title: Duration of employment is not a predictor of disability of cleaners: a longitudinal study.
abstract: OBJECTIVE
  Cleaning is a high-risk occupation for developing musculoskeletal disorders. Sickness absence is twice as high as in other occupations. Disability pensions for musculoskeletal disorders are twice as high in cleaners as in other employed women. However, a result from Norwegian and Danish studies shows that female cleaners do not report higher morbidity of musculoskeletal disorders than other women. The objective was to analyse whether female cleaners have a higher risk of obtaining a disability pension than women in other unskilled occupations and whether the length of employment influences the risk.
  
  
  METHODS
  The material is from the National Census in 1980 and 1990 and supplemented with disability pensioning data from the National Insurance Administration and the Population registry. Women aged 20-49, working as cleaners, seamstresses, nursing, kitchen, or shop assistants in 1980 were followed until 1990 or until receiving disability pension. Female cleaners aged 30-59 years in 1990 were categorized into two cohorts by occupation in 1980. They were followed from 1991 to 1994, to the date they died, or received disability pension. Incidence rates and incidence rate ratio for disability pension and mortality was calculated by Poisson regression. Cox regression calculated the relative risk of obtaining disability pension.
  
  
  RESULTS
  Disability pension rates were higher among cleaners than among other women in unskilled occupations (1.4 per 1,000 person years (CI 95% 1.35-1.46)), but the risk of obtaining disability pension did not increase with increasing exposure to cleaning (HR 0.8 (CI 95% 0.6-1.2)).
  
  
  CONCLUSIONS
  The cleaning occupation has high disability rates compared with other unskilled occupations. A contribution factor to these high rates is a selection of women with poor health into the occupation.
authors.affiliation: University of Oslo, Department of General Practice and Community Medicine, Norway. migle.gamperiene@samfunnsmed.uio.no
authors.forename: Migle
authors.initials: M
authors.lastname: Gamperiene
authors.forename: Jan F
authors.initials: JF
authors.lastname: Nygård
authors.forename: Sören
authors.initials: S
authors.lastname: Brage
authors.forename: Tor
authors.initials: T
authors.lastname: Bjerkedal
authors.forename: Dag
authors.initials: D
authors.lastname: Bruusgaard
mesh_terms: D000328:Adult; D015331:Cohort Studies; D003718:Denmark; D006233:Persons with Disabilities / Q000706:statistics & numerical data*; D004651:Employment / Q000706:statistics & numerical data*; D005260:Female; D006796:Household Work; D006801:Humans; D015994:Incidence; D018868:Insurance, Disability / Q000706:statistics & numerical data*; D008137:Longitudinal Studies; D008875:Middle Aged; D009140:Musculoskeletal Diseases / Q000191:economics / Q000453:epidemiology* / Q000503:physiopathology; D009664:Norway; D009784:Occupational Diseases / Q000191:economics / Q000453:epidemiology* / Q000503:physiopathology; D016272:Occupational Health / Q000706:statistics & numerical data*; D010415:Pensions / Q000706:statistics & numerical data*; D018570:Risk Assessment; D000078329:Workforce