Medical College of Wisconsin
CTSIResearch InformaticsREDCap

Use of a geographic information system to determine appropriate means of trauma patient transport. Acad Emerg Med 1999 Nov;6(11):1127-33

Date

11/24/1999

Pubmed ID

10569385

DOI

10.1111/j.1553-2712.1999.tb00115.x

Scopus ID

2-s2.0-0032758213 (requires institutional sign-in at Scopus site)   62 Citations

Abstract

OBJECTIVE: To determine whether a geographic information system (GIS) and historical transport data can be used to create a map that identifies locations (zones) from which either ambulance or helicopter transport will result in shorter out-of-hospital times.

METHODS: A retrospective, cross-sectional review of a trauma registry was conducted in a two-county region served by a single trauma center. Data were gathered for all patients transported directly to the trauma center between 1993 and 1996. Incident locations and times from first 911 contact until arrival at the trauma center (out-of-hospital time) were extracted. A GIS was used to create a reference map with all incident locations plotted and given z-coordinates corresponding to out-of-hospital time. Two contour surfaces were interpolated: one for all helicopter transports and one for all ground transports. Areas where the helicopter surface was lower than the ambulance surface were designated air zones since helicopter transport resulted in shorter out-of-hospital times. The remaining area was designated a ground zone since ambulance transport resulted in shorter out-of-hospital times. The mean out-of-hospital times were calculated for each mode of transport in both zones and were compared using a two-tailed t-test.

RESULTS: An air zone was identified beginning between 5 and 16 miles from the trauma center. Mean (+/-SD) out-of-hospital time from the air zone was 50 +/- 9 minutes for helicopter transport (n = 54) and 63 +/- 14 minutes for ambulance transport (n = 140). The difference between the means was 13 minutes (p < 0.000001; 95% CI = 8.95 to 17.05). Mean out-of-hospital time from the ground zone was 68 +/-16 minutes for helicopter transport (n = 122) and 32 +/- 14 minutes for ambulance transport (n = 2,047). The difference between the means was 36 minutes (p < 0.000001; 95% CI = 33.59 to 38.41).

CONCLUSIONS: A GIS and historical transport data can be used to create a map identifying locations from which either helicopter or ambulance transport will minimize out-of-hospital time. Inappropriate choice of transport mode is associated with increased out-of-hospital time.

Author List

Lerner EB, Billittier AJ 4th, Sikora J, Moscati RM



MESH terms used to index this publication - Major topics in bold

Aircraft
Ambulances
Cross-Sectional Studies
Decision Making
Female
Geography
Humans
Male
Management Information Systems
Registries
Retrospective Studies
Sensitivity and Specificity
Time and Motion Studies
Transportation of Patients
Trauma Centers
United States
Wounds and Injuries