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The impact of on-call work on anxiety, sleep, and cognitive performance in a laboratory environment

posted on 21.10.2019, 00:00 by Madeline Sprajcer
Given the current production and service requirements for many organisations, 24/7 operations have become increasingly commonplace. This has resulted in a greater use of non-standard working arrangements, including shift work, and increasingly, on-call work. Despite being operationally essential for many industries, there has been limited research on the human impact of on-call work. There is evidence to suggest that workers experience increased anxiety surrounding their on-call periods, which has been linked with poorer sleep outcomes. It is well known that poor sleep can result in significant cognitive and work performance decrements. As such, it is vital to understand any changes to anxiety and subsequent sleep, as decrements may have far reaching implications for worker and organisational health and safety. This is particularly pertinent as on-call work is often performed in response to emergency situations or in workplaces with high levels of safety risk (i.e., emergency services, healthcare, power network services). Despite the potentially severe consequences of impaired cognitive performance when on-call, no research has determined which components of on-call work may lead to increased worker anxiety and poorer sleep. Additionally, little previous research has investigated the effects of on-call periods decoupled from the sleep restriction that accompanies the calls and call-outs themselves. As such, this thesis investigates how certain components of on-call work affect anxiety, sleep, and cognitive performance in a laboratory context, without the confounding effect of shortened or interrupted sleep periods. This thesis consists of three studies, each designed to address one component of on-call work thought to cause anxiety. Seventy-two healthy, male participants were recruited to participate in a four-night laboratory study in the Appleton Institute’s time-isolated sleep laboratory (n = 24 per study). The same methodology was employed in each study, aside from the on-call conditions they comprised. The four nights of each study were; an adaptation night, a control night (not on-call), and two counterbalanced on-call nights designed to address specific on-call components. These components were; Study 1: The likelihood of receiving a call (on-call conditions = definitely and maybe; Chapter 3), Study 2: How stressful the tasks to be performed on-call are (on-call conditions = high stress and low stress; Chapter 4), and Study 3: The perceived chance of missing the alarm (on-call conditions = high chance and low chance; Chapter 5). Participants were given instructions regarding their on-call status prior to bed each night. Outcome measures included pre-bed state anxiety, sleep (as measured by both polysomnography and quantitative electroencephalographic assessment), and next day cognitive performance. The effect of trait anxiety on state anxiety, sleep, and cognitive performance was measured across all three studies. The relationship between trait anxiety and each of these outcome variables was examined in the context of each on-call component, to determine if higher levels of trait anxiety result in poorer tolerance of on-call work (Chapter 6). Results indicated that conditions with uncertainty around the on-call alarm resulted in poorer sleep and cognitive performance. These differences were seen when participants were instructed that they may be called (Chapter 3), and when there was a high chance of missing the alarm (Chapter 5). Further, next day cognitive performance improved when participants performed a high stress task on-call, compared with a low stress task, potentially as a result of increased physiological and psychological arousal (Chapter 4). However, the magnitude of these changes was limited. When the effect of trait anxiety was examined in the context of these three studies, it appeared that individuals with lower trait anxiety were no more tolerant of on-call working arrangements than those with higher trait anxiety (Chapter 6). From this thesis we can conclude that there are some components of on-call work that affect anxiety, sleep, and cognitive performance outcomes more than others. Specifically, the uncertainty around calls seems to produce the most noticeable decrements, though these decrements were not large in magnitude. The findings of this thesis suggest potentially simple, cost-effective strategies for minimising the uncertainty surrounding on-call periods (e.g., a backup call system, or the identification and management of call likelihood). Additionally, findings suggest that there may be some protective effects of performing high stress tasks on cognitive performance on-call. However, it is important to note that this protective effect was apparent under laboratory conditions with just one high stress on-call night, and must be interpreted with caution. These findings are presented with a view to making on-call periods safer and more productive for workers and organisations.



Central Queensland University

Additional Rights

I give permission for the digital version of my thesis to be made available on the web, via CQUniversity’s institutional repository, ACQUIRE, for the purpose of research or private study, unless permission has been granted by the University to restrict access for a period of time

Open Access


Era Eligible



Sally Ferguson ; Sarah Jay ; Grace Vincent

Thesis Type

Doctoral Thesis

Thesis Format

With publication