Background To stop the spread of the new coronavirus disease in 2019 (COVID-19), many countries had completely locked down. This lockdown restricted the everyday life of the affected residents and changed their mobility pattern, but its effects on sleep pattern were largely unknown. Methods Here, utilizing one of the largest crowdsourced database (Sleep as Android), we analyzed the sleep pattern of 25 217 users with 1 352 513 sleep records between 1 January and 29 April 2020 in the US and 16 European countries (Germany, UK, Spain, France, Italy, The Netherlands, Belgium, Hungary, Denmark, Finland, Norway, Czech, Sweden, Austria, Poland and Switzerland) with more than 100 records in all days of 2020. Results During the COVID-19 pandemic, the sleeping pattern before and after the country-level lockdown largely differed. The subjects increased their sleep duration by an average of 11.3 to 18.6 min on weekday nights, except Denmark (4.9 min) and Finland (7.1 min). In addition, subjects form all 16 European countries delayed their sleep onset from 10.7 min (Sweden) to 29.6 min (Austria). Conclusion During the COVID-19 pandemic, residents in the US and 16 European countries delayed their bedtime and slept longer than usual.

The Chinese Government quarantined Wuhan on 23 January 2020 and thereafter the Hubei province, affecting a total of 59 million citizens, to cease the spread of the coronavirus disease in 2019 . The effects of this lockdown on the psychological and mental health of both the affected and unaffected Chinese are largely unknown currently. We utilized one of the largest crowdsourced databases (Sleep as Android) that consisted of 15,681 sleep records from 563 users in China to estimate the change in the sleep pattern of Chinese users during the span of 30 December 2019 to 8 March 2020 with reference to 64,378 sleep records of 1,628 users for the same calendar period of years 2011-2019. The sleep pattern in China changed drastically after 23 January 2020 when the law of quarantine and suspension of Wuhan became effective. The two major findings are: (1) Chinese people increased their sleep duration by an average of 20 min and delayed their sleep onset by an average of 30 min at weekdays, while they maintained a similar sleep duration at weekends, and (2) larger changes were found in several subgroups, including those in Wuhan (80 sleep records from 3 users), female subjects, and those aged ≤ 24 years. Overall, Chinese people slept later and longer than usual during the COVID-19 pandemic quarantine.

This study examined the sleep pattern of Hong Kong residents during the anti-extradition bill controversy from June to December of 2019. We used crowdsourced sleep data of 5,442,005 sleep records from 76,600 users (15,693 records from 274 users who were Hong Kong residents at the time of the study, mean age 33.3, SD 9.6). A total of 123 participants (44.9%) provided at least 30 days of data. We compared these sleep parameters in Year 2019 to their expected values. The expected value of these variables was computed using linear regression, controlling for time zone, the month of the record, and the day of the record (S/M/T/W/T/F/S). At the nights of major protest events, habitual sleep duration of the participants was reduced by 8 to 23 min and delayed their sleep onset by at most 34 min. Date-specific analysis (12th June, 21st July, 31st August, 1st October, 12th November, 23rd November, and 24th November) revealed Hong Kong residents changed their sleep pattern according to the timeline of the protests.