title: Sleep problems: a predictor of long-term work disability? A four-year prospective study.
abstract: OBJECTIVE
  This study investigates sleep problems as a predictor of long-term work disability.
  
  
  METHODS
  Data from a community-based four-year prospective study were used. In 1990, all inhabitants of the municipality of Ullensaker, Norway, belonging to six age cohorts (20-22, 30-32, 40-42, 50-52, 60-62, and 70-72 years), were mailed a questionnaire. Of the 1,788 responders who were working and not older than 62 years, 1,426 (80%) returned a second questionnaire four years later (1994).
  
  
  RESULTS
  Reporting mediocre or poor sleep (in contrast to good) in 1990 was significantly related to long-term work disability (> 8 weeks) during the previous 12 months in 1994 (odds ratio = 2.16; 95% confidence interval = 1.26-3.72), after adjustments for age, gender, civil status, body mass index, emotional symptoms, musculoskeletal pain, self-evaluated health, smoking, physical exercise, job satisfaction, and work characteristics.
  
  
  CONCLUSIONS
  The study indicates that sleep problems are a predictor of long-term work disability.
authors.affiliation: Department of General Practice and Community Medicine, University of Oslo, Norway. w.b.eriksen@samfunnsmed.uio.no
authors.forename: W
authors.initials: W
authors.lastname: Eriksen
authors.forename: B
authors.initials: B
authors.lastname: Natvig
authors.forename: D
authors.initials: D
authors.lastname: Bruusgaard
mesh_terms: D000328:Adult; D000368:Aged; D016009:Chi-Square Distribution; D006233:Persons with Disabilities / Q000523:psychology / Q000706:statistics & numerical data*; D004651:Employment / Q000523:psychology / Q000706:statistics & numerical data*; D005260:Female; D015438:Health Behavior; D006304:Health Status; D006801:Humans; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D009664:Norway / Q000453:epidemiology; D015995:Prevalence; D011446:Prospective Studies; D012307:Risk Factors; D012424:Rural Population; D012893:Sleep Wake Disorders / Q000150:complications* / Q000453:epidemiology*; D011795:Surveys and Questionnaires