New overtime limits for physicians aimed at improving sleep and mental health

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.