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Prof. dr. Torbjörn Åkerstedt

Prof. dr. Åkerstedt is director of the Stress Research Institute, a joint venture of Stockholm University and the Karolinska Intstitue, Sweden. Åkerstedt has published over 200 scientific papers on sleep. His research area is mainly, sleep regulation, stress and sleep, sleep quality, hours of work and health, sleepiness and security, and the nature of drowsiness. It also includes preventive measures, such as stress management, sleep advice and alertness-enhancing measures.

Sleep Regulation and (Hospital) Shifts

The most obvious work-related sleep disturbance occurs in shift work, that is, in a situation that requires sleep (and work) to be displaced from its presumably optimal temporal position. Shift work can take many forms but this displacement is the key factor.

In health care shift work is associated with increased risk of medical mistakes and of accidents on the road home after a night shift. Sleepiness is increased both subjectively and objectively (EEG), and post-shift sleep is reduced despite an increased need for sleep. On call work is often nothing else than a combination of night and daywork back to back.

Sleep regulatory factors nicely explain the sleep/sleepiness/risk outcome. The circadian trough around 4-5 a.m. will greatly increase sleepiness and risk. To this is added the extended time awake (22h at the end of the night, as compared to the 10h in day work). Finally, the circadian upswing during the morning-noon will curtail sleep displaced to this time. These factors, taken together, will cause the night work sleepiness/risk.

The same factors, when quantified, may also be used to predict this sleepiness/risk, as well as the sleep curtailment. This mathematical modeling may be used to evaluate the effects of work scheduling on sleep, sleepiness and risk.