Fatigue has long been recognised as a contributor to workplace incidents. When workers are fatigued their work performance is impaired - and there are many factors that contribute to fatigue - such as hours of work, including extended hours of work and overtime, shift work and the intensity of work. What is often missing from the discussion is sleep.
Sleep deprivation is a significant contributor to fatigue and can occur at many stages of our lives, for many reasons – a growing family, medical or mental health issues, environmental factors etc. Insufficient sleep has been associated with impaired cognitive functioning, more frequent errors, slower information processing and diminished task performance. This clearly has serious safety implications.
With sleep deprivation being identified as a major contributor to fatigue, researchers from Australia, China and the US investigate whether implementing sleep management systems can help to alleviate this hazard?
To date, most studies into the impact of sleep on safety outcomes have focussed on the healthcare and construction industry – this could be because they are both high-stress industries. The highest frequency of self-reported sleep problems however, come from service, health and manufacturing employees, suggesting that it may be irregular work schedules, such as the shift work found in manufacturing that is the contributing factor.
Nurses working 12-hour night shifts were found to experience more significant cognitive difficulties and increased sleepiness by the end of their shifts compared to those on day shifts and studies show that nurses’ ability to self-monitor decreased when they worked a night shift.
Looking at sleep disorders, such as sleep apnoea, insomnia and excessive daytime sleepiness the studies reviewed showed lower safety behaviour scores and more incidents or near misses for those with excessive daytime sleepiness. Employees with insomnia were more likely than others to experience workplace injuries. Among drivers it was found that all of the vehicle incidents reported were among drivers at high risk of obstructive sleep apnoea.
However, everyday sleep problems such as difficulty falling asleep, sleep interruptions, early awakenings, and unsatisfactory sleep were also associated with higher rates of injuries and incidents.
Despite sleep research being conducted for decades, there is always room for more studies. For instance, a number of the studies reviewed in this analysis involved a variety of occupations, but work environments and psychosocial factors differ across occupations. Thus, insights gained from each group of diverse occupations may not inform us on the problems and required interventions.
Although the pathway between sleep, alertness, and incidence occurrence has been established, the gap still needs to be adequately considered. In particular, the intensity and ability of sleep problems to cause reduced alertness invariably, cognitive performance and productivity may vary with the severity of sleep issues.
This study suggests the need to harmonise validated sleep questionnaires for ease of use and to aid comparability of results across studies. It also advocates for using those instruments in company health management. Future studies should focus on auditing sleep management systems to ensure that they are effective and adequately integrated into broader safety practices.
