Research

Best sleeping time for shift workers

A team of sleep disorder experts  from Brigham and Women's Hospital in the US has identified a simple strategy for sleeping between night shifts that can reduce the risk of fatigue and safety incidents at work.

Participants in the study, who worked consecutive 11pm-to-7am night shifts, were instructed to stay awake until 1pm after each shift, and then remain in bed until an hour or two before the next shift.

They found that although it is difficult to achieve long and consolidated sleep in the daytime, the participants were able to sleep for the same duration as they did while on day shifts. These workers slept nearly two hours more each night than a control group that did not receive any sleep instructions, and performed better on vigilance and alertness tasks during the shift.

"Sleeping in the morning just after finishing overnight work results in a long wake duration and increases the pressure for sleep on the subsequent night shift," the researchers said. Prolonged wake duration, insufficient sleep and working while the circadian rhythm is promoting sleep combine to impair cognitive performance on night shifts, causing an increase in incidents during the shift and on the commute home.

The researchers say their findings show behavioural change controlled by an individual worker – spending eight hours in bed and waking close to the start of a night shift – allows them to acquire sleep and improve night shift performance. "This simple intervention could be a potential non-pharmacological strategy to help shift workers and should be further explored."

The participants were also told to make their bedroom as dark and quiet as possible, and to turn off their phone when they went to bed. The researchers said better sleep hygiene contributed to longer sleep duration, with the control group workers spending an average of 34 per cent of their time in bed awake compared to only 17 per cent among participants.

Most of the control group went to bed in the morning shortly after each night shift, as 75 per cent of shift workers reportedly do. The researchers said this morning sleep likely satisfies enough of the homeostatic sleep drive that an interruption like noise, or other stimuli, makes it difficult to return to sleep before the next shift.
Read more: Cheryl Martine Isherwood, et al, Scheduled afternoon-evening sleep leads to better night shift performance in older adults.  [Full text] Occupational and Environmental Medicine, online first January 2020, doi: 10.1136/oemed-2019-105916.

Injured workers need mental help

One in three injured Australian workers experience serious secondary mental illnesses, however few access mental health services that could accelerate their recovery and return to work, according to a joint Australian/Canadian study.

The findings, published by BMJ, emphasise the importance of post-injury mental health screening, referral and treatment.  The study of 615 Victorian workers who made a workers' comp claims for musculoskeletal injuries through WorkSafe Victoria between 2014 and 2015 found 181 met the threshold for being assessed as having a serious mental illness in the 12 months after injury.  Of those, only 41 per cent accessed a mental health service, like psychological counselling, psychiatry services or antidepressant and anti-anxiety medication, through the workers' comp system. 

According to the researchers from Monash University and Canada's Institute for Work and Health and the University of Toronto, secondary mental health conditions hinder injured workers' long-term recovery and ability to return to work.
Read more: Christa Orchard, et al, Prevalence of serious mental illness and mental health service use after a workplace injury: a longitudinal study of workers' compensation claimants in Victoria, Australia. [Abstract] Occupational and Environmental Medicine, online first Jan 2020, doi: 10.1136/oemed-2019-105995. Source: OHSAlert

Exposure to metal fumes increases risk of invasive pneumococcal disease

Researchers from Europe, Sth Africa and the US have found that exposure to metal fumes not only increases the risk of welders contracting pneumonia but also increases their risk of contracting invasive pneumococcal disease (IPD). They studied 4438 cases aged 20–65 from a Swedish registry of invasive infection caused by Streptococcus pneumoniae, applied controls and linked these to the Swedish registries for socioeconomic status (SES), occupational history and hospital discharge. They also applied a job–exposure matrix to characterise occupational exposures.