Prevalence of sleep disorders in a large French cohort of aircrew members and risk of in-flight sleepiness.

Background: /objectives: Sleep disorders are a critical issue for flight safety. Previous studies have shown a high prevalence of sleep disorders and excessive sleepiness in the general population and some aircrews. The objectives of this study are to measure the prevalence of excessive daytime sleepiness and sleep disorders in aircrews, and to determine the risk factors of falling asleep during a flight.

Methods: this is a monocentric study based on questionnaires, including all professional civilian and military aircrews examined in an aeromedical center between January and May 2021. The questionnaire, created for this study, included information about socio-demographic characteristics, aeronautical experience, lifestyle, sleep habits, an Epworth sleepiness scale, and screening tests for chronic insomnia, sleep apnea syndrome and restless legs syndrome.

Results: 749 aircrew members were included (86.2% male, 58.9% civilian, 74.1% pilot, mean age 43.4 ± 9.6 years), 45.9% of the population had at least one sleep disorder (chronic insomnia 39.5%, sleep apnea syndrome 10.5%, restless legs syndrome 4.1%), 15.5% had an excessive daytime sleepiness, and 24.6% reported in-flight sleep while on duty. Chronic insomnia, screen use before bedtime, use of sleeping pills, inadequate recovery time after a flight, female gender and civilian status were found as risk factors of in-flight sleep in the multivariate analysis.

Conclusion: this study emphasizes the need to improve the screening and prevention of sleep disorders in this particular population.