title: Contribution of chronic diseases to the mild and severe disability burden in Belgium.
abstract: BACKGROUND
  Population aging accompanied by an increased longevity with disability has raised international concern, especially due to its costs to the health care systems. Chronic diseases are the main causes of physical disability and their simultaneous occurrence in the population can impact the disablement process, resulting in different severity levels. In this study, the contribution of chronic diseases to both mild and severe disability burden in Belgium was investigated.
  
  
  METHODS
  Data on 21 chronic diseases and disability from 35,799 individuals aged 15 years or older who participated in the 1997, 2001, 2004, or 2008 Belgian Health Interview Surveys were analysed. Mild and severe disability were defined based on questions related to six activities of daily living and/or mobility limitations. To attribute disability by severity level to selected chronic diseases, multiple additive hazard models were fitted to each disability outcome, separately for men and women.
  
  
  RESULTS
  A stable prevalence of mild (5 %) and severe (2-3 %) disability was observed for the Belgian population aged 15 years or older between 1997 and 2008. Arthritis was the most important contributor in women with mild and severe disability. In men, low back pain and chronic respiratory diseases contributed most to the mild and severe disability burden, respectively. The contribution also differed by age: for mild disability, depression and chronic respiratory diseases were important contributors among young individuals, while heart attack had a large contribution for older individuals. For severe disability, neurological diseases and stroke presented a large contribution in young and elderly individuals, respectively.
  
  
  CONCLUSIONS
  Our results indicate that the assessment of the contribution of chronic diseases on disability is more informative if different levels of disability are taken into consideration. The identification of diseases which are related to different levels of disability - mild and severe - can assist policymakers in the definition and prioritisation of strategies to tackle disability, involving prevention, rehabilitation programs, support services, and training for disabled individuals.
authors.affiliation: Department of Public Health and Surveillance, Scientific Institute of Public Health, Rue Juliette Wytsmanstraat 14, Brussels, 1050 Belgium ; Department of Social Research, Interface Demography, Vrije Universiteit Brussel, Brussels, 1050 Belgium.
authors.forename: Renata T C
authors.initials: RT
authors.lastname: Yokota
authors.affiliation: Department of Public Health and Surveillance, Scientific Institute of Public Health, Rue Juliette Wytsmanstraat 14, Brussels, 1050 Belgium ; Department of Public Health, Ghent University, Ghent, Belgium.
authors.forename: Johan
authors.initials: J
authors.lastname: Van der Heyden
authors.affiliation: Department of Public Health and Surveillance, Scientific Institute of Public Health, Rue Juliette Wytsmanstraat 14, Brussels, 1050 Belgium.
authors.forename: Stefaan
authors.initials: S
authors.lastname: Demarest
authors.affiliation: Department of Public Health and Surveillance, Scientific Institute of Public Health, Rue Juliette Wytsmanstraat 14, Brussels, 1050 Belgium.
authors.forename: Jean
authors.initials: J
authors.lastname: Tafforeau
authors.affiliation: Department of Public Health, Erasmus MC, Rotterdam, The Netherlands.
authors.forename: Willma J
authors.initials: WJ
authors.lastname: Nusselder
authors.affiliation: Department of Social Research, Interface Demography, Vrije Universiteit Brussel, Brussels, 1050 Belgium.
authors.forename: Patrick
authors.initials: P
authors.lastname: Deboosere
authors.affiliation: Department of Public Health and Surveillance, Scientific Institute of Public Health, Rue Juliette Wytsmanstraat 14, Brussels, 1050 Belgium ; Department of Public Health, Ghent University, Ghent, Belgium.
authors.forename: Herman
authors.initials: H
authors.lastname: Van Oyen
keywords: Activity of daily living; Belgium; Chronic diseases; Mild disability; Mobility limitations; Severe disability