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Updated: Aug 27, 2025

Collecting Sleep, Circadian, Fatigue, and Performance Data in Complex Operational Environments
Published on: August 8, 2019
American Helicopter Emergency Medical Service Pilots Report to Work Despite High Rates of Sleepiness
Tovy Haber Kamine1, Hiba Dhanani2, Susan Wilcox3
1Department of Surgery, Baystate Medical Center, Springfield, MA; Department of Healthcare Delivery and Population Science, University of Massachusetts-Medical School-Baystate, Springfield, MA.
Objective:
Previous studies on helicopter emergency medical service (HEMS) pilots found a positive correlation among fatigue, nodding off in flight, and accidents. We sought to quantify the amount of sleepiness in HEMS pilots using the Epworth Sleepiness Scale (ESS).
Methods:
An anonymous survey was sent via the National EMS Pilots Association emergency medical services listserv including demographics, the ESS, and subjective effects of fatigue on flying. Statistical analyses were performed using the t-test and analysis of variance.
Results:
Thirty-one surveys were returned. Twenty-one (65%) reported an ESS > 10, indicating excessive daytime sleepiness. Twelve (39%) reported nodding off in flight; 20 (65%) indicated that they should have refused to fly, but only 14 (45%) actually did. En route was the most likely phase of flight to be affected by fatigue (23 [74%]), whereas takeoff (2 [7%]) and landing (2 [7%]) were the least likely to be affected.
Conclusion:
Many HEMS pilots in this small study reported excessive daytime sleepiness. Most respondents indicated that they should have turned down a flight because of fatigue. More research is necessary to quantify the burden of fatigue among HEMS pilots.
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