title: Development of the chronic fatigue syndrome in severely fatigued employees: predictors of outcome in the Maastricht cohort study.
abstract: OBJECTIVE
  To identify risk factors of the development of the chronic fatigue syndrome (CFS), the persistence or recurrence of fatigue, or recovery from fatigue in a large sample of fatigued employees.
  
  
  METHODS
  Analyses were based on the Maastricht cohort study (MCS), a prospective population based cohort study among more than 12 000 employees. Multiple regression models were used to identify predictors of CFS-like caseness (meeting research criteria for CFS), non-CFS fatigue caseness, or no fatigue caseness.
  
  
  METHODS
  The working population in the Netherlands.
  
  
  METHODS
  1143 employees with medically unexplained fatigue were followed up prospectively for 44 months.
  
  
  RESULTS
  At 44 month follow up, 8% of the employees were CFS-like cases (none of who reported to have received a CFS diagnosis), 40% were non-CFS fatigue cases, and 52% were no longer fatigue cases. Factors that predicted CFS-like caseness compared with non-CFS fatigue caseness were high age, exhaustion, female sex, low education, and visits to the general practitioner. Factors that predicted CFS-like caseness compared with no fatigue caseness were fatigue, exhaustion, low education, visits to the GP and occupational physician, and bad self rated health. Factors that predicted non-CFS fatigue caseness compared with no fatigue caseness were fatigue, low self perceived activity, exhaustion, anxious mood, and bad self rated health.
  
  
  CONCLUSIONS
  Unexplained fatigue among employees in some instances is a precursor of the development of CFS. The prognostic role of self rated health suggests that prevention and treatment of chronic fatigue should be aimed at changing the perception of health or illness. Less clear is the role of health care seeking or receiving a CFS diagnosis.
authors.affiliation: Department of Epidemiology, Maastricht University, PO Box 616, 6200 MD Maastricht, Netherlands. m.huibers@dmkep.unimaas.nl
authors.forename: Marcus J H
authors.initials: MJ
authors.lastname: Huibers
authors.forename: I Jmert
authors.initials: IJ
authors.lastname: Kant
authors.forename: J André
authors.initials: JA
authors.lastname: Knottnerus
authors.forename: Gijs
authors.initials: G
authors.lastname: Bleijenberg
authors.forename: Gerard M H
authors.initials: GM
authors.lastname: Swaen
authors.forename: Stanislav V
authors.initials: SV
authors.lastname: Kasl
mesh_terms: D000328:Adult; D004812:Epidemiologic Methods; D005221:Fatigue / Q000175:diagnosis* / Q000453:epidemiology; D015673:Fatigue Syndrome, Chronic / Q000175:diagnosis / Q000453:epidemiology / Q000209:etiology*; D005260:Female; D006305:Health Status Indicators; D006801:Humans; D008297:Male; D008875:Middle Aged; D009426:Netherlands / Q000453:epidemiology; D009784:Occupational Diseases / Q000175:diagnosis* / Q000453:epidemiology; D010342:Patient Acceptance of Health Care / Q000706:statistics & numerical data; D011379:Prognosis; D012720:Severity of Illness Index