Changes in sleep duration during the long-lasting COVID-19 pandemic: individual and regional disparities

The adequate quality and quantity of sleep are related to maintaining the immune system and mental well-being; therefore, it is necessary to evaluate sleep duration during COVID-19. This study aimed to investigate the changes in sleep duration during the long-lasting COVID-19 period (2020 and 2021) in South Korea, and to examine the individual and regional disparities. The study population comprised 1,143,460 adults aged ≥19 years who participated in the 2017– 2021 Korea Community Health Survey excluding those who did not respond to the daily sleep duration questionnaire. For statistical analysis, we first conducted a multiple regression model for 229 districts to estimate the district-specific changes in sleep duration. We then applied a meta-analysis to pool the 229 estimates and a meta-regression to examine the association between changes in sleep duration and regional characteristics. The sleep duration increased by 9.66 (95% CI: 8.53, 10.80) min in 2020 and 3.66 (95% CI: 2.09, 5.22) min in 2021 compared to the pre-pandemic period (2017–2019). The increase was more prominent in males, younger adults, employed individuals, and those with a high socioeconomic status compared to the general population. Communities with a higher proportion of apartments, lower normalized difference vegetation index in summer, and lower practice rate of moderate exercise were associated with a higher increase in sleep duration during the pandemic. The sleep duration increased during the COVID-19 pandemic, and the increase decreased as the COVID-19 lasted longer. The findings of our study highlight that preventive measures to manage sleep health during a pandemic should be framed in consideration of individual and regional characteristics. ### Competing Interest Statement The authors have declared no competing interest. ### Funding Statement Yes ### Author Declarations I confirm all relevant ethical guidelines have been followed, and any necessary IRB and/or ethics committee approvals have been obtained. Yes The details of the IRB/oversight body that provided approval or exemption for the research described are given below: Informed consent was not required because publicly available and de-identified KCHS data was used. I confirm that all necessary patient/participant consent has been obtained and the appropriate institutional forms have been archived, and that any patient/participant/sample identifiers included were not known to anyone (e.g., hospital staff, patients or participants themselves) outside the research group so cannot be used to identify individuals. Yes I understand that all clinical trials and any other prospective interventional studies must be registered with an ICMJE-approved registry, such as ClinicalTrials.gov. I confirm that any such study reported in the manuscript has been registered and the trial registration ID is provided (note: if posting a prospective study registered retrospectively, please provide a statement in the trial ID field explaining why the study was not registered in advance). Yes I have followed all appropriate research reporting guidelines, such as any relevant EQUATOR Network research reporting checklist(s) and other pertinent material, if applicable. Yes The database of KCHS and community health outcomes and determinants are publicly available from the Korea Centers for Disease Control and Prevention (https://chs.kdca.go.kr/chs/index.do) in Korean. Data of local tax are accessible from the Korea Statistics Office (https://kosis.kr/eng/statisticsList/statisticsListIndex.do?menuId=M\_01\_01&vwcd=MT\_ETITLE&parmTabId=M\_01\_01#R\_18.2). Data of NDVI are available from MODIS (https://modis.gsfc.nasa.gov/data/dataprod/mod13.php).