Shift Workers More Likely to Be Injured

By Beth Mirza Dec 2, 2010

A study of Canadian shift workers found that employees who work night or rotating shifts are nearly twice as likely to be injured on the job as daytime workers. The risk was more pronounced for women, University of British Columbia researchers said.

The study was based on data on more than 30,000 Canadians collected for Statistics Canada’s Survey of Labour and Income Dynamics from 1996-2006. The overall rate of work injuries in Canada declined, except for those incurred during night shifts.

Women might be more susceptible to injury because they are more likely to have child care and housekeeping duties and might not be able to maintain a regular sleep schedule, study authors wrote.

Shift work might be inherently dangerous—and costly. CIRCADIAN, which offers workforce performance and safety solutions for companies that operate around the clock, estimates that the typical shift worker costs his or her company $10,000 in turnover, absenteeism, workers’ compensation, lost productivity and medical costs, said Bill Sirois, senior vice president and CEO. Between the hours of midnight and 6 a.m., there is a five times greater risk of accidents, and workers are 15 times more likely to have accidents between 3 a.m. and 6 a.m., he said.

However, “these are preventable accidents,” Sirois said, suggesting three fundamental changes that could help companies save money and protect shift workers:

Hire more workers. “In American industry today, we are so short-staffed that overtime is through the roof,” Sirois said. “[Overtime pay] is great, but people will work themselves to extremes” that are unsafe. CIRCADIAN research shows that 10-12 percent of extra hours of work over and above regularly scheduled hours is manageable and efficient for managing overtime, he said. “This provides safety and a reasonable opportunity for extra money.” New hires are expensive, Sirois acknowledged, but when overtime costs 1.5 times or double the hourly rate and brings with it the possibility of fatigue and human error, new hires might be more affordable for the long run.

Optimize schedules so that they are “bio-compatible.” Humans function best during daylight hours and are wired to sleep during the night. “We applaud those who go the extra mile or do whatever it takes to get the job done, but we have been operating outside our design specifications since the advent of the light bulb,” Sirois said. Companies should provide shift workers adequate time for rest and sleep opportunities around the clock (CIRCADIAN research recommends 20-minute naps as needed or time available), within regulatory requirements and contractual agreements.

Train employees so that they do their part and get the rest they need. Emphasize to them how important sleep is to their health and productivity. Sirois recommends including workers’ partners and spouses in the education campaign so that they can help the employees maintain good habits at home. A little understanding could go a long way: Research from the University of Maryland shows that shift workers experience a 60 percent higher divorce rate. “People shouldn’t come to work to get hurt, sick or destroy their families,” Sirois said. “Shift work affects the entire family structure.”

Sirois suggested that organizations explore ways to make the work environment more stimulating, such as by using brighter paint colors, enhancing lighting and climate control, and providing sound insulation for machines that might create a dull, monotonous, hypnotic noise.

“If you really want to lick the problem, put in place monitoring and feedback loops that are in the same spirit of buddy system monitoring,” Sirois said, by asking employees to pay attention to their co-workers. If someone seems drowsy or is visibly trying to wake himself up, co-workers should take note and try to help him revive himself. Supervisors should be on the lookout for these behaviors and know the appropriate interventions to take.

Beth Mirza is senior editor for HR News. She can be reached at


Job Finder

Find an HR Job Near You
Post a Job


Find the Right Vendor for Your HR Needs

SHRM’s HR Vendor Directory contains over 10,000 companies

Search & Connect