Shift workers are at increased risk of severe COVID-19 compared with day workers: Results from the international COVID sleep study (ICOSS) of 7141 workers

ABSTRACT

The present study had two main aims. First, to investigate whether shift/night workers had a higher prevalence and severity of COVID-19 compared with day workers. Second, to investigate whether people regularly working in face-to-face settings during the pandemic exhibited a higher prevalence and severity of COVID-19 compared with those having no need to be in close contact with others at work. Data consisted of 7141 workers from 15 countries and four continents who participated in the International COVID Sleep Study-II (ICOSS-II) between May and December 2021. The associations between work status and a positive COVID-19 test and several indications of disease severity were tested with chi-square tests and logistic regressions adjusted for relevant confounders. In addition, statistical analyses were conducted for the associations between face-to-face work and COVID-19 status. Results showed that shift/night work was not associated with an increased risk of COVID-19 compared to day work. Still, shift/night workers reported higher odds for moderate to life-threatening COVID-19 (adjusted odds ratio (aOR) = 2.71, 95%-confidence interval = 1.23–5.95) and need for hospital care (aOR = 5.66, 1.89–16.95). Face-to-face work was associated with an increased risk of COVID-19 (aOR = 1.55, 1.12–2.14) but not with higher disease severity. In conclusion, shift/night work was not associated with an increased risk of COVID-19, but when infected, shift/night workers reported more severe disease. Impaired sleep and circadian disruption commonly seen among shift/night workers may be mediating factors. Working face-to-face increased the risk of COVID-19, likely due to increased exposure to the virus. However, face-to-face work was not associated with increased disease severity.

KEYWORDS:

• Coronavirus
• SARS-CoV-2
• night work
• shift work
• face-to-face work

Acknowledgements

This study did not receive any specific funding. We acknowledge Thomas Penzel (Germany), Juliana Yordanova (Bulgaria) and Yuichi Inoue (Japan) for being instrumental in providing data to this study.

Disclosure statement

Dr. Bjorvatn reports that he has served as consultant for F. Hoffmann-La Roche Ltd and Cura of Sweden, and received honoraria for lectures from Sanofi-Aventis and AGB-Pharma AB. Dr. Chung reports grants from Ontario Ministry of Health Innovation Grant, grants from ResMed Foundation and University Health Network Foundation, and consultation fees from Takeda Pharma, outside the submitted work. Dr. Espie reports grants from the Wellcome Trust and NIHR (HTA) and is a co-founder and a shareholder in Big Health, outside of the submitted work. Dr. Holzinger reports grants from the City of Vienna, Cultural Department of the City of Vienna. Dr. De Gennaro reports consulting fees from Idorsia. Dr Landtblom reports personal fees from Takeda, Jazz Pharmaceuticals and UCB, as well as a research grant from Aoporphan drugs. Dr. Matsui reports personal fees from Eisai, Meiji Seika Pharma, Mochida, MSD, Otsuka Pharmaceutical, and Yoshitomi Pharmaceutical, outside the submitted work; Dr. Plazzi reports reseach grant from Italian Institute of Health and participated in advisor board with Bioprojet, Jazz Pharmaceuticals, Takeda, Idorsia, Orexia; Dr. Morin reports research grants from the Canadian Institutes for Health Research, Eisai, Idorsia, and Lallemand Health; consulting fees from Eisai, Idorsia, Pear Therapeutics and Sunovion; and royalties from Mapi Research Trust, all outside the submitted work. Dr. Partinen reports personal fees and other from Bioprojet, other from Jazz Pharmaceuticals, personal fees from UCB Pharma, personal fees from GSK, personal fees from Takeda, personal fees and other from MSD, personal fees from Orion, and personal fees and other from Umecrine. Dr. Wing reports personal fees for delivering a lecture-Eisai Co. Ltd and personal fees from Sponsorship from Lundbeck HK Ltd, outside the submitted work. The other authors have no disclosure of interest.

Data availability statement

The data that support the findings of this study are available from the corresponding author, BB, upon reasonable request.

Supplementary material

Supplemental data for this article can be accessed online at https://doi.org/10.1080/07420528.2022.2148182

Additional information

Funding

The author(s) reported there is no funding associated with the work featured in this article.