Work-related Fatigue

It is well understood that the leading cause of work fatalities is motor vehicle crashes, while the leading cause of non-fatal injuries is overexertion and bodily reaction. What is less understood is the role fatigue plays as a contributing factor in occupational injuries and death.

Fatigue is a general term used to describe feelings of drowsiness or tiredness, reduced energy, and the increased effort needed to perform tasks effectively and avoid errors (Dinges, 2001). Although fatigue has long been a safety concern, the current occupational injury surveillance systems managed by the Bureau of Labor Statistics do not track the prevalence of fatigue-related incidents.

Instead, fatigue-related injury estimates are based on a body of research using a variety of methods conducted throughout the world. A systematic review conducted by Uehli (2014) of 27 research studies found that workers with sleep problems have a 1.62 times higher risk of injury than workers without sleep problems. The study also estimates that about 13% of work injuries can be attributed to sleep problems.

Research using data from the National Health Interview Survey finds both shortened sleep duration and more weekly working hours are independently associated with increased risk of a work-related injury (Lombardi et al., 2010). These results are found even after controlling for several socio-demographic, job-related and physical factors. Because sleep and working hours independently impact injury risk, reduced sleep increases injury risk, regardless of number of normal hours worked.

Similarly, an increase in normal hours worked increases injury risk, regardless of the number of normal hours of sleep (Lombardi et al., 2010). As shown in the charts, injury rates are highest among workers who generally sleep less than seven hours per day and workers who typically work more than 40 hours per week. Injury rates peak among workers who regularly get less than five hours of sleep a night (7.89 injuries per 100 employees) and among workers who typically work more than 60 hours a week (4.34 injuries per 100 employees).

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  • Dinges, D.F. (2001). Stress, fatigue, and behavioral energy. Nutrition Reviews, 1 (59).
  • Lombardi, D.A., Folkard, S., Willetts, J.L., & Smith, G.S., (2010). Daily sleep, weekly working hours, and risk of work-related injury: US National Health Interview Survey (2004-2008), Chronobiology International, 27(5): 1013-1030.
  • Uehli, K, Mehta, A., et al. (2014). Sleep problems and work injuries: A systematic review and meta-analysis. Sleep Medicine Reviews, 18.
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