Age, task discretion and mining shift work: Their effect on sleep quality

The Australian mining industry has been responsible for much of the growth in shift work with 52% of all employees now working them. But roster arrangements for this type of work are the perpetual thorn in both employers’ and employees’ sides. Contributing heavily to employees’ work-life balance, shifts that lead to partner dissatisfaction or that do not align with their work schedules, and those that hamper a worker’s contribution to their household have been linked to sleep disturbance. There is also a growing body of evidence which observes its negative health effect on shift workers including (but not limited to) anxiety, depression, burnout and substance abuse.

In response, a team of researchers from the Centre for Work, Organisation and Wellbeing comprising Dr Rebecca Loudoun, Professor David Peetz and Associate Professor Georgina Murray (with Central Queensland University’s Dr Olav Muurlink), have analysed findings from phase one (2011) of the Australian Coal and Energy Survey which asked 1319 mine and energy workers and their partners if both saw age combine with a perceived lack of control over the intensity, duration and timing of their shift work tasks to impact upon the worker’s sleep quality and quantity?

On its own, age is the most significant factor in workers’ decreasing tolerance for shift work. As Australia’s workforce ages, calls have been made for more flexibility in the working hours of older workers. Although accepted that physiological, psychological and social disruptions characterise older workers, there is however no empirical evidence to suggest that their need for flexibility is greater than that of younger workers. Dr Loudoun (pictured below)explains:

Dr Rebecca Loudoun
Dr Rebecca Loudoun

“More information is needed about the importance of control over aspects of shift work for different groups of workers and workers in different industries. It is important to know the factors influencing work-life interference for [those at] different ages and at different life-stages…. Substantial differences are likely to exist between [older and younger workers] in life circumstances, home responsibilities, job tasks and work-related experience. Previous studies have found no doubt, for example, that support from partners is critical for adjustment to shift work and indirect evidence suggest[s] that marital quality is associated with disrupted sleep.”

The team found shift control had a positive impact for workers over 50 years of age, leading to significantly lower sleep disturbance. Having a say over work tasks also had significant impact, but irrespective of age, no convincing evidence was found to suggest that it mitigated sleep disturbance.

In an industry characterised by high organisational restraint over workers’ freedom of behaviour, the team conclude that leeway around task discretion was more important for younger (<50 years) workers to minimise sleep disturbance than control over shift scheduling is. Older (>50 years) workers, however, placed importance on both, with scheduling the more critical of the two.

“Further research is needed to determine [though] why the pattern regarding the impact of control of shift variables ‘flips’ in middle age,” adds Rebecca.

This article, entitled ‘Does age affect the relationship between control and work and sleep disturbance for shift workers’ was published in the journal, Chronobiology International (2014, vol. 31, issue 10, pp. 1190-1200).