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532
European Journal of Public Health
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The European Journal of Public Health, Vol. 26, No. 4, 532
ß The Author 2016. Published by Oxford University Press on behalf of the European Public Health Association. All rights reserved.
doi:10.1093/eurpub/ckw049 Advance Access published on 28 April 2016
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The contribution of sleep quality and quantity to public
health and work ability
Tea Lallukka1,2, Erkki Kronholm1,3
1 Finnish Institute of Occupational Health, Helsinki, Finland
2 Department of Public Health, University of Helsinki, Helsinki, Finland
3 National Institute for Health and Welfare, Turku, Finland
Correspondence: Tea Lallukka, e-mail: [email protected]
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e all need sleep, and appreciate the importance of good,
Wsufficient sleep for our daily well-being and functioning at
work and during leisure time. People with no sleep problems take
good sleep for granted, but sleep deprivation and different sleep
disturbances are prevalent, and continue to increase across populations. Despite the notable burden of poor sleep on health,1 studies
published on sleep remain relatively scarce in general epidemiological and public health journals.
Although clinical sleep disturbances have been actively examined
in sleep medicine and experimental researchers have figured out the
basic mechanisms underlying control of sleep and wakefulness, epidemiological research integrating sleep with social and public health
is still quite young. We are increasingly more and more aware that
sleep is also a social behaviour closely related to our social
environment.
The first study that reported a U-shaped association between sleep
duration and mortality was published in 1964.2 It showed that
people with sleep duration deviant from the population mean, in
either the short or long direction, were at a higher mortality risk.
During the last decade, the number of epidemiological studies
focusing on sleep has increased sharply, and there is good
evidence that disturbed sleep and sleep deprivation are associated
with mental and somatic ill-health.1 Those with disturbed sleep are
also at a higher risk of work disability3 and potentially premature
mortality.1 Considering what a physiologically active state sleep is, it
is not surprising that its disturbances or deficiency have vital consequences for health and work ability.
Most people need around 7–8 h of sleep to maintain their functioning and well-being. This is also linked to less sickness absence.3
However, sleep need may increase if, e.g. daily work is intense and
requires learning new things. A few percent of people manage well
with very little sleep, whereas others need more sleep than the
average sleep duration of the population. In addition to quantity,
it is necessary to also consider sleep quality, as even with 7–8 h,
health and work ability can be compromised, if sleep is of poor
quality and non-restorative. Health risks, nonetheless, likely
accumulate in the groups with either very short or long sleep
duration combined with poor sleep quality.
With respect to the contribution of sleep to health and work
ability, it is also important to consider chronotype. Thus, even
with similar hours of sleep, ‘evening types’ can be more tired at
work in the morning than ‘morning types’ and may function
better in the evenings. Nonetheless, our society is built to favour
morning types, and typical office hours are likely to better suit those
who are at their best in the mornings. Our vigilance is also affected
by our biological chronotype, and productivity at work is lower at a
certain time in the afternoon, depending on our chronotype.
Furthermore, evening types are at an increased risk of poor sleep
quality, unhealthy lifestyle and other detrimental health outcomes.4
Although work is, in general, good for health, and those who work
tend to sleep better than those outside employment, it is possible
that the nature of current work life and varying working hours
challenge the timing of sleep, and thereby contribute to sleep deprivation or the deterioration of sleep quality over time. Since brain
functions and sleep are connected, sleep need is affected by daily
work tasks. Furthermore, as learning new things and other cognitive
functions require adequate sleep, sleep deprivation is very quickly
seen as lowered cognitive functioning, especially when dealing with
emotions. Sleep deprived can also have more difficulties to make
decisions, especially when solving complex issues. Sleep deprivation
appears to be particularly detrimental for decision-making in
situations involving unexpected change and uncertainty.5
Finally, in addition to work, all the other areas of life, such as
having a spouse, having children, being unemployed, etc., can
also affect sleep quantity and quality. To be able to promote good
sleep and public health, it is important to consider all these aspects.
This helps support the maintenance of good health and work ability
throughout the working life span. Given the high prevalence
and increase in insomnia symptoms among those of working age in
particular, and the strong evidence concerning the adverse health outcomes related to poor sleep,1 we should continue to widen our understanding of the causes and consequences of sleep for public health and
work ability. With respect to public health and the topical efforts to
extend working careers, sleep could play a key role.
Conflicts of interest: None declared.
References
1
Cappuccio FP, Miller MA, Lockley SW, editors. Sleep, Health and Society. From
Aetiology to Public Health. Oxford: Oxford University Press, 2010: 488.
2
Hammond EC. Some preliminary findings on physical complaints from a prospective study of 1,064,004 men and women. Am J Public Health Nations Health
1964;54:11–23.
3
Lallukka T, Kaikkonen R, Härkänen T, et al. Sleep and sickness absence: a nationally
representative register-based follow-up study. Sleep 2014;37:1413–25.
4
Partonen T. Chronotype and health outcomes. Curr Sleep Med Rep 2015;1:205–11.
5
Whitney P, Hinson JM, Jackson ML, et al. Feedback blunting: total sleep deprivation
impairs decision making that requires updating based on feedback. Sleep
2015;38:745–54.