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Socioeconomic inequities in insomnia-related symptoms among Japanese adults from 1995 to 2013

Updated: Dec 20, 2022

Original Research By: Yuichiro Otsuka, Ohki Takeshima, Osamu Itani, Yoshiyuki Kaneko, Masahiro Suzuki, Yuuki Matsumoto, and Yoshitaka Kaneitam

Summarized By: Neurobit

Despite the ever-increasing rate of insomnia in developed nations, there is limited awareness of sleep-related issues among Japanese adults relative to their socioeconomic status. For this reason, Yuichiro Otsuka and colleagues (2022) intended to recognize the trends and relative socioeconomic impact of insomnia-related symptoms (IRS) in Japan by utilizing a nationally representative survey.

To do this, the researchers used data from the Comprehensive Study of Living Conditions from 1995 to 2013 and built multivariate Poisson regression models with IRS as the outcome and survey year and socioeconomic status as the explanatory variables. Their analysis included 513,223 Japanese adults. After adjusting for age and gender, the IRS prevalence was the most minimal in 1995, the maximum in 2007, and then decreased from 2007 to 2013.

The research identified a higher occurrence of insomnia-related symptoms among the unemployed, self-employed, and those with the lowest household expenditure levels aged 20-64; particularly among divorced, separated, or single women aged 20-64.

While this relationship was found by the researchers, there were limitations to the study. The study was not able to discount the potential of a reverse cause-effect relationship, nor could it take into account factors such as sleep-related lifestyles. Moreover, the symptoms did not meet the standards of clinical insomnia, and there was a risk of information bias and a small sample size. Therefore, more research should be done to determine if any cause-effect relationships are prevalent and mitigate any biases that impacted the results of the current study.

In sum, the findings from this experiment can be used to create more effective prevention strategies for sleep issues and to provide a basis for monitoring sleep health trends in Japan and other East Asian nations.


Otsuka, C. Y. (2022, December 5). Trends and socioeconomic inequities in insomnia-related symptoms among Japanese adults from 1995 to 2013. - physician's Weekly. Physician's Weekly - A trusted source of medical information for healthcare professionals. Retrieved December 19, 2022, from

Otsuka, Yuichiro, et al (2022).“Trends and Socioeconomic Inequities in Insomnia-Related Symptoms among Japanese Adults from 1995 to 2013.” Journal of Affective Disorders, Elsevier, 1 Dec. 2022, .

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