Fatima Y, Bucks RS, Mamun AA, Skinner I, Rosenzweig I, Leschziner G, Skinner TC. Shift work is associated with increased risk of COVID-19: Findings from the UK Biobank cohort. J Sleep Res. 2021 Mar 8:e13326. doi: 10.1111/jsr.13326. Epub ahead of print. PMID: 33686714.
Despite the strong evidence on circadian rhythm disruption in shift workers and consequent increased vulnerability for infection, longitudinal association between shift work and COVID-19 infection is unexplored. In this study, data from UK Biobank participants who were tested for COVID-19 infection (16 March to 7 September 2020) were used to explore the link between shift work and COVID-19 infection. Using the baseline occupational information, participants were categorised as non-shift workers, day shift workers, mixed shift workers and night shift workers. Multivariable regression models were used to assess the association between shift work and COVID-19 infection. Among the 18,221 participants (9.4% positive cases), 11.2% were health workers, and 16.4% were involved in shift-work-based jobs. Ethnic minorities (18%) and people in night-shift-based jobs (18.1%) had a significantly higher prevalence of COVID-19 infection than others. Adjusted logistics regression model suggest that, compared with their counterparts, people employed in a night-shift-based job were 1.85-fold (95% CI: 1.42-2.41) more likely to have COVID-19 infection. Sensitivity analysis focusing on people working in a non-healthcare setting suggests that people in shift-work-based jobs had 1.81-fold (95% CI: 1.04%-3.18%) higher odds of COVID-19 infection than their counterparts. Shift workers, particularly night shift workers, irrespective of their occupational group, seem to be at high risk of COVID-19 infection. If similar results are obtained from other studies, then it would mandate to revisit the criteria for defining high-risk groups for COVID-19 and implementing appropriate interventions to protect people in shift-based jobs.
The findings of this paper provide preliminary but strong evidence for the role of shift work in COVID‐19 infection. Thus, when we are considering risk factors for COVID‐19 and/or vulnerability for the condition, which may prompt testing, shift work might be one of the additional factors to be considered for timely intervention and management of at‐risk patients. This study is based on the most recent data from the UK Biobank and over 35% of the study participants were tested more than once; nonetheless, considering that the pandemic is still ongoing, many of the individuals who were negative at the time of the data analysis might not still be negative. The change in COVID infection status might affect the strength of the association between shift work and COVID‐19 infection. Therefore, as more data become available, an addendum to the current work will be useful in the current estimation of the impact of shift work on COVID‐19 infection risk.