title: 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.
abstract: BACKGROUND
  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.
  
  
  METHODS
  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.
  
  
  RESULTS
  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.
  
  
  CONCLUSIONS
  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.
authors.affiliation: The committee for Physicians' Health, the Japan Medical Association, Japan. kwada@med.kitasato-u.ac.jp
authors.forename: Koji
authors.initials: K
authors.lastname: Wada
authors.forename: Toru
authors.initials: T
authors.lastname: Yoshikawa
authors.forename: Takahisa
authors.initials: T
authors.lastname: Goto
authors.forename: Aizan
authors.initials: A
authors.lastname: Hirai
authors.forename: Eisuke
authors.initials: E
authors.lastname: Matsushima
authors.forename: Yoshifumi
authors.initials: Y
authors.lastname: Nakashima
authors.forename: Rie
authors.initials: R
authors.lastname: Akaho
authors.forename: Michiko
authors.initials: M
authors.lastname: Kido
authors.forename: Takashi
authors.initials: T
authors.lastname: Hosaka
mesh_terms: D000328:Adult; D039602:After-Hours Care / Q000706:statistics & numerical data; D000368:Aged; D001291:Attitude of Health Personnel; D003430:Cross-Sectional Studies; D003863:Depression / Q000453:epidemiology* / Q000209:etiology; D003866:Depressive Disorder / Q000453:epidemiology* / Q000209:etiology; D005260:Female; D006306:Health Surveys; D006761:Hospitals / Q000706:statistics & numerical data*; D006801:Humans; D007564:Japan / Q000453:epidemiology; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D009784:Occupational Diseases / Q000453:epidemiology / Q000209:etiology; D010820:Physicians / Q000523:psychology* / Q000706:statistics & numerical data; D012890:Sleep / Q000502:physiology*; D011795:Surveys and Questionnaires; D013997:Time Factors; D014940:Work Schedule Tolerance / Q000523:psychology*; D055815:Young Adult