title: The joint contribution of cardiovascular disease and socioeconomic status to disability retirement: A register linkage study.
abstract: BACKGROUND
  Whether low occupational class amplifies the risk of disability retirement among employees with cardiovascular disease (CVD) is unknown. We examined this issue in two prospective cohort studies.
  
  
  METHODS
  In the Finnish Public Sector Study and the Helsinki Health Study (n=50.799 employees), prevalent CVD (coronary heart disease or stroke, n=1269) was ascertained using records from national health registers, self-reported doctor-diagnosed diseases, and Rose Angina Questionnaire. Data linkage to national pension registers allowed the follow up of disability retirement among the participants for a mean of six years. We analysed the associations of occupational class and CVD with disability retirement using Cox regression, tested interactions between occupational class and prevalent CVD in predicting disability retirement by calculating the Synergy Index, and pooled the results from the two studies using fixed-effect meta-analysis.
  
  
  RESULTS
  Compared with the participants from high occupational class and no CVD, the participants from the low occupational class without CVD had a 2.13-fold (95% CI 1.97-2.30), those with high occupational class and CVD a 2.18-fold (1.73-2.74); and those with both low occupational class and CVD a 4.49-fold (3.83-5.26) risk of disability retirement. A Synergy Index of 1.55 (1.16-2.06) suggested a greater than additive effect for low occupational class and CVD in combination.
  
  
  CONCLUSIONS
  Individuals with both low occupational class and CVD are at a particularly high risk of premature exit from the labour market due to work disability. These findings suggest that better preventive strategies are needed to improve prognosis in this risk group.
authors.affiliation: Finnish Institute of Occupational Health, Helsinki, Finland. Electronic address: marianna.virtanen@ttl.fi.
authors.forename: Marianna
authors.initials: M
authors.lastname: Virtanen
authors.affiliation: Finnish Institute of Occupational Health, Helsinki, Finland; Department of Public Health, University of Helsinki, Finland.
authors.forename: Tea
authors.initials: T
authors.lastname: Lallukka
authors.affiliation: Finnish Institute of Occupational Health, Helsinki, Finland.
authors.forename: Jenni
authors.initials: J
authors.lastname: Ervasti
authors.affiliation: Department of Public Health, University of Helsinki, Finland.
authors.forename: Ossi
authors.initials: O
authors.lastname: Rahkonen
authors.affiliation: Department of Public Health, University of Helsinki, Finland.
authors.forename: Eero
authors.initials: E
authors.lastname: Lahelma
authors.affiliation: Finnish Institute of Occupational Health, Turku, Finland.
authors.forename: Jaana
authors.initials: J
authors.lastname: Pentti
authors.affiliation: Department of Public Health, University of Helsinki, Finland.
authors.forename: Olli
authors.initials: O
authors.lastname: Pietiläinen
authors.affiliation: Department of Public Health, University of Turku, Turku, Finland; Turku University Hospital, Turku, Finland.
authors.forename: Jussi
authors.initials: J
authors.lastname: Vahtera
authors.affiliation: Finnish Institute of Occupational Health, Helsinki, Finland; Department of Public Health, University of Helsinki, Finland; Department of Epidemiology and Public Health, University College London, London, UK.
authors.forename: Mika
authors.initials: M
authors.lastname: Kivimäki
mesh_terms: D002318:Cardiovascular Diseases / Q000191:economics / Q000453:epidemiology* / Q000209:etiology; D004185:Disability Evaluation; D006233:Persons with Disabilities / Q000534:rehabilitation*; D005260:Female; D005387:Finland / Q000453:epidemiology; D006801:Humans; D008297:Male; D008875:Middle Aged; D009784:Occupational Diseases / Q000150:complications / Q000453:epidemiology / Q000534:rehabilitation*; D015995:Prevalence; D011379:Prognosis; D011446:Prospective Studies; D012179:Retirement; D012307:Risk Factors; D012959:Socioeconomic Factors
keywords: Cardiovascular disease; Disability; Epidemiology; Prognosis; Socioeconomic factors