title: Determinants of levels and changes of physical functioning in chronically ill persons: results from the GLOBE Study.
abstract: OBJECTIVE
  Declines in physical functioning are a common result of chronic illness, but relatively little is known about factors not directly related to severity of disease that influence the occurrence of disability among chronically ill persons. The aim of this study was to assess the effect of a large number of potential determinants (sociodemographic factors, health related behaviour, structural living conditions, and psychosocial factors).
  
  
  METHODS
  Longitudinal study of levels and changes of physical functioning among persons suffering from four chronic diseases (asthma/chronic obstructive pulmonary disease (COPD), heart disease, diabetes, chronic low back pain). In 1991, persons suffering from one or more of these diseases were identified in a general population survey. Self reported disabilities, using a subset of the OECD disability indicator, were measured six times between 1991 and 1997. These data were analysed using generalised estimating equations, relating determinants measured in 1991 to disability between 1991 and 1997, and controlling for a number of potential confounders (age, gender, year of measurement, and type and severity of chronic disease).
  
  
  METHODS
  Region of Eindhoven (south eastern Netherlands).
  
  
  METHODS
  1784 persons with asthma/COPD, heart disease, diabetes mellitus and/or low back pain.
  
  
  RESULTS
  In a "repeated prevalence" model, statistically significant (p<0.05) and strong associations were found between most of the determinants and the prevalence of disabilities. In a "longitudinal change" model, statistically significant (p<0.05) predictors of unfavourable changes in physical functioning were low income and excessive alcohol consumption, while we also found indications for effects of marital status, degree of urbanisation, smoking, and external locus of control.
  
  
  CONCLUSIONS
  Other factors than characteristics of the underlying disease have an important influence on levels and changes of physical functioning among chronically ill persons. Reduction of the prevalence of disabilities in the population not only depends on medical interventions, but may also require social interventions, health education, and psychological interventions among chronically ill persons.
authors.affiliation: Department of Public Health, Erasmus University Rotterdam, PO Box 1738, 3000 DR Rotterdam, The Netherlands. mackenbach@mgz.fgg.eur.nl
authors.forename: J P
authors.initials: JP
authors.lastname: Mackenbach
authors.forename: G J
authors.initials: GJ
authors.lastname: Borsboom
authors.forename: W J
authors.initials: WJ
authors.lastname: Nusselder
authors.forename: C W
authors.initials: CW
authors.lastname: Looman
authors.forename: C T
authors.initials: CT
authors.lastname: Schrijvers
mesh_terms: D000203:Activities of Daily Living; D000293:Adolescent; D000328:Adult; D000368:Aged; D001249:Asthma / Q000453:epidemiology / Q000503:physiopathology; D002908:Chronic Disease; D003920:Diabetes Mellitus / Q000453:epidemiology / Q000503:physiopathology*; D004185:Disability Evaluation; D005260:Female; D006331:Heart Diseases / Q000453:epidemiology / Q000503:physiopathology*; D006801:Humans; D008137:Longitudinal Studies; D017116:Low Back Pain / Q000453:epidemiology / Q000503:physiopathology*; D008173:Lung Diseases, Obstructive / Q000453:epidemiology / Q000503:physiopathology*; D008297:Male; D008875:Middle Aged; D010809:Physical Fitness; D015995:Prevalence; D012307:Risk Factors; D012959:Socioeconomic Factors; D011795:Surveys and Questionnaires