Shift work is associated with increased risk of COVID-19: Findings from the UK Biobank cohort

SummaryDespite 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.