Are those who work shifts more at risk of work injury?

The number of Canadians working shifts other than a regular daytime schedule is on the rise. A new study suggests that those who work night or rotating shifts are more at risk of getting injured on the job.

Published: February 15, 2011

About 25 to 30 per cent of Canadians work shifts, so understanding their work injury risks may help with prevention efforts. Previous published research suggests that shift work can disrupt normal sleep patterns and cause fatigue, which can lead to work injuries.

Additionally, “shift work may have effects on other dimensions of health,” notes Institute for Work & Health Adjunct Scientist Dr. Christopher McLeod, one of the study’s authors.

To this end, McLeod, along with University of British Columbia (UBC) PhD Candidate Imelda Wong and Occupational Cancer Research Centre Director Dr. Paul Demers, examined data from Statistics Canada’s Survey of Labour and Income Dynamics to explore shift work trends and risk of work injury among Canadians over the period 1996 to 2006.

The researchers defined four types of shift work for this study:

  • regular daytime schedule;
  • regular nights (includes evening and work beginning around midnight);
  • rotating shifts; and
  • other shifts including split shifts, on-call or irregular schedules.

Shift workers at greater risk of work injury

After controlling for other influences on work injury rates, the researchers found that men working night shifts and women working night or rotating shifts experienced a higher rate of injury than regular daytime workers. Women who work rotating shifts are more than two times at risk of work injury compared with their day shift counterparts, says McLeod, also a research associate at UBC’s Centre for Health Services and Policy Research. This was a very strong finding.

McLeod notes that women may be more likely to have to juggle everyday tasks such as childcare needs and household responsibilities. The number of women working rotating and night shifts increased by about 95 per cent over the study period, primarily in health care. That’s almost twice as much as the 50 per cent increase among men, mainly occurring in the manufacturing sector.

Although the estimated number of work injuries resulting in seven days or more of work absence declined by 15 per cent between 1996 and 2006, the injury rate among night shift workers remained stable.

Future research

McLeod hopes to “focus on certain occupations such as those in the health-care and social services sectors” to gain a better understanding of what factors may contribute to worker injury and shift work. We are in a 24/7 economy and shift work is not going to go away, says McLeod. We need to examine the issues to find out how to reduce the risk of injury in shift workers.

The results of the study are published online in the Scandinavian Journal of Work, Environment and Health at