Global Differences In Weekly Sleep Variability And Sleep Extension

Those who live in Asia are known to report worse sleep than their counterparts in North America and Europe. This study set out to determine if the reports are true by analyzing 50 million nights of anonymized sleep data that was contributed by over 220,000 users of the Oura Ring sleep tracker from across 35 countries. The majority of the users were working adults between the ages of 30-55 years old. Sleep data was gathered from multiple nights across a year, with each user contributing 242 nights of data on average to conduct a comprehensive analysis of sleep measures for each user. To assess the impact of the working week on sleep patterns the researchers analyzed weekday and weekend sleep separately. 

According to the researchers, their findings showed that people in Asia have shorter sleep, display higher variability in weekday sleep timing and duration, have lower sleep efficiency, and also fall asleep later than those living in North America, Europe, and Oceania. Other research indicates that shorter sleep duration is typically associated with higher sleep efficiency because people make an effort to make the most of their sleeping opportunities, however, in this study that was not the case which could be due to many factors that result in less sleep and lower quality of sleep such as work related anxiety. 

To try and make up for lost sleep during the week, people frequently sleep longer on the weekends, this is known as weekend sleep extension. While there was a clear association between short weekday sleep and longer weekend sleep extensions in this study that suggested people caught up on their sleep during the weekend, even after accounting for this, those living in Asia had the shortest weekend sleep extensions. Additionally, there are a variety of socio-cultural factors that affect sleep patterns, as these play fundamental roles in our lives and work these factors are also some of the most influential factors that affect how we sleep. 

"In Europe, weekends are generally considered time for relaxation, and engaging in social activities with friends and family. In Asia, however, people may use the weekends to catch up on work, do the things they didn't have time for during the week or attend to more family responsibilities. We think that longer working hours and the difference in work culture in Asia means that people don't catch up on sleep as much at the weekends, but try to catch up whenever they have the opportunity over the course of the week,” said Dr. Adrian Willoughby, Senior Research Fellow at NUS Medicine's Centre for Sleep and Cognition.

"Sleep is a significant issue to address, especially for people living in Asia, who seem to sleep less than other global regions. Access to such a large dataset has allowed us to have unique insights into global sleep patterns. This research enables us to work towards our goal of giving customised sleep advice that considers individual sleep needs, environment factors and larger socio-cultural pressures that affect sleep. We want people to practise sleep routines that fit different contexts, but also promote health, well-being and performance,” said Prof Michael Chee, Director of the Centre for Sleep and Cognition at NUS Medicine.