Brain Sleep Co., Ltd. (Headquarters: Chiyoda-ku, Tokyo, CEO: Atsushi Hirota, hereinafter referred to as "Brain Sleep") has been conducting the "Sleep Standard Deviation®" survey since 2020 targeting 10,000 people (allocated by gender, age, and prefecture) in all 47 prefectures nationwide, and 2023 marks the fourth year. The sleep standard deviation is a method of comprehensively scoring productivity, stress level, risk of sleep apnea syndrome (SAS), etc. in addition to items that directly assess sleep status such as sleep habits and sleep debt. In the future, we will utilize the results of this survey to carry out various activities aimed at further improving sleep in Japan. Sleep Deviation Value® Survey Results Pagehttps: //brain-sleep.com/service/sleepdeviationvalue/research2023/ ■Survey results summary Brain Sleep has created the "Sleep Standard Deviation®" from various sleep-related scales, and has been working to understand the actual sleep status of Japanese people and to develop health management services for corporate employees. This time, we conducted a measurement of the 2023 version of the sleep standard deviation and clarified the characteristics of Japanese sleep in the following six new items. 1. Sleep deviation scores by gender and age 2. Changes in sleep times in Japan 3. Ranking of factors that lead to poor sleep quality by gender 4. The relationship between productivity and sleep 5. The relationship between immunity and sleep 6. The relationship between work style (fixed vs. shift) and sleep Comment from Seiji Nishino/Chief Research Advisor of Brain Sleep, author of "The Stanford Way to Get the Best Sleep" The survey results for this year confirmed that, although there are some fluctuations, sleep duration in Japan continues to increase compared to before the COVID-19 pandemic. The extension of sleep duration due to the COVID-19 pandemic and the associated changes in work patterns is a global trend, but it is also recognized that sleep quality is declining, especially under remote work. It has become clear that declining sleep quality not only reduces productivity levels, but also increases the risk of COVID-19 infection. It seems that it is necessary to pay attention to improving sleep quality, especially during a pandemic. In this survey, women's sleep deviation scores tended to be higher than men of the same age, but it is recognized that factors unique to women, such as changes in hormone balance and childcare, reduce women's sleep quality. In addition, as has been pointed out before, shift workers tend to have poorer sleep quality than fixed-hour workers. Considering that declining sleep quality reduces productivity and increases the risk of disease, as well as the current situation in which the number of shift workers is increasing year by year, immediate measures are needed. 1. Sleep deviation scores by gender and age: Men in their 20s have the lowest sleep deviation scores, while women over 60 have the highest! Compared to the past two years, when lifestyles have changed dramatically due to the COVID-19 pandemic, this survey was conducted in January 2023 at a time when infection control measures were being relaxed and daily life was beginning to return to normal. Women tended to have higher sleep deviation scores when compared by gender. This was because men scored higher than women in the quality of sleep category, but had lower results in the productivity and stress categories. In addition, when comparing by generation, men in their 20s had the lowest scores, while women in their 60s had the highest scores. Women in their 60s had scores that were more than 3 points higher than men of the same age. In terms of sleep time, those over 60 had the shortest scores, and the scores tended to get longer as people got younger. Meanwhile, in other areas such as sleep quality, productivity, and stress, the scores were lowest in the 20s, and increased with age. A one-way analysis of variance was performed for men and women by age group, and significant differences were confirmed (p<0.01). 2. Changes in sleep time in Japan: -5 minutes compared to 2022. Same results as in 2021 In previous Brain Sleep surveys, the average sleep time in Japan was 6 hours and 27 minutes in 2020, 6 hours and 43 minutes in 2021, and 6 hours and 48 minutes in 2022, showing a trend of improvement, with sleep time increasing by 21 minutes over the past two years. In this year's survey, the average sleep time in Japan was 6 hours and 43 minutes, 5 minutes shorter than in 2022, returning to the same sleep time as in 2021. Brain Sleep has been conducting similar surveys for four years since its establishment in 2019, and although there has been an increase in sleep time since the initial survey, it is still overwhelmingly shorter than the average sleep time of 8 hours and 25 minutes in OECD member countries, and it can be said that Japan's sleep is still at the lowest level in the world. Brain Sleep will continue to tackle various sleep issues in Japan, which still have room for improvement, and we hope to continue our activities to improve sleep in Japan in the future. *A one-way analysis of variance was performed on all data and significant differences were confirmed (p<0.01). In addition, a t-test was performed to compare sleep time with the previous year and significant differences were confirmed (both p<0.01). 3. Ranking of causes of poor sleep quality by gender: Work ranks high for both men and women. For women, hormonal imbalance is the cause Sleep is essential for people to live a healthy life. Getting enough sleep helps the brain and body recover from fatigue, leading to energy the next day. When evaluating sleep, attention is often focused only on simple quantitative data such as sleep time, but "quality" plays an important role in good sleep. In this survey, out of 10,000 respondents from all 47 prefectures across Japan, 4,287 people answered that their sleep quality was "poor" or "very poor," indicating that nearly half of the people in Japan have issues with their sleep quality. When the possible causes of poor quality sleep were ranked in order of frequency, the top three for men were all work-related. For women, the top two were work-related, as for men, but third place was hormonal imbalance and changes, which also revealed health issues unique to women, such as menstruation, pregnancy, childbirth, and menopause. When women who answered that they had issues with the quality of their sleep due to menstruation, pregnancy, childbirth, or menopause were asked to answer questions about the number of days per month they felt sleepless, broken down by cause, we found that the average was 5.7 days for menstruation (including before and after), 10.4 days for pregnancy and childbirth, and 7.3 days for menopause. 