Sleep loss and poor working conditions are the most important causes of occupational fatigue, which can impair mental and physical performance with the potential for serious errors and injuries.

That's according to a review and update in the October Journal of Occupational and Environmental Medicine, official publication of the American College of Occupational and Environmental Medicine.

Matthew Hallowell, Ph.D., and colleagues at the University of Colorado analyzed previous research to develop a "comprehensive systems model" of the interrelated causes and consequences of occupational fatigue.

Fatigue, which may be acute or chronic, is defined as "a decreased ability to perform activities at the desired level due to lassitude or exhaustion of mental and/or physical strength."

Downward Cycle

Based on available data, the "major drivers" of fatigue were sleep deprivation and factors in the work environment—such as noise, vibration, and temperature.

These causes could all interact with other factors, such as increased work load and long work hours.

The most significant consequences of fatigue were short-term degradation in cognitive and physical functioning.

Occupational fatigue affects more than 20% of U.S. workers, costing billions of dollars in lost productivity and healthcare costs.
Illnesses, human error, and injuries also occurred to a lesser extent.

Evidence suggested that some consequences of fatigue can make other outcomes worse, reinforcing fatigue and leading to a downward cycle.

Steep Cost of Occupational Fatigue

Occupational fatigue affects more than 20% of the U.S. working population, resulting in more than $136 billion in lost productivity and healthcare costs each year.

Unfortunately, the problem of fatigue may draw attention only after major accidents, such as the Three Mile Island, Chernobyl, and Exxon Valdez disasters.

Although there has been considerable research on occupational fatigue, fewer studies have been conducted to replicate and validate those findings.

Hallowell and colleagues hope their model will help occupational health professionals and researchers to better understand the interrelated causes and consequence of fatigue.