The number of Canadians working non-standard hours, such as nights and rotating shifts, has increased dramatically in recent decades. Between 1996 and 2006, the number of women in rotating and night shift work increased by 95%, primarily in the health care sector.  For men, the increase was 50%, mostly in manufacturing and trades.

Why should safety coordinators care about this trend? Because Canadians who work night and rotating shifts are almost twice as likely to be injured on the job than those working regular day shifts, according to a study by researchers at the University of British Columbia.

The Study

The study, published in the current issue of the Scandinavian Journal of Work, Environment and Health, examined data on more than 30,000 Canadians collected as part of Statistics Canada’s Survey of Labour and Income Dynamics and compared results between workers involved in different types of shift work from 1996-2006.

The study found that although the overall rate of work injuries in Canada decreased during the time period studied, the injury rate didn’t decline for night shift workers. “The disruption of normal sleep patterns due to shift work can cause drowsiness or fatigue, which can lead to workplace injuries,” says Imelda Wong, a PhD Candidate at UBC’s School of Environmental Health and the study’s lead author. “Our research shows that people working rotating and night shifts are more likely to experience an injury than those who work regular day hours.”

The study also found that the risk of work injury associated with shift work was more pronounced for women, especially if they work rotating shifts. The researchers suggest that because women are more likely to be responsible for childcare and household work, they may have more trouble adjusting to shift work and maintaining regular sleep schedules.

Bottom Line

“As more and more workers become involved in non-daytime shift work, we may see an increase in injuries, especially among women,” says co-author Chris McLeod, a research associate at UBC’s Centre for Health Services and Policy Research. “Regulatory agencies and employers need to consider policies and programs to help reduce the risk of injuries among shift workers.”

Failing to take this research to heart could have serious consequences, especially financially. For example, in 2006, 307,000 work-related injury claims associated with shift work represented more than $50.5 million in costs to Canada’s workers’ compensation system.