Mental health, car crash warnings for shift workers

Shift workers are at greater risk of poor mental health and of crashing their car after their first shift of the week, two separate studies suggest.

In the first, an international team of researchers examined the schedules and mental health symptoms of more than 28,000 participants.

University of Southern Queensland’s Dr Tracy Kolbe-Alexander said working outside standard hours (7:00am to 6:00pm) held potential physical and mental health consequences.

Kolbe-Alexander said shift work was associated with a 28 per cent increased likelihood of adverse mental health outcomes combined. And female shift workers were more likely to report symptoms – particularly depressive symptoms – than women who did not work shifts.

“Night work and inconsistent work hours disrupt the normal sleep-wake cycle,” she said.

“Sleeping at odd times of the day, together with shifting schedules, creates challenges for maintaining healthy work-life balance."

In the car crash study, researchers countered the theory that cumulative effects of night shift increase the likelihood one will occur as time goes on.

They found shift workers were more likely to crash their car after finishing their first night shift of the week rather than later on.

Lead researcher Professor Greg Roach, based at CQUni Adelaide's Appleton Institute, recruited 43 people for simulated shift work in their sleep laboratory.

The participants completed seven consecutive eight-hour night shifts in an office then each day had 20 minute commutes in a driving simulator – one at 10.30pm, as if they were going to work, and one to represent their trip home at 7.10am.

“Most guidelines recommend a maximum of two-to-four consecutive night shifts, based on the notion that fatigue risk increases with each successive night shift due to accumulated sleep loss,” Roach said.

“Our results challenge that notion.”

The study also found the likelihood of a shift worker crashing on the way home from night shift on the first night is eight times greater than the likelihood of crashing on the way to work.