Sleep habits and burnout are tied to infectious disease risks, and new evidence shows that healthcare workers who manage to get a long nights’ sleep are less likely to contract COVID-19. Worker burnout, meanwhile, has the opposite effect.

That’s according to a web-based survey of workers with a high frequency of COVID-19 exposure. The study ranged across six countries, including the United States. Participants answered questions about demographics, number of sleep hours at night, daytime napping hours, sleep problems, burnout from work, and COVID-19 exposures. 

Data analysis showed that respondents with one hour longer sleep duration at night had 12% lower odds of contracting COVID-19. Compared with having no sleep problems, having three sleep problems was associated with 88% greater odds of COVID-19. What’s more, workers who reported that they felt burned out every day were more likely to become infected and have longer symptom duration and severity when compared with those who reported no burnout.

The associations remained significant no matter the frequency of exposure to COVID-19, added lead author Sara Seidelmann, M.D., of the Columbia University College of Physicians & Surgeons.

“Our results highlight the importance of healthcare professionals’ well-being during the pandemic,” Seidelmann and colleagues wrote. “Awareness of these risk factors in healthcare workers will be helpful in maintaining a healthy and productive workforce.”

The study was published Monday in the BMJ.