title: Using repeated measures of sleep disturbances to predict future diagnosis-specific work disability: a cohort study.
abstract: BACKGROUND
  It is unknown whether or not measuring sleep disturbances repeatedly, rather than at only one point in time, improves prediction of work disability.
  
  
  OBJECTIVE
  o examine sleep disturbance patterns over time as a risk marker for diagnosis-specific work disability.
  
  
  METHODS
  Prospective cohort study linking repeatedly measured self-reported sleep disturbances with records of physician-certified work disability (sickness absence) from a national register. Participants responded to surveys in 2000-2002, and 2004, and were followed up for 12 mo.
  
  
  METHODS
  Public sector employees in Finland.
  
  
  METHODS
  25,639 participants (mean age 45.6 yr, 82% female).
  
  
  METHODS
  Incident diagnosis-specific sickness absence of > 9 days.
  
  
  RESULTS
  During a mean follow-up of 323 days, 4,975 employees (19%) had a new episode of sickness absence. In multivariable-adjusted models corrected for multiple testing, stable severe sleep disturbances, in comparison with no sleep disturbances, were associated with an increased risk of sickness absence due to diseases of the musculoskeletal system (hazard ratio (HR) 1.68, 95% confidence interval (CI) 1.45-1.95), and injuries and poisonings (HR 1.64, 95% CI 1.23-2.18). Increases in sleep disturbances predicted subsequent sickness absence due to mental disorders (HR 1.59, 95% CI 1.32-1.91), and diseases of the musculoskeletal system (HR 1.44, 95% CI 1.27-1.64) According to net reclassification improvement analyses, measurement of sleep disturbance patterns rather than the level of sleep disturbances at one point in time improved prediction of all-cause sickness absence by 14%, and diagnosis-specific sickness absences up to 17% (P for improvement < 0.001).
  
  
  CONCLUSIONS
  Increasing and severe chronic sleep disturbances mark an increased risk of diagnosis-specific work disability.
authors.affiliation: Unit for Psychosocial Factors, Finnish Institute of Occupational Health, Helsinki, Finland. paula.salo@ttl.fi
authors.forename: Paula
authors.initials: P
authors.lastname: Salo
authors.forename: Jussi
authors.initials: J
authors.lastname: Vahtera
authors.forename: Martica
authors.initials: M
authors.lastname: Hall
authors.forename: Naja Hulvej
authors.initials: NH
authors.lastname: Rod
authors.forename: Marianna
authors.initials: M
authors.lastname: Virtanen
authors.forename: Jaana
authors.initials: J
authors.lastname: Pentti
authors.forename: Noora
authors.initials: N
authors.lastname: Sjösten
authors.forename: Tuula
authors.initials: T
authors.lastname: Oksanen
authors.forename: Mika
authors.initials: M
authors.lastname: Kivimäki
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D015331:Cohort Studies; D004185:Disability Evaluation; D005260:Female; D005387:Finland; D006304:Health Status; D006801:Humans; D008297:Male; D008875:Middle Aged; D009784:Occupational Diseases / Q000175:diagnosis* / Q000453:epidemiology*; D011237:Predictive Value of Tests; D012307:Risk Factors; D018582:Sick Leave / Q000706:statistics & numerical data*; D012893:Sleep Wake Disorders / Q000150:complications*; D055815:Young Adult