Sleep Time and Insomnia Factors Among Professional Flight Members (SOMNAVI)

Prevalence and Factors Associated With Insomnia and Sleep Time in a Sample of Professional Flight Members

Sleep is a physiological function that plays an essential role in many somatic, cognitive or psychological processes. Although the criteria for sleep effectiveness are multiple, its quantity is unanimously recognized as a major determinant of health. Too little sleep time is indeed associated with an increase in metabolic, cardiovascular and accidental morbidity and mortality, caused by sleepiness during journeys or at the workplace. In the wake of recent work in the general French population, a specific study on the prevalence and factors associated with sleeping time and chronic insomnia among flight members appears relevant. Chronic insomnia and sleep debt can thus be assumed to be more common among aircrews than in the general population, due to these specific operational constraints. Better consideration of certain sleep disorders in professional flight members could make it possible to adapt prevention or countermeasures strategies intended to optimize risk management with regard to flight safety.

Study Overview

• Status: Recruiting
• Conditions: Chronic Insomnia; Sleepiness
• Intervention / Treatment: Other: Sleeping condition self-questionnaire

Detailed Description

Today, time dedicated to sleep is in competition with working time, transport time or time spent on new technologies, in a professional or recreational setting. Faced with the public health issue thus raised, studies have highlighted the interest of studying the relationships between sleep time and socio-demographic factors, beyond the mere implication of sleep pathologies. However, among these pathologies, the place of insomnia is not negligible: it is indeed the most frequent sleep disorder (16% of French people in 2010) and represents an important source of involuntary reduction in sleep time, likely to increase inappropriate sleepiness during periods of wakefulness, in the context of activities sometimes involving safety.

Flight crews are exposed to specific operational constraints, both in civilian and military environments, likely to compromise the recovery function of sleep (operational fatigue, extended working ranges, repetitions of time differences, etc.). These constraints, conducive to compromising the levels of vigilance and cognitive performance required, are also at risk of cardio-metabolic complications. They therefore raise the issue of controlling risks and maintaining aviation safety.

The issue of pilot fatigue remains an essential issue for the safety of flight operations. In the context of air transport, several determinants of operational fatigue have been identified, such as irregular sleep schedules, large, irregular and sometimes unpredictable activity ranges, sleep debts, night flights and circadian disturbances in connection with multiple and repeated changes of time zones. If these factors must deal within airlines with rules more often based on alternating "work / rest" than "sleep / wakefulness", the laws and regulations in force, within the aeronautical industry, are now oriented towards scientific approaches to the management of fatigue in commercial aviation, by emphasizing the importance of sleep and taking into account circadian rhythms.

Currently, the vast majority of studies devoted to the sleep of aviation flight personnel are therefore limited to the cases of commercial aviation airline pilots. They have established that most flights, especially over long-haul sectors, involve disturbances of the circadian rhythm, fractionation and restriction of sleep that are harmful to cognitive performance and the risk of accidents. Most publications have looked for associations between sleep measures and performance in an operational context. Some have been able to demonstrate that the classic methods of evaluating sleep in flight (by actimetric readings, sleep diaries or subjective evaluation of self-questionnaires) were correlated with reference data obtained by polysomnography, strongly for the duration of sleep but moderately to weakly for its effectiveness. In the specific case of sleep duration, self-report questionnaires have proven to be a reliable alternative to in-flight actimetric measurements.

The majority of studies have been designed considering pilot sleep as a determinant of in-flight performance, especially during long (12 to 16 hours) and very long (over 16 hours) flights. On the other hand, taking into account the consequences of aeronautical activity on the sleep of pilots is relatively rare in the scientific literature. Thus, most "ecological" studies, known as field studies, generally focus on specific flights with limited time slots and small sample sizes, limiting the scope of the results regarding the effects of flights on sleep. Currently, the main topic of interest is still the sleep of pilots immediately before, during and after duty periods, but without characterizing their baseline sleep, observed during periods of rest.

From this perspective, a study looked at the basic sleep of airline pilots, making comparisons to samples of the general North American population. On a total number of 332 long-haul pilots, the actimetric data revealed longer sleep times during rest periods, highlighting the influence of environmental stresses deemed to be risky to health. In addition, the influence of socio-demographic and professional parameters was reported in a study of 435 pilots. The high prevalence of sleep disorders, drowsiness and fatigue have been documented, as well as an increased risk of fatigue for flight crews on short and medium-haul flights, in connection with the working hours and repetition of rotations.

