Chronic Sleep Reduction and School Achievement – Review

MEIJER, A. M. (2008), Chronic sleep reduction, functioning at school and school achievement in preadolescents. Journal of Sleep Research, 17: 395–405. doi: 10.1111/j.1365-2869.2008.00677.x

An interesting study on the effects of chronic sleep reduction on the school results of 7th and 8th grade school children. The conclusion is that chronic sleep reduction affects school achievements negatively, directly and indirectly. How does this work?

Chronic sleep reduction can occur by sleeping too shortly or having poor quality of sleep (interrupted), over a longer period. Consequences of chronic sleep reduction can include:

  • tiredness
  • sleepiness
  • loss of energy
  • emotional instability

“chronic sleep reduction may affect school achievement directly and indirectly via functioning at school, with worse school marks as a consequence.”

Many studies show that sleep duration and sleep quality are related to school achievements and functioning at school (Curcio et al., 2006Fallone et al., 2002Wolfson and Carskadon, 2003).

“sleep quality, but not time in bed, appeared to be related to functioning at school of preadolescents”

It would be too easy to say that all kids should be put in bed for x number of hours, and school results would skyrocket. As you can read in the article, ‘time in bed’ is not the only factor in sufficient sleep, and perhaps only a minor one. Also, the perfect amount of sleep is different for every individual child.

Because chronic sleep reduction gives typical symptoms like the ones described above, it is easier to determine the extent of the sleep reduction by checking the severity of these symptoms, than to asses if their ‘time in bed’. In this study, the author developed a questionnaire called the ‘Chronic Sleep Reduction Questionnaire’, which assesses aspects like sleep latency, number of awakenings at night, sleep latency after awakenings and perception of sleep quality and feeling rested after sleep. These are also criteria for insomnia as provided in the DSM IV (American Psychiatric Association (APA), 1994)

A big part of the article is devoted to explaining the statistical methods used, and assessing the quality of the data. One thing that stood out from the results is that girls tend to have higher scores, which means their chronic sleep reduction was more severe. I wonder why that is!

A good paper to read on how to set up such a user research project. However, on the whole I missed a vision on how to use these data. Which children slept best/longest, and did they have better school results? What did they do right? Of the children who were sleep deprived, why were they? Were their lives too busy, or did they have physical trouble with sleeping? Worries? New boy/girlfriend?

Perhaps these are questions for a larger study, and perhaps I will find answers in other literature. If not, I can set up my own research!

Interesting link: adolescent developmental changes in the sleep–wake regulatory (Carskadon et al., 1993)

A good learning point for me in this paper, are the various statistical terms like Cronbach’s Alpha etc. Since I wanted to learn more about statistics this semester anyway, I will look up these terms and learn something. When I do, I will put a little dictionary on this blog.

For more literature on sleep, see this post.


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