
  • Young Adult