This study project therefore fits into this global context, in the light of 3 innovative perspectives:

• Target a rich and varied professional panel of aeronautical specialties (not limited to airline pilots only), integrating civil and military status, engaged in distinct operational frameworks but where risk control and aviation safety prevail;
• Recruit a large sample, without current equivalent to our knowledge in the scientific literature;
• Benefit from equivalent and recent data from a study carried out on a very large representative sample of the general French population

• Study Type: Observational
• Enrollment (Anticipated): 2700

Contacts and Locations

• Study Contact: Name: Nicolas Huiban, MD; Phone Number: +33 04 83 16 22 65; Email: nicolas.huiban@intradef.gouv.fr

Study Locations

• France
  • Var
    • Toulon, Var, France, 83000
      • Recruiting
      • Cempn, Hia Sainte Anne
      • Contact: Nicolas Huiban, MD; Phone Number: +33 04 83 16 22 65; Email: nicolas.huiban@intradef.gouv.fr

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years to 60 years (Adult)
• Accepts Healthy Volunteers: Yes
• Genders Eligible for Study: All

• Sampling Method: Non-Probability Sample

Study Population

The study population is composed of military aircrew.

Description

Inclusion Criteria:

• Between 18 and 60 years of age
• Professional flight members
• All aeronautical specialties
• Going for an expert aeromedical visit
• Not opposing the study

Exclusion Criteria:

• Presenting himself/herself for a first medical exam
• Opposition to the study
• Under 18 years of age
• Non-professional aircrew
• Pregnant woman, parturient, breastfeeding
• Person deprived of liberty by a judicial or administrative decision, person undergoing psychiatric treatment by virtue of Articles L. 3212-1 and L. 3213-1 which do not fall under the provisions of Article L. 1121-8
• Adult person subject to a legal protection measure
• Person unable to express consent

Study Plan

How is the study designed?

Number of groups / cohorts

1

Cohorts and Interventions

Group / Cohort	Intervention / Treatment
Professional flight members	Other: Sleeping condition self-questionnaire; Professional flight members will answer a self questionnaire related to their sleeping conditions

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
To describe the average sleep time within a sample of the French professional flight members	Average total nighttime sleep time estimated using a self-administered questionnaire	30 minutes

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Chronic insomnia	Criteria of the International Classification of Sleep Disease (ICSD-3) of the American Academy of Sleep Medicine (items A, B and C of the questionnaire)	30 minutes
Subjective excessive sleepiness Subjective excessive sleepiness	Subjective excessive sleepiness will be estimated on the basis of the replies to the questionnaire : items of Epworth Sleepiness Scale (ESS). The ESS is a self-administered questionnaire with 8 questions. Respondents are asked to rate, on a 4-point scale (0-3), their usual chances of dozing off or falling asleep while engaged in eight different activities. The ESS score can range from 0 to 24. The higher the ESS score, the higher that person's average sleep propensity in daily life, or their 'daytime sleepiness'.	30 minutes
Sleep duration, sleep debt, sleep restriction	Sleep duration, sleep debt, sleep restriction will be estimated on the basis of the replies to the questionnaire	30 minutes
Ideal sleep time	Ideal sleep time will be estimated on the basis of the replies to the questionnaire	30 minutes
Sociodemographic factors	Sociodemographic factors will be estimated on the basis of the replies to the questionnaire Predictive factors of sleep duration, sleepiness and chronic insomnia will be assessed using a top-down liner and/or logistic models taking into account socio-demographic variables	30 minutes
Aeronautical factors	Aeronautical factors will be estimated on the basis of the replies to the questionnaire Predictive factors of sleep duration, sleepiness and chronic insomnia will be assessed using a top-down liner and/or logistic models taking into account occupational variables	30 minutes

Collaborators and Investigators

• Sponsor: Direction Centrale du Service de Santé des Armées
• Investigators: Study Director: Nicolas Huiban, MD, French Army Health Services

Study record dates

Study Major Dates

• Study Start (Actual): October 26, 2021
• Primary Completion (Anticipated): May 1, 2022
• Study Completion (Anticipated): May 1, 2022

Study Registration Dates

• First Submitted: February 16, 2021
• First Submitted That Met QC Criteria: February 16, 2021
• First Posted (Actual): February 21, 2021

Study Record Updates

• Last Update Posted (Actual): March 31, 2022
• Last Update Submitted That Met QC Criteria: March 17, 2022
• Last Verified: March 1, 2022

More Information

Terms related to this study

• Keywords: Sleepiness; Chronic insomnia; Sleeping time; Flight members
• Additional Relevant MeSH Terms: Mental Disorders; Nervous System Diseases; Sleep Disorders, Intrinsic; Dyssomnias; Sleep Wake Disorders; Sleep Initiation and Maintenance Disorders; Sleepiness
• Other Study ID Numbers: 2020-A02069-30

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No