Related Experiment Video
Updated: Aug 29, 2025
08:36
Collecting Sleep, Circadian, Fatigue, and Performance Data in Complex Operational Environments
Published on: August 8, 2019
12.1K
Self-Reported Sleepiness after 2, 4, and 7 Consecutive Night Shifts and Recovery Days in Danish Police Officers
Marie Aarrebo Jensen1, Helena Breth Nielsen1, Mikael Sallinen2
1The National Research Centre for the Working Environment, 2100 Copenhagen, Denmark.
International Journal of Environmental Research and Public Health
|September 9, 2022
Summary
Consecutive night shifts did not alter sleepiness levels in Danish police officers. This study investigated the impact of varying night shift durations on self-reported sleepiness.
Area of Science:
- Occupational Health
- Sleep Medicine
- Human Factors Engineering
Background:
- Night shift work is linked to reduced sleep duration and increased sleepiness.
- Sleepiness is a known risk factor for accidents and injuries in the workplace.
Purpose of the Study:
- To investigate the effect of consecutive night shifts on self-reported sleepiness.
- To analyze sleepiness patterns across different durations of night shift work.
Main Methods:
- Quasi-experimental, within-subject crossover study involving 73 police officers.
- Participants completed three work schedules: 2, 4, and 7 consecutive night shifts.
- Sleepiness was measured using the Karolinska Sleepiness Scale (KSS) on the last night shift and recovery day.
Main Results:
- Sleepiness levels differed between night shift days and recovery days.
- No significant differences in sleepiness patterns were observed across varying numbers of consecutive night shifts.
- Peak sleepiness occurred before bedtime on both night shift and recovery days.
Conclusions:
- The number of consecutive night shifts did not influence self-reported sleepiness in this cohort.
- Findings suggest that factors beyond the number of consecutive night shifts may contribute to sleepiness in police officers.
Related Concept Videos
01:13Insufficient Sleep and Sleep Deprivation
198
Insufficient sleep refers to not getting the recommended amount of sleep for optimal functioning, even if it's just slightly less than needed. Sleep insufficiency may occur due to lifestyle choices, such as staying up late for social events or work, resulting in routinely getting less sleep than required. For example, consistently sleeping 6 hours when the body needs 7-9 hours can lead to cumulative effects on health and well-being.
Sleep deprivation is a more severe form of sleep loss...
Sleep deprivation is a more severe form of sleep loss...
198
01:24Substance Use Disorders Affecting Sleep
212
Substance use disorders involve a pattern of using drugs more extensively than intended and continuing use despite harmful consequences. This includes legal substances like alcohol and nicotine, as well as illegal drugs. These disorders often involve both physical and psychological dependence, reflecting compulsive use of substances that significantly alter thoughts, feelings, and behaviors, contributing to a major public health issue.
Understanding the concepts of physical dependence,...
Understanding the concepts of physical dependence,...
212
01:07Narcolepsy
180
Narcolepsy is a chronic sleep disorder characterized by pervasive, uncontrolled sleepiness and other sleep disturbances. One of its hallmark symptoms is an abrupt transition to REM sleep upon falling asleep, which causes symptoms typically associated with this phase to occur unexpectedly during wakefulness. These include the following symptoms, which typically last from a minute or two to half an hour.
180
01:24Sleep-Wake Cycles
1.5K
Sleep is an essential physiological process vital to maintaining overall well-being. The reticular activating system (RAS), a network of neurons in the brainstem, regulates wakefulness and sleep. While it may seem passive, sleep consists of distinct cycles, each with its unique characteristics and functions. Two key sleep phases are non-rapid eye movement (NREM) and rapid eye movement (REM).
NREM Sleep
NREM sleep comprises four progressive stages that seamlessly merge:
NREM Sleep
NREM sleep comprises four progressive stages that seamlessly merge:
1.5K
01:15Chronopharmacokinetics: Circadian Rhythms and Influence on Drug Response
116
Circadian rhythms are cyclic changes that are crucial in plasma drug concentrations. Various standard circadian parameters, including core body temperature, heart rate, and other cardiovascular factors, directly impact disease states and the therapeutic response to drug therapy.
The time of drug administration is an important factor to consider, as it can influence the toxic dose of a drug. For example, a study conducted by Prins et al. in 1997 examined the effects of the timing of...
The time of drug administration is an important factor to consider, as it can influence the toxic dose of a drug. For example, a study conducted by Prins et al. in 1997 examined the effects of the timing of...
116