Insomnia, sleep disruption, and job burnout were linked to higher odds of COVID-19 among physicians and other healthcare workers frequently exposed to SARS-CoV-2, a survey of nearly 2,900 clinicians showed.
Clinicians in high-risk jobs who had three sleep problems — difficulty sleeping at night, poor sleep continuity, and frequent sleeping pill use — had almost twice as much risk for COVID-19 than those with no sleep problems (OR 1.88, 95% CI 1.17-3.01, P trend=0.22), reported Sara Seidelmann, MD, PhD, of Stamford Hospital in Connecticut, and co-authors.
Each 1-hour increase in sleep at night was tied to 12% lower odds of COVID-19 (OR 0.88, 95% CI 0.81-0.96, P=0.003) after adjusting for confounders, the researchers wrote in BMJ Nutrition, Prevention, and Health.
Clinicians who said they experienced burnout at work every day also had a higher risk of COVID-19 infection (OR 2.60, 95% CI 1.57-4.31, P trend=0.001), longer disease duration (OR 2.98, 95% CI 1.10-8.05, P trend=0.02), and greater COVID-19 severity (OR 3.26, 95% CI 1.25-8.48, P trend=0.02) compared with those who reported no job burnout.
“While we know that [lack of] personal protective equipment, hand washing, and social distancing are significant risk factors for COVID-19, this study highlights the importance of less studied, non-hygiene-related factors, which may independently contribute to risk for disease development,” Seidelmann said.
“This work encourages a holistic approach to health, including sleep optimization and job stress reduction, to protect our healthcare workers from this and future pandemics,” she told MedPage Today.
“Sleep is essential for optimal immune function,” noted Michael Irwin, MD, of the UCLA Geffen School of Medicine in Los Angeles, who wasn’t involved in the study. “During sleep, the immune system is restored and primed in ways that allow immune cells to recognize and respond robustly to infectious challenges during the day. In contrast, short sleep duration or poor sleep quality impairs the ability to resist an infectious challenge — for example, an experimental inoculation with a standard dose of virus — and also blunts the immunogenicity of vaccinations.”
“Moreover, sleep disturbance may be a two-edged sword for COVID infection,” Irwin told MedPage Today. “Sleep disturbance not only decreases resistance to viral infection, but also triggers the transcriptional pathways that induce the inflammatory cascade leading to exaggerated production of systemic markers of inflammation such as C-reactive protein, interleukin-6, and tumor necrosis factor, which together may increase the risk of severity of COVID infections.“
The findings were based on an online poll of clinicians frequently exposed to COVID-19 in the U.S., Spain, Italy, France, Germany, and the U.K. from July 17 to Sept. 25, 2020. Survey questions asked about the number of hours clinicians slept at night and during the day in the year preceding the pandemic, sleep problems or job burnout prior to the pandemic, and workplace exposure to COVID-19.
Nearly all participants — 95% — were physicians, most commonly emergency medicine, internal medicine, and pulmonology specialists. They had an average age of 48 and 72% were men; more than a third (36.8%) were from the U.S. Respondents averaged 6.7 hours of sleep at night and 0.9 hours of daytime napping before the pandemic. Most said job burnout was rare, occurring less than once a month to a few times a month.
Of 2,884 exposed healthcare workers who participated in the survey, 568 had COVID-19 based on self-reported symptoms or positive swab tests. Compared with 2,316 controls, the 568 respondents with COVID-19 were slightly younger, more likely to be physicians, and more likely to practice internal medicine. They were more likely to report fewer sleep hours at night, slightly more daytime napping hours, and have one or more sleep problems.
A significant dose-response relationship between the frequency of job burnout and COVID-19 emerged. Daytime napping was tied to 6% higher odds of SARS-CoV-2 infection, but that relationship varied by country with a non-significant inverse association in Spain. All associations remained significant after adjusting for frequency of COVID-19 exposures.
This study assessed sleep before the pandemic, but habits have changed overall since the advent of COVID-19, noted Rebecca Robillard, PhD, of the University of Ottawa in Canada, who wasn’t part of the study. “While the proportion of people suffering from insomnia reached over 50% during the pandemic, sleep is being affected in many different ways in various subgroups of the population,” Robillard told MedPage Today.
“Many people are going to bed later, but some are not able to sleep in to catch up in the morning, which leads to curtailed sleep,” she pointed out. “This is concerning because we know that both delays in sleep schedules and reductions in sleep durations are linked to less favorable health outcomes, including how our body can recover from illnesses.”
The study had several limitations, Seidelmann and co-authors noted. Participants self-reported their exposure, outcome, and covariates; recall bias may have led to inaccurate reports about sleep and nap hours. The researchers did not define the timeframe of the COVID-19 pandemic. Clinicians with the most severe COVID-19 cases may have been too ill to take the survey, and unknown confounders may have influenced results.
This study was funded by Survey Healthcare Globus. Researchers reported grants from the NIH.