Aeromedical retrieval of trauma patients: Impact of flight path model on estimates of population coverage

K Lorraine Stone; W Andrew Smedley; John Killian; Shannon W Stephens; Russell L Griffin; Daniel B Cox; Jeffrey D Kerby; Jan O Jansen

doi:10.1016/j.amjsurg.2020.01.056

Aeromedical retrieval of trauma patients: Impact of flight path model on estimates of population coverage

Am J Surg. 2020 Sep;220(3):765-772. doi: 10.1016/j.amjsurg.2020.01.056. Epub 2020 Feb 4.

Authors

K Lorraine Stone¹, W Andrew Smedley², John Killian³, Shannon W Stephens⁴, Russell L Griffin⁵, Daniel B Cox⁶, Jeffrey D Kerby⁷, Jan O Jansen⁸

Affiliations

¹ School of Medicine, University of Alabama at Birmingham, Birmingham, AL, USA. Electronic address: klstone@uab.edu.
² School of Medicine, University of Alabama at Birmingham, Birmingham, AL, USA. Electronic address: asmedley@uab.edu.
³ Department of Surgery, University of Alabama at Birmingham, Birmingham, AL, USA. Electronic address: jtkillian@uabmc.edu.
⁴ Center for Injury Sciences, University of Alabama at Birmingham, Birmingham, AL, USA. Electronic address: swstephens@uabmc.edu.
⁵ Center for Injury Sciences, University of Alabama at Birmingham, Birmingham, AL, USA; Department of Epidemiology, University of Alabama at Birmingham, Birmingham, AL, USA. Electronic address: rlgriffin@uabmc.edu.
⁶ Center for Injury Sciences, University of Alabama at Birmingham, Birmingham, AL, USA. Electronic address: danielcox@uabmc.edu.
⁷ Center for Injury Sciences, University of Alabama at Birmingham, Birmingham, AL, USA. Electronic address: jkerby@uabmc.edu.
⁸ Center for Injury Sciences, University of Alabama at Birmingham, Birmingham, AL, USA. Electronic address: jjansen@uabmc.edu.

Abstract

Background: The aim of this study was to compare the impact of different flight path models on the calculated population coverage of aeromedical retrieval systems, using the state of Alabama as a case study.

Methods: Geospatial analysis of U.S. Census Bureau population data using helicopter bases and trauma centers as foci of either circular or elliptical coverage areas.

Results: Circular isochrone models around helicopter bases or trauma centers suggest that the entire population of Alabama could reach a level I or II trauma center within 60 min. Elliptical isochrones, incorporating outbound and inbound flights, suggest that only 78.8% of the population have ready access to level I or II trauma centers.

Conclusion: While all three flight path models described have some validity and utility, simplistic circular flight time isochrones around trauma centers and helicopter bases provide overly optimistic estimates of population coverage. The elliptical model provides a more realistic evaluation.

Keywords: Aeromedical; Helicopter; Isochrone; Population coverage; Trauma.

MeSH terms

Air Ambulances / statistics & numerical data*
Alabama
Humans
Models, Theoretical*
United States
Wounds and Injuries*

Grants and funding

T32 DK007545/DK/NIDDK NIH HHS/United States