Almost four out of 10 Americans suffer from fatigue at work, a problem that is costing the U.S. economy billions of dollars in lost productivity.
A study of nearly 29,000 employees published in the January Journal of Occupational and Environmental Medicine found that 38 per cent said they had experienced "low levels of energy, poor sleep, or a feeling of fatigue" during the past two weeks.
Fatigue was more common in women than men, in workers less than 50 years old, and in white workers compared with African Americans.
Workers with "high-control" jobs relatively well paid jobs with decision-making responsibility also reported higher rates of fatigue, the research found.
The study looked at how fatigue impacts on productive time in terms not just of absenteeism but also presenteeism Ė time when employees are at work but performing at less-than full capacity.
Almost one in 10 (nine per cent) of workers with fatigue reported such unproductive work time. Fatigue reduced work performance mainly by interfering with their concentration and increasing the time needed to accomplish tasks.
The rate of lost productivity for all health-related reasons was also much higher for workers with fatigue: some 66 per cent , compared with 26 per cent for workers without fatigue.
Total lost productive time averaged 5.6 hours per week for workers with fatigue, compared to 3.3 hours for their counterparts without fatigue.
For U.S. employers, this brings with it estimated costs of more than $136 billion per year in health-related lost productivity Ė some $101 billion more than for workers without fatigue. Eighty-four per cent of the costs were related to reduced performance while at work, rather than absences.
Although other studies have found that fatigue is a common symptom that is linked to missed work time, the new study is the first to focus specifically on the rate of fatigue in U.S. workers, and its relationship to worker productivity.
The results underline the fact that fatigue as a major problem in the U.S. workforce, and one with a major impact on productivity and costs.
"Interventions targeting workers with fatigue, particularly women, could have a marked positive effect on the quality of life and productivity of affected workers," the researchers concluded.
They suggest that companies could offer work-life programs to help employees balance their work and personal responsibilities, and take steps to improve assessment and treatment for the large subgroup of workers who have fatigue co-occurring with other health conditions.