Juntendo News

Researchers conducted a national-level survey to assess the link between sleep duration, objective alertness, and psychological health in Japanese physicians

 

Physicians often work for extended hours to provide medical care for patients, which can result in sleep loss and affect their optimal functioning. Researchers from Juntendo University have conducted a national survey and used a computer-based psychomotor vigilance test (PVT) to assess the impact of long work hours and sleep duration on alertness and the psychological health of Japanese physicians. Poor PVT performance was significantly associated with physician depression and burnout.

 

Exploring the correlation between sleep duration, alertness, and psychological health in Japanese physicians

Image caption: Responses during psychomotor vigilance test (PVT) are a reliable indicator of depression and burnout. PVT can be extended to other classes of professionals with long work hours to assess their mental health.

Image credit: Professor Hiroo Wada, and Professor Takeshi Tanigawa from Juntendo University Graduate School of Medicine, Japan, and Dr. Mathias Basner, University of Pennsylvania Perelman School of Medicine, USA

License type: Original content

Usage restrictions: You are free to share and adapt the Infographic material, but attribution is required, with a link to the news source.

 

Physicians are a vital component of the healthcare landscape and along with other medical professionals, they ensure timely diagnosis, treatment, and management of complex illnesses. They regularly work extended and overnight shifts, often at the cost of sleep. However, the long duty hours of physicians can lead to physical and mental exhaustion, resulting in negative consequences such as depression and burnout. Consequently, this can affect their level of alertness and thus the quality of patient care. To protect the health of Japanese physicians, a duty hour reform went into effect in 2024, limiting overtime to 960 hours annually with exceptions for physicians who serve rural areas and medical trainees, whose overtime was limited to 1,860 hours annually.

 

Although several studies have explored the correlation between work hours and sleep in physicians at large, studies investigating the effects of long work hours on sleep duration and alertness in Japanese physicians are scarce. To address this research gap and to investigate the benefits of the newly implemented overtime limits, a team of scientists have conducted a national-level survey to evaluate the link between sleep duration, alertness, and psychological health in 1,226 Japanese physicians. The research group consisted of Professor Hiroo Wada and Professor Takeshi Tanigawa from Juntendo University Graduate School of Medicine, Japan, along with Drs. Mathias Basner, David Dinges, and Makayla Cordoza from the University of Pennsylvania Perelman School of Medicine, USA.

 

They used standardized surveys to assess physician sleep duration as well as symptoms of burnout (Maslach Burnout Inventory) and depression (Center for Epidemiologic Studies Depression Scale). A brief Psychomotor Vigilance Test (PVT-B) was utilized to objectively assess physician alertness. Their research findings were published in the Journal of Sleep Research, on August 12 2024.

 

Explaining the motivation behind the present research, Dr. Wada says, “We believe that the PVT is a key tool to objectively assess alertness levels of essential workers, since self-reported alertness is inaccurate at identifying those with sleep debt, as shown in one of our previous studies. To establish an objective means of assessing alertness and its associations with mental and physical health of physicians who work for extended durations, we collaborated with the University of Pennsylvania, where the PVT was originally developed.”

 

The researchers found that daily sleep duration was inversely related to weekly work hours, and slower responses on the PVT were significantly associated with both short and long sleep duration. Furthermore, they discovered that additional duty hours were linked to increased severity of burnout and higher odds of being involved in an accident. Notably, attentional lapses on the PVT were also associated with increased depression and intense feelings of burnout. These findings suggest that PVT performance may be a useful marker of psychological health, but future studies will have to corroborate this finding.

 

“The stricter 960-hour annual overtime cap will likely benefit Japanese physician sleep and mental health. Future studies will need to show whether the suggested cap will be able to relevantly reduce overtime and improve sleep, alertness, and mental health in physicians, or whether an even stricter cap is necessary.” says Dr. Basner, a Professor in the Department of Psychiatry at the University of Pennsylvania Perelman School of Medicine who developed the brief version of the PVT and has used it in many different populations, including US physicians and astronauts.

 

The present study supports the use of the PVT as an objective assessment tool of physicians’ alertness, as recommended in the “Manual on Health Security Measures for Physicians Who Work Long Hours” in Japan. Dr. Tanigawa, emphasizing the real-life applications of their research work adds, “Almost doubling the overtime cap for physicians and for medical trainees who serve rural areas may make sense from an administrative perspective but makes little sense from a public health and safety perspective. The same cap should apply to all physicians regardless of the sector they work in or their career progression.”

 

This research study underscores the importance of adequate rest and appropriate sleep duration in maintaining psychological health and alertness levels in physicians. Overall, the study will contribute towards better quality-of-life of the physicians and their patients.

 

***

Reference

Authors	Hiroo Wada1, Mathias Basner2, Makayla Cordoza3, David Dinges2, and Takeshi Tanigawa1
Title of original paper	Objective alertness, rather than sleep duration, is associated with burnout and depression: a national survey of Japanese physicians
Journal	Journal of Sleep Research
DOI	10.1111/jsr.14304

***

About Professor Hiroo Wada

Hiroo Wada serves as a Professor in the Department of Public Health, Juntendo University Graduate School of Medicine, Japan.   He received MD and PhD from The University of Tokyo, Japan, and MBA from Hitotsubashi University, Japan, and pursued his higher studies at Imperial College London, UK.  He has been involved in clinical and public health research focusing on the health effect of environmental exposures, i.e. investigation of chronic obstructive pulmonary disease, and sleep health among children at school and among adults in workplace.  The latter constituted a scientific basis for physicians’ work-style reform. He has published more than 110 papers with 1,710 citations.

 

About Professor Takeshi Tanigawa

Takeshi Tanigawa is a Professor in the Department of Public Health, Juntendo University Graduate School of Medicine, Japan. His research focuses on epidemiological studies of sleep disorders, cardiovascular disease, and occupational medicine. He received his PhD from The University of Tokyo Graduate School of Medicine in 1990. Over the years, he has published 238 papers and four book chapters that have been cited more than 4,200 times. Currently, he is the chair of the department of public health, Juntendo University, and is on the board of various committees and professional bodies.

 

About Professor Mathias Basner

Dr. Mathias Basner is a Professor in the Department of Psychiatry at the University of Pennsylvania Perelman School of Medicine, Philadelphia, USA. His expertise involves sleep, and chronobiology, environmental effects on sleep and health, and astronaut behavioral health. He received his MD and PhD from the University of Bochum, Germany, and his MSc in Epidemiology from Bielefeld University, Germany. Currently, he serves as the Director of the Behavioral Regulation & Health Section and the Unit for Experimental Psychiatry, Division of Sleep and Chronobiology, Department of Psychiatry, University of Pennsylvania Perelman School of Medicine.