title: Long-term physical workload in middle age and disability pension in men and women: a follow-up study of Swedish cohorts.
abstract: OBJECTIVE
  The study investigates the association between level of long-term physical workload in middle age and disability pension (DP) before 61 years of age with adjustments made for early life factors, level of education, and psychosocial working conditions. Associations with DP overall, DP due to musculoskeletal disorders and DP due to psychiatric disorders were examined.
  
  
  METHODS
  The study is based on cohorts of 21,809 Swedish men and women born in 1948 and 1953, with data on physical workload estimated with a job exposure matrix based on occupational titles in 1985 and 1990 and follow-up data on diagnosis-specific DP in the years 1991-2009. Data on paternal education and intelligence were collected in primary school. Data on level of education were taken from administrative records. Data on psychosocial working conditions were estimated with a job exposure matrix based on occupational titles in 1990.
  
  
  RESULTS
  Long-term exposure to high physical workload measured 5 years apart at around age 40 was strongly associated with DP due to musculoskeletal disorders up to the age of 61 among both men (HR 5.44, 95 % CI 3.35-8.84) and women (HR 3.82, CI 95 % 2.88-5.08). For women, the association between high physical load and overall DP was also significantly increased (HR 2.33, CI 95 % 1.92-2.82). The increased risks remained but were clearly attenuated after adjustments for fathers' education, IQ in childhood, achieved education and level of control at work.
  
  
  CONCLUSIONS
  Exposure to high physical workload is associated with long-term risk of DP due to musculoskeletal disorders, even though adjustments for early life factors, level of education and psychosocial working conditions clearly attenuated the risks.
authors.affiliation: Institute of Environmental Medicine, Karolinska Institutet, Solnavägen 4, 10th Floor, 113 65, Stockholm, Sweden. katarina.kjellberg@ki.se.|Centre for Occupational and Environmental Medicine, Stockholm County Council, Stockholm, Sweden. katarina.kjellberg@ki.se.
authors.forename: Katarina
authors.initials: K
authors.lastname: Kjellberg
authors.affiliation: Institute of Environmental Medicine, Karolinska Institutet, Solnavägen 4, 10th Floor, 113 65, Stockholm, Sweden.
authors.forename: Andreas
authors.initials: A
authors.lastname: Lundin
authors.affiliation: Department of Public Health Sciences, Karolinska Institutet, Stockholm, Sweden.
authors.forename: Daniel
authors.initials: D
authors.lastname: Falkstedt
authors.affiliation: Department of Public Health Sciences, Karolinska Institutet, Stockholm, Sweden.
authors.forename: Peter
authors.initials: P
authors.lastname: Allebeck
authors.affiliation: Institute of Environmental Medicine, Karolinska Institutet, Solnavägen 4, 10th Floor, 113 65, Stockholm, Sweden.|Centre for Social Research on Alcohol and Drugs, Stockholm University, Stockholm, Sweden.
authors.forename: Tomas
authors.initials: T
authors.lastname: Hemmingsson
mesh_terms: D000368:Aged; D015331:Cohort Studies; D004522:Educational Status; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D001523:Mental Disorders / Q000453:epidemiology / Q000209:etiology; D008875:Middle Aged; D009140:Musculoskeletal Diseases / Q000453:epidemiology* / Q000209:etiology; D009784:Occupational Diseases / Q000453:epidemiology* / Q000209:etiology; D016273:Occupational Exposure / Q000009:adverse effects*; D009790:Occupations / Q000706:statistics & numerical data; D010415:Pensions / Q000706:statistics & numerical data*; D012307:Risk Factors; D018582:Sick Leave; D013548:Sweden / Q000453:epidemiology; D013997:Time Factors; D016526:Workload / Q000706:statistics & numerical data*
keywords: Cohort study; Education; IQ; Job control; Job exposure matrix; Musculoskeletal disorder