4. The relationship between productivity and sleep: Productive people have better quality sleep It is known that poor sleep quality has a significant impact on work performance and leads to losses for companies. Many industrial accidents are said to be caused by lack of sleep or sleep disorders. In this survey, we once again investigated the relationship between productivity and sleep. When people self-assessed their productivity with 100% as the maximum, no clear relationship was found with sleep time, but a correlation with sleep quality scores was found. People who answered that their productivity was level 3 or above (self-assessed productivity of 51-75%) had a sleep quality score of 70 points or above, and the closer they were to level 4 (76-100%), the higher their sleep quality scores tended to be. When it comes to sleep, it has traditionally been said that while sleep duration is important, sleep quality is even more important. The results of this study, which showed that productivity evaluation has a stronger correlation with sleep quality than sleep duration, further support this idea, and it can be said that improving sleep quality may also improve productivity. *One-way analysis of variance was performed on "sleep time" and "sleep quality," and significant differences were confirmed (p<0.01). 5. The relationship between immunity and sleep: The key to immunity is quality of sleep With the COVID-19 pandemic since 2020, the importance of sleep in improving immunity and increasing the effectiveness of vaccines has been recognized once again. In this survey, we also investigated the relationship between the number of COVID-19 infections and sleep deviation score to confirm the possibility that sleep quality affects immunity. Among the respondents, 2,276 people (22.8% of all respondents) had contracted COVID-19 once. The largest number of people who had contracted the virus was 12 people, who had contracted it five or more times, though this was only 0.1% of the total. When comparing the sleep deviation scores of people who have had COVID-19 at least once with those who have not, the results showed that those who had the virus had a significantly lower sleep deviation score. It was also found that the more times people have had the virus, the lower their sleep deviation score tends to be. The results of this survey only evaluate current sleep deviation scores and do not indicate a causal relationship between poor health and sleep state over the past year, but it is possible that people who have contracted COVID-19 have a weakened immune system, which is caused by sleep problems, resulting in a low sleep deviation score. Sleep plays a very important role in maintaining health, and in order to overcome COVID-19 and live healthy lives every day, it is necessary to be more conscious of sleep than ever before. *One-way analysis of variance was performed on "sleep time" and "sleep quality," and significant differences were confirmed (p<0.01). 6. Relationship between work style (fixed vs. shift) and sleep: Shift workers tend to have poorer sleep deviation scores This survey also looked into the relationship between work style and sleep. The results showed that people on a shift work schedule slept 6 hours and 48 minutes, which is not particularly short compared to those on a fixed schedule, but their sleep deviation score was 46.6, which was significantly worse than those on a fixed schedule. To achieve good sleep, it is important to keep your sleep time as constant as possible every day. If it's 10 p.m., then 10 p.m. every day; if it's 3 a.m., then 3 a.m. every day. Having a fixed bedtime creates an optimal rhythm for falling asleep, making it easier to fall asleep and get a deep sleep, but in the case of shift work, it is difficult to fix it, and as a result, it is thought that the sleep deviation score tends to be worse. This survey also found that about 10% of all Japanese employed people who responded to the survey are working in shifts. Shift work cannot be recommended simply from the perspective of whether it is good or bad for sleep, but it is also true that modern society cannot be supported without shift work. Many companies introduce shift work for economic efficiency in order to provide 24-hour services and operate factories 24 hours a day, and it is thought that the work system is often decided with economic priority. In addition, police stations, fire stations, private security companies, and other jobs that maintain public safety and social infrastructure have no choice but to respond 24 hours a day. While it's not a perfect solution, it's important to move shifts back rather than forward to make things easier for shift workers. For example, in the case of a hospital nurse working in a three-shift system with day shifts, night shifts, and night shifts, the order would be day shift → night shift → night shift, rather than night shift → night shift → day shift. It is said that shifting the shifts later makes it easier for nurses to adapt, reduces sleepiness and productivity issues, and leads to higher satisfaction. * A t-test was conducted on the sleep duration and quality of sleep between the fixed-time and shift-time groups (**: p<0.01). ■Sleep Standard Deviation® Survey Results Page https://brain-sleep.com/service/sleepdeviationvalue/research2023/ Brain Sleep can provide various information regarding this survey. *When using the content of this survey, please be sure to cite "Sleep Standard Deviation® 2023 Brain Sleep Survey" as the source. ■What is Sleep Standard Deviation®? When assessing sleep, attention is often focused on simple quantitative data such as sleep time, but Brain Sleep believes it is important to assess sleep from a more multifaceted and comprehensive perspective. Therefore, we created a set of questions to quantify the subjective assessment of sleep from a wide range of perspectives, including subjective symptoms and sleep habits, and further quantified it as a "deviation score" familiar to Japanese people, building a system that makes it possible to grasp the relative sleep state of the Japanese population as a whole. This is "Sleep Deviation Score®". Currently, with NTT East Japan as our innovation partner, we are developing a corporate health management service called "Sleep Standard Deviation for Biz." This service visualizes employees' "engagement" with the company from their "sleep" and compares it with the national sleep standard deviation, allowing you to become aware of issues that may not have surfaced within your own company and improve presenteeism. [Survey Overview] Survey method: Web survey Target area: Nationwide Eligibility: Male and female Sample size: n=10,000ss Survey period: January 2023 *When comparing sleep deviation values and scores between groups, one-way analysis of variance or t-tests were performed, and differences with a significance level of 5% or less were determined to be statistically significant and are reported here. *This survey has changed some subjects and survey items from last year.
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