On-call duty is a working arrangement most commonly used in many industries and organisations to cover the risks associated with unforeseeable events, which often require urgent attention and are linked to safety concerns.
A study by an Australian team A recently published study examined the effects of the uncertainty associated with being called out on sleep and cognitive performance during a night on call.
A four-day experimental protocol was carried out, comprising one control night and two simulated on-call nights. The aim of this protocol was to measure subjective anxiety before bedtime, sleep quality and cognitive performance the following day. On one of the two on-call nights, participants were informed that an intervention would definitely take place during the night. On the other night, they were told that an intervention was likely, but not certain. The questionnaire from the State-Trait Anxiety Inventory form x-1, was used to assess anxiety prior to bedtime, whilst polysomnography and spectral analysis were used to analyse the electroencephalogram data recorded during sleep. Cognitive performance was assessed four times a day using a psychomotor vigilance test.
A decline in sleep quality
Whilst the participants felt much more anxious before going to bed when they were certain they would be called, they slept more deeply and exhibited fewer periods of REM sleep (sleep characterised by rapid eye movements) or N2 sleep (light sleep during which the sleeper is easily woken) than on nights when it was uncertain whether they would be woken.
Uncertainty surrounding the procedure would therefore lead to a decline in sleep quality, but would also be linked to impaired cognitive performance the following day. The authors believe that this represents a form of adaptive response to the stress associated with the conditions of the shift work.
The protocol also shows that subjective measures of anxiety did not predict sleep problems or performance issues whilst on duty, highlighting the difficulty of assessing the impact of these phenomena clinically, based on one’s own experience or anecdotal evidence...