title: Helicopter trauma transport: an overview of recent outcomes and triage literature.
abstract: OBJECTIVE
  The purpose of this review is to assess literature pertinent to outcomes benefits accrued by the use of helicopter emergency medical services for trauma transport. A previous annotated bibliography assessed literature published between 1980 and 2000. The goal of this paper is to address developments since fall 2001, and to cast recent studies in the light of earlier work in an attempt to provide a long-range overview of the relevant literature.
  
  
  RESULTS
  In the year covered by this review, we identified four papers that directly assessed the association between the helicopter emergency medical services utilization and trauma outcome, and three that addressed the closely related issue of the helicopter emergency medical services triage appropriateness. An Italian study found no benefit associated with advanced prehospital care for patients with severe head injury. A US multicenter trial assessing blunt trauma transports found a substantial mortality reduction associated with helicopter use. Two other US studies, characterized by a similar 'natural experiment' design of assessing mortality changes on either side of a timepoint at which the helicopter emergency medical services availability ceased, reached opposite conclusions about the benefits of the service. Recent studies addressing the helicopter emergency medical services utilization in terms of triage were characterized by varying levels of agreement with the widely held belief that this service is characterized by overtriage.
  
  
  CONCLUSIONS
  The preponderance of recent and previously extant evidence supports an argument that the helicopter emergency medical services transport is associated with significant benefit for some injured patients. The primary challenges at this time include the determination of which patients benefit and the elucidation of which aspects of the helicopter emergency medical services are responsible for any salutary effects of its utilization.
authors.affiliation: Department of Emergency Services, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts 02114, USA. thomas.stephen@mgh.harvard.edu
authors.forename: Stephen H
authors.initials: SH
authors.lastname: Thomas
authors.forename: Paul D
authors.initials: PD
authors.lastname: Biddinger