Many of us, as we toil away during the dog days of August, think enviously of the Europeans with their numerous weeks of vacation. Even at other times of the year, Americans tend to work more hours and take fewer vacations than workers in many other developed countries. But while longer working hours may be helpful to our economy, they appear to be detrimental to our health.

For years, studies have suggested that long working hours could be harmful to the health and well-being of workers. But many of these studies have been limited by a small number of participants or the failure to represent a mix of industries and occupations. In addition, very few of these studies have been conducted in the United States.

In an article published in the September 2005 Occupational and Environmental Medicine , researchers studied the impact of long hours on injury and illness in a large sample of workers, spanning a variety of industries and occupations over more than a decade in the United States. They found that employees working overtime, working 12 or more hours a day, or working 60 or more hours a week were all significantly more likely to have a work-related illness or injury than those not working overtime, working fewer than 12 hours a day, or fewer than 60 hours per week.

About the Study

The researchers analyzed data from the National Longitudinal Survey of Youth (NLSY), which tracked the details of participant’s employment histories for more than 20 years. The NLSY first surveyed 12,686 men and women, aged 14 to 22, in 1979, and then surveyed them annually until 1994, then biannually after 1996. The survey collected information about sociodemographic status, education, training, work histories, job and employer characteristics, income, health insurance, and any work-related illness or injury or episodes of work disability.

For this study, researchers examined the records of 10,793 of those individuals between the years 1987 and 2000. A job record was created for every position held by each survey respondent. This resulted in a total of 110,236 job records created during the period of this study.

The participants’ working hours were categorized as:

Extended hours per week : participants regularly working more than 60 hours per week

Extended hours per day : participants regularly working more than 12 hours per day

Overtime : survey respondents answered “yes” to whether they work overtime (no specified definition of overtime given)

Extended commute time : commute time of more than two hours per day

Overtime or extended hours : study subjects qualified for any of the preceding four categories

Study participants could qualify in more than one category.

The incidence of work-related injury or illness in people who had worked overtime or extended hours was compared to the incidence of work-related injury or illness in those who had not.

The Findings

Out of the 110,236 available job records, 5,139 work-related injuries and illnesses were reported during the period of the study.

Even after taking age, gender, occupation, industry, and geographic region into account, the researchers found that study participants working in a job with overtime were 61% more likely to have a work-related injury or illness than participants working in a job with no overtime. Employees working 12 or more hours per day had a 37% increased risk of work-related illness or injury compared to employees working fewer than 12 hours per day, and employees working 60 hours or more per week were at a 23% increased risk for work-related illness or injury compared to employees working fewer than 60 hours per week. These were all significant differences.

Jobs that entailed any type of overtime or extended hours increased the risk of work-related injury or illness by 38%, compared to jobs that entailed no overtime or extended hours.

The researchers also noted that the degree of risk of injury or illness increased with an increase in the number of hours worked over and above 12 hours per day or 60 hours per week.

Extended commute time did not have any impact on job-related illness or injury.

This study was limited by the lack of certain relevant data. For example, the researchers did not consider the participants’ health status, the kinds of job activities being performed, or the specific cause of the injuries.

How Does This Affect You?

This study showed that people who regularly work overtime, or have long workdays or workweeks suffer significantly more work-related injuries and illnesses than people who do not. In addition, the more additional hours put in at work, the greater the risk of injury or illness.

While there are a great many workaholics out there, most people who work very long hours do it out of necessity rather than choice. According to this journal article, for example, up to one-third of overtime in the United States is mandatory.

As a result, it is not realistic to suggest that employees just cut back on their hours. The best thing that overworked people can do is offset the detrimental affects of the extra hours by taking care of themselves in other ways. That means getting regular exercise, adequate sleep, and proper nutrition.

Employers can do their part by incorporating regular rest breaks into their employee’s schedules, or perhaps hiring more people to work fewer hours each. Both employees and employers would benefit from fewer sick days.