Shift workers face a 23% higher incidence rate of influenza-like illness and acute respiratory infection episodes compared to non-shift workers, according to a prospective cohort study published in the Scandinavian Journal of Work, Environment & Health. Researchers tracked 396 hospital employees to evaluate whether sleep, physical activity, and diet explain why irregular hours leave healthcare staff more vulnerable to falling sick.
Study Design Reveals 23% Higher Infection Rate Among Hospital Employees
Hospital employees who had either spent at least six months on rotating or night schedules or had avoided both shift types for the same duration were evaluated in this prospective cohort study. Researchers at baseline assessed sleep duration and physical activity using accelerometers and diaries, while participants reported sleep quality and recorded daily food intake. Over the following six months, participants logged respiratory symptoms daily via a smartphone application, according to the findings.
On average, shift workers experienced 3.5 acute respiratory infection or influenza-like illness episodes, whereas non-shift workers recorded 2.9 such instances, according to the data. After adjusting for age, gender, occupation, influenza vaccination status, and perceived general health, investigators found that shift workers maintained a 23% higher incidence rate of respiratory infection episodes than their non-shift peers.
Sleep Quality Emerges as Key Mediator Over Duration and Diet
When researchers incorporated sleep, physical activity, and dietary measures into their statistical model, the infection rate difference fell to 15% and lost statistical significance. Among these factors, poor sleep quality produced the largest indirect effect in the analysis, according to the study data.
Did you know? Shift workers in the study had more than three times the odds of reporting poor sleep quality compared with non-shift workers, which created a pathway leading to a 29% higher incidence rate of respiratory infection episodes.
Perceived sleep quality appeared substantially more important than objectively measured sleep duration. While shift workers experienced frequent short sleep, neither short nor long sleep duration significantly mediated the relationship between shift work and respiratory infections. Meanwhile, physical activity and eating patterns failed to emerge as significant mediators. Although shift workers were substantially more active at work, neither workplace nor leisure activity explained the elevated infection incidence, and daily meal or snack counts had no significant mediating effect.
Future Implications for Healthcare Workforce Health
The findings suggest that perceived sleep quality may warrant greater attention when investigating infection susceptibility among healthcare shift workers. However, the study authors emphasized that further investigations are required to replicate these findings, evaluate additional biological mechanisms, and determine whether actively improving sleep quality can successfully lower respiratory infection incidence in hospital settings.
Frequently Asked Questions
How much higher is the respiratory infection rate in shift workers?
According to the study, shift workers showed a 23% higher incidence rate of influenza-like illness and acute respiratory infection episodes than non-shift workers after adjusting for demographic and health factors.
Did sleep duration or sleep quality matter more?
Perceived sleep quality emerged as the key mediator. Shift workers had more than three times the odds of reporting poor sleep quality, creating a pathway associated with a 29% higher infection rate, whereas objective sleep duration did not significantly mediate the relationship.
Did diet and exercise explain the higher infection rates?
No. Neither physical activity nor daily eating patterns had a significant mediating effect on the association between shift work and respiratory infections.
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