title: Multiple chronic health problems are negatively associated with health related quality of life (HRQoL) irrespective of age.
abstract: OBJECTIVE
  To examine HRQoL measured by EORTC QLQ-C30 with respect to an increasing number of self-reported chronic health problems in the general Swedish population and to study the association between HRQoL, chronic health problems and age, gender, income, marital status and employment status.
  
  
  METHODS
  A postal survey among a large random sample of 4000 adults aged 18-79 years. The study material contained EORTC QLQ-C30 core questionnaire supplemented by a sociodemographic questionnaire including questions about 13 chronic health problems of which four categories, 'No', 'Few', 'Some' or 'A lot of chronic health problems were constructed.
  
  
  RESULTS
  Multiple chronic health problems were significantly associated with reduced HRQoL. The increased number of chronic health problems was also associated with age. When the number of chronic health problems was accounted for, the influence of age diminished. Low income and unemployment were associated with greater decline in HRQoL with respect to increasing number of problems among the respondents in working age.
  
  
  CONCLUSIONS
  The impact of increased number of chronic health problems had varying consequences in different age groups. Moreover, sociodemographic and economic factors showed to interact differently with chronic health problems and HRQoL in various age groups. It appears from our results that an assessment and a careful consideration of these factors will be valuable in order to facilitate the interpretation of the effects of cancer and treatment on long-term HRQoL of cancer patients.
authors.affiliation: Department of Oncology, Radiumhemmet, Stockholm, Sweden. Helena.Michelson@onkpat.ki.se
authors.forename: H
authors.initials: H
authors.lastname: Michelson
authors.forename: C
authors.initials: C
authors.lastname: Bolund
authors.forename: Y
authors.initials: Y
authors.lastname: Brandberg
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000368:Aged; D002908:Chronic Disease / Q000145:classification / Q000453:epidemiology* / Q000523:psychology; D004651:Employment / Q000706:statistics & numerical data; D005260:Female; D006801:Humans; D007182:Income / Q000706:statistics & numerical data; D008297:Male; D017533:Marital Status / Q000706:statistics & numerical data; D008875:Middle Aged; D011788:Quality of Life; D011897:Random Allocation; D012042:Registries; D012494:Sampling Studies; D012959:Socioeconomic Factors; D011795:Surveys and Questionnaires; D017741:Survivors / Q000523:psychology; D013548:Sweden / Q000453:epidemiology