Real time data collected during the 2024 Noto Peninsula earthquake response show that unclear tasks and command structures, and lack of meal- and rest breaks increased self-reported fatigue among disaster responders.
The frequency of natural disasters is increasing, and hence disaster responders are called on more than ever before. During disaster response, the focus of health and well-being is typically on the residents of the disaster-impacted zones. The health and well-being of disaster responders have been given less importance despite the vital role they play; however, managing it is a critical issue to increase the success of recovery efforts.
A research team led by Hiroshima University has used real-time data collected from disaster responders during the 2024 Noto Peninsula earthquake response. Using this data, they identified key factors associated with self-reported fatigue, identifying possibilities to improve the health and well-being of disaster responders while responding to disasters.
Their findings were published in the journal Safety and Health at Work on March 18, 2026.
During the 2024 Noto Peninsula earthquake response, the Japanese Surveillance in Post-extreme Emergencies and Disasters (J-SPEED+) app was used to monitor disaster responders’ health and well-being in real time through daily surveys. This was the first time such data was collected, presenting a unique dataset for analysis; typically, such data is collected retrospectively, once the response is complete.
The research team says that their study seeks to understand what specific factors actually drive fatigue during disaster response. When responders are fatigued, their ability to think clearly, make decisions, and provide safe care can be compromised. This can affect not only their own health but also the safety and outcomes of the people they are trying to help. In this way, fatigue becomes a broader public safety and system-level concern, rather than an individual issue.
During the 2024 Noto Peninsula earthquake response, the Health Emergency Operations Center (HEOC) of Ishikawa collected data from disaster responders via J-SPEED＋ from Jan 1 to Mar 31, 2024. The data consisted of 46 checkbox questions across eight sections: organization name, type of occupation, type of activity, problems in the work environment, symptoms, work performance, fatigue, and consultation requests. The occupations of disaster responders included doctors, nurses, logisticians, other health and welfare support staff, administrative supporters, and others; and the types of activities were HEOC, field work, and others. Fatigue was measured daily using a 10-point scale (1 = minimal and 10 = extreme), adapted from the visual analog scale for assessing fatigue developed by the Japan Society of Fatigue.
The research team statistically analyzed 15,067 records containing complete data. The disaster response was broken into two phases: Jan 1 to Feb 6 (first phase) and Feb 6 to Mar 31 (second phase). The relationship between fatigue scores and other factors was analyzed. Of the 15,067 records—representing 5,569 individuals —9,583 were collected during the first phase and 5,484 during the second phase. Occupationally, contributions to the records were mainly from logisticians (32.9%), nurses (29.6%), doctors (21.5%). Field staff contributed most of the data entries (65.8%), and HEOC staff and other responders contributed fewer entries.
The researchers found that fatigue scores had greater variability in the first phase, while the second phase had less variability. 73.7% of all fatigue scores ranged from 1 to 3 during the first phase, and this percentage was 82.3% during the second phase.
‘Unsafe work environment,’ ‘inability to take meals and breaks’ significantly associated with higher fatigue
The researchers determined that responders working in administrative support and logisticians had greater fatigue, possibly due to demanding daily unfamiliar and non-routine tasks. Additionally, responders working at an HEOC had greater fatigue due to their role in coordinating the support for medical personnel and supplies, which involves high cognitive demand and requires rapid decision-making about non-routine tasks.
Higher fatigue scores were associated with unclear tasks and commands. Previous Japanese and global studies have indicated similar associations. Specifically, after the 2011 Great East Japan Earthquake, responders performing ‘diverse tasks unlike during peacetime’ reported chronic fatigue due to ill-defined roles.
They also showed that ‘unsafe work environment’ and ‘inability to take meals and breaks’ were significantly associated with higher fatigue. The inclement weather and lack of rest during the earthquake response likely intensified the physical and psychological burdens on responders. Finally, insecure communication can lead to responder fatigue, especially in the early phase of disasters.
“Our most striking finding was that problems in coordination or command systems significantly increased fatigue,” explains Tatsuhiro Nagata, researcher at the Graduate School of Biomedical and Health Sciences , and first author of the paper. “This means that confusion, unclear instructions, or poor management can exhaust responders almost as much as physical work itself. Moreover, the impact of missing breaks and meals was stronger than many individual characteristics such as role or experience. Put simply, ddisaster responders are like the engine of an emergency response — [and] if the system does not provide fuel (rest, food, coordination), even the strongest engine will fail.”
Nagata continues, “Responders can remain healthier, safer, and more effective in their roles by improving planning, ensuring regular breaks, and strengthening coordination and management systems.”
The research team proposed policy and practical implications to manage the health and well-being of disaster responders. First, it is essential to establish structured fatigue management protocols, such as scheduled rest, meal breaks, and access to health support. There is also a need to strengthen command clarity and role definition through regular preparedness exercises and simulation-based training. Finally, maximizing the utility of the J-SPEED + Health app is essential. Clear user guidelines and motivation strategies should be provided to encourage consistent real-time health reporting.
Their ultimate goal is to create a disaster response system where responders can work safely, sustainably, and effectively — so they can continue to care for others without compromising their own health. Rather than simply recognizing that responders become fatigued, the goal is to actively redesign the system to prevent unnecessary exhaustion.
Yamato Sasaki, Odgerel Chimed-Ochir, Inn Kynn Khaing, Hanako Murayama, Akihiro Taji, Noriyuki Shiroma, Ami Fukunaga, Yui Yumiya, and Tatsuhiko Kubo at Hiroshima University; and Seiichiro Tateishi, Nahoko Enokida, Koji Mori, and Yoshihisa Fujino at the University of Occupational and Environmental Health contributed to the study. Odgerel Chimed-Ochir was the corresponding author of the study.
The study was supported by Japan Science and Technology Agency (JST) SPRING (JPMJSP2132).
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About Hiroshima University
Since its foundation in 1949, Hiroshima University has striven to become one of the most prominent and comprehensive universities in Japan for the promotion and development of scholarship and education. Consisting of 12 schools for undergraduate level and 5 graduate schools, ranging from natural sciences to humanities and social sciences, the university has grown into one of the most distinguished comprehensive research universities in Japan. English website: https://www.hiroshima-u.ac.jp/en
Safety and Health at Work
Data/statistical analysis
People
Key Contributors to Fatigue in Disaster Responders: Analysis of the 2024 Noto Peninsula Earthquake
18-Mar-2026