title: Excessive work and risk of haemorrhagic stroke: a nationwide case-control study.
abstract: BACKGROUND
  Adverse effect of excessive work on health has been suggested previously, but it was not documented in cerebrovascular diseases.
  
  
  OBJECTIVE
  The authors investigated whether excessive working conditions would associate with increased risk of haemorrhagic stroke.
  
  
  METHODS
  A nationwide matched case-control study database, which contains 940 cases of incident haemorrhagic stroke (498 intracerebral haemorrhages and 442 sub-arachnoid haemorrhages) with 1880 gender- and age- (± 5-year) matched controls, was analysed. Work-related information based on the regular job situation, including type of occupation, regular working time, duration of strenuous activity during regular work and shift work, was gathered through face-to-face interviews. Conditional logistic regression analyses were used for the multivariable analyses.
  
  
  RESULTS
  Compared with white-collar workers, blue-collar workers had a higher risk for haemorrhagic stroke (odds ratio, 1.33 [95% confidence interval, 1.06-1.66]). Longer regular working time was associated with increased risk of haemorrhagic stroke [odds ratio, 1.38 (95% confidence interval, 1.05-1.81) for 8-12 h/day; odds ratio, 1.95 (95% confidence interval, 1.33-2.86) for ≥ 13 h/day; compared with ≤ 4 h/day]. Exposure to ≥ 8 h/week of strenuous activity also associated haemorrhagic stroke risk [odds ratio, 1.61 (95% confidence interval, 1.26-2.05); compared with no strenuous activity]. Shift work was not associated with haemorrhagic stroke (P = 0.98). Positive associations between working condition indices and haemorrhagic stroke risk were consistent regardless of haemorrhagic stroke sub-types and current employment status.
  
  
  CONCLUSIONS
  Blue-collar occupation, longer regular working time and extended duration of strenuous activity during work may relate to an increased risk of haemorrhagic stroke.
authors.affiliation: Department of Neurology, Seoul National University Bundang Hospital, Seongnam-si, Gyunggi-do, Republic of Korea; Department of Neurology, Clinical Research Centre for Stroke, Seoul National University Hospital, Seoul, Republic of Korea.
authors.forename: Beom Joon
authors.initials: BJ
authors.lastname: Kim
authors.forename: Seung-Hoon
authors.initials: SH
authors.lastname: Lee
authors.forename: Wi-Sun
authors.initials: WS
authors.lastname: Ryu
authors.forename: Chi Kyung
authors.initials: CK
authors.lastname: Kim
authors.forename: Jong-Won
authors.initials: JW
authors.lastname: Chung
authors.forename: Dohoung
authors.initials: D
authors.lastname: Kim
authors.forename: Hong-Kyun
authors.initials: HK
authors.lastname: Park
authors.forename: Hee-Joon
authors.initials: HJ
authors.lastname: Bae
authors.forename: Byung-Joo
authors.initials: BJ
authors.lastname: Park
authors.forename: Byung-Woo
authors.initials: BW
authors.lastname: Yoon
mesh_terms: D016022:Case-Control Studies; D004522:Educational Status; D005260:Female; D006801:Humans; D020300:Intracranial Hemorrhages / Q000453:epidemiology / Q000209:etiology*; D008297:Male; D008875:Middle Aged; D009784:Occupational Diseases / Q000453:epidemiology / Q000209:etiology*; D011446:Prospective Studies; D056910:Republic of Korea / Q000453:epidemiology; D012307:Risk Factors; D012923:Social Class; D020521:Stroke / Q000453:epidemiology / Q000209:etiology*; D014940:Work Schedule Tolerance / Q000502:physiology*