Electroencephalography at home shows that you should not trust a subjective sleep assessment

Researchers from the University of Tsukuba have found significant discrepancies between subjective and objective assessments of sleep.

The study, published in the journal Proceedings of the National Academy of Sciences, found that 66% of people who considered their sleep poor had no objective sleep problems, while 45% of those who considered their sleep adequate were objectively experiencing sleep deprivation.

These findings emphasize the unsuitability of subjective sleep assessments for early diagnosis and effective intervention in sleep disorders, highlighting the critical role of objective tools such as sleep electroencephalography.

Accurate sleep assessment is essential for the diagnosis and treatment of sleep disorders, but the limited capacity for memory during sleep makes objective measurements such as electroencephalography (EEG) essential. Despite this, clinically accurate methods of measuring sleep in real-world settings remain limited.

For example, insomnia is a sleep disorder characterized by difficulty falling asleep or maintaining sleep despite the available options. Typically, its diagnosis is based solely on self-report. However, studies have shown that many people with insomnia believe their sleep duration to be significantly shorter than objective measurements indicate.

This discrepancy between subjective and objective sleep estimates can lead to inappropriate treatment strategies, such as trying to increase sleep duration in people who are already getting enough sleep.

Vice versa, people who are unaware of their sleep disorders may not recognize early signs of serious sleep disorders.

To address these issues, S’UIMIN Inc. a startup at the University of Tsukuba, has developed home-useable EEG sleep devices capable of making clinical-level sleep measurements. In this study, researchers conducted a comprehensive analysis of data collected from 421 individuals in Japan who were untreated for sleep disorders.

The data set included EEG recordings of sleep at home over several nights, as well as responses to questionnaires assessing subjective sleep experiences. These subjective and objective assessments were carefully reviewed by physicians, after which the researchers analyzed possible discrepancies.

The results revealed significant discrepancies: 66% of people who considered their sleep poor had no objective sleep problems, while 45% of those who considered their sleep adequate were identified as potentially sleep-deprived. In addition, subjective ratings of “sleep quality” showed minimal correlation with objective measures such as “sleep depth,” “presence or absence of brief awakenings,” and “presence or absence of risk of sleep apnea.”

These data emphasize that it is not advisable to rely solely on subjective assessments of sleep quality when evaluating sleep status. Incorporating objective measures, such as sleep EEG data, into routine medical examinations and providing individualized recommendations based on these data can improve sleep habits and facilitate early detection of sleep disorders.