Abstract
BACKGROUND: While the adverse effects of shift work on non-communicable diseases are widely recognized, research on its impact on infectious diseases is limited. We aim to investigate the association of shift work with hospital-treated infections through a large cohort, and to explore the mediating role of lifestyles in this association. METHODS: This cohort study included employed workers from the UK Biobank. Work status was self-reported at baseline (2006–2010). A total of 866 types of hospital-treated infectious diseases were identified through hospital inpatient records. Lifestyle factors included smoking, alcohol consumption, body mass index, sedentary behavior, sleep duration, diet, and physical activity. We performed Cox proportional hazards regression models to examine the association of shift work with infections, and cause mediation analyses to explore the mediating role of lifestyles. RESULTS: Of 266,450 employed workers, 45,406 (17.04%) reported working shifts. During a median follow-up of 12.47 years (IQR 11.55–13.25), 40,684 workers (15.27%) developed severe infections that required hospital treatment. Shift work was associated with a higher risk of infectious diseases (HR 1.10, 95% CI 1.07–1.13), and comparable risks were observed across different shift frequencies (sometimes: HR 1.09, 95% CI 1.05–1.13; usually/always: HR 1.10, 95% CI 1.07–1.14). CONCLUSIONS: In this cohort study, shift work was associated with higher risks of hospital-treated infections, with lifestyle variables mediating this association. It is recommended to consider shift work as an occupational hazard and implement individual-level and organizational-level interventions to mitigate vulnerability to infectious diseases. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s12879-026-12979-3.