Open Access Research article

National survey of the association of depressive symptoms with the number of off duty and on-call, and sleep hours among physicians working in Japanese hospitals: a cross sectional study

Koji Wada12*, Toru Yoshikawa13, Takahisa Goto14, Aizan Hirai15, Eisuke Matsushima16, Yoshifumi Nakashima17, Rie Akaho18, Michiko Kido19 and Takashi Hosaka110

Author affiliations

1 The committee for Physicians' Health, the Japan Medical Association, Japan

2 Department of Preventive Medicine and Public Health Kitasato University School of Medicine, Sagamihara, Japan

3 Institute for Science of Labour, Kawasaki, Japan

4 Department of Anesthesiology and Critical Care Medicine Yokohama City University Graduate School of Medicine, Yokohama, Japan

5 Chiba prefectural Togane Hospital, Togane, Japan

6 Section of Liaison Psychiatry and Palliative Medicine, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo, Japan

7 Department of psychiatry, Mitsui Memorial Hospital, Tokyo, Japan

8 Department of Psychiatry, Tokyo Metropolitan Cancer and Infectious disease Center Komagome Hospital, Tokyo, Japan

9 Departments of Obstetrics & Gynecology, the Japanese Red Cross Medical Center, Tokyo, Japan

10 Tokai University School of Medicine, Tokyo Hospital, Tokyo, Japan

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Citation and License

BMC Public Health 2010, 10:127  doi:10.1186/1471-2458-10-127

Published: 12 March 2010



Physicians' mental health may be adversely affected by the number of days of work and time spent on-call, and improved by sleep and days-off. The aim of this study was to determine the associations of depressive symptoms with taking days of off duty, hours of sleep, and the number of days of on-call and overnight work among physicians working in Japanese hospitals.


A cross-sectional study as a national survey was conducted by mail. The study population was 10,000 randomly selected physicians working in hospitals who were also members of the Japan Medical Association (response rate 40.5%). Self-reported anonymous questionnaire was sent to assess the number of days off-duty, overnight work, and on-calls, and the average number of sleep hours on days not working overnight in the previous one month. Depressive state was determined by the Japanese version of the Quick Inventory of Depressive Symptomatology. Logistic regression analysis was used to explore the associations between depressive symptoms and the studied variables.


Among the respondents, 8.3% of men and 10.5% of women were determined to be depressed. For both men and women, depressive state was associated with having no off-duty days and averaging less than 5 hours of sleep on days not doing overnight work. Depressive state was positively associated with being on-call more than 5 days per month for men, and more than 8 days per month for women, and was negatively associated with being off-duty more than 8 days per month for men.


Some physicians need some support to maintain their mental health. Physicians who do not take enough days-off, who reduced sleep hours, and who have certain number of days on-calls may develop depressive symptoms.