Working long hours increases people's risk of death from stroke and heart disease—and overwork was associated with an estimated 745,000 deaths in 2016, according to a new study from the World Health Organization and the International Labour Organization.
For the study, published in Environment International, researchers conducted two systematic reviews—one incorporating data from 37 studies on heart disease involving over 768,000 people, and one incorporating data from 22 studies on strokes with more than 839,000 people. Then, they calculated employees' health risks using data from several additional sources, including more than 2,300 surveys on working hours conducted among 154 nations from 1970 through 2018.
Because the data ran only through 2018, it didn't cover the Covid-19 pandemic, NPR reports—a development that led many employees to work from home and fundamentally changed how they work.
Overall, the researchers concluded that people who worked at least 55 hours a week are at a 35% increased risk of stroke and a 17% increased risk of dying from heart disease.
Specifically, the researchers estimated that, in 2016, of the 488 million people who worked at least 55 hours a week, 745,000 people died as a result of working those long hours: 398,000 from stroke and 347,000 from heart disease.
That marks a 29% increase in deaths related to overworking since 2000, according to the study, including a 42% increase in heart disease deaths and 19% increase in stroke deaths.
According to the researchers, most of these deaths (72%) occurred among men, and the majority occurred among people ages 60 to 79 who had worked long hours between the ages of 45 and 74.
Regionally, the study found people in Southeast Asia and the Western Pacific region were most commonly exposed to long work hours. In comparison, less than 5% of Americans were exposed to long work hours, according to the study.
Calling the study the "first global analysis of the loss of life and health associated with working long hours," WHO and ILO said "working long hours [is] now known to be responsible for about one-third of the total estimated work-related burden of disease" and "established as the risk factor with the largest occupational disease burden."
The researchers added that while the study did not cover 2020 and the pandemic's effect on how people work, the trend toward overwork—already on the rise for years—was likely exacerbated by the pandemic.
"Teleworking has become the norm in many industries, often blurring the boundaries between home and work," WHO Director-General Tedros Adhanom Ghebreyesus said. "In addition, many businesses have been forced to scale back or shut down operations to save money, and people who are still on payroll end up working longer hours"
To curb address this issue and protect workers' health, the researchers called on employers to be more flexible in scheduling employees, permit employees to share work hours, and to negotiate a maximum number of working hours with employees. The researchers also called on governments to ban mandatory overtime and ensure working hour limits are implemented.
"Working 55 hours or more per week is a serious health hazard," Maria Neira, director of WHO's Department of Environment, Climate Change, and Health, said. "It's time that we all, governments, employers, and employees wake up to the fact that long working hours can lead to premature death."