title: Reference values for the EORTC QLQ-C30 quality of life questionnaire in a random sample of the Swedish population.
abstract: OBJECTIVE
  To obtain reference values for health-related quality of life (HRQL) measured with the European Organization for Research and Treatment of Cancer (EORTC) Core Quality of Life Questionnaire (QLQ-C30) in a random sample of the adult Swedish population.
  
  
  METHODS
  A population-based survey of a random sample of 7002 Swedish adults aged 40-79 years, frequency-matched to reflect the age and sex distribution of upper gastrointestinal cancer patients. Scales were scored on a 0-100 metric according to standard procedures. Functions and symptoms were dichotomized into "poor" versus "good" function, and "symptomatic" and "no or minor symptoms", respectively. The results were stratified for age and gender.
  
  
  RESULTS
  The questionnaire was completed by 4910 (70.5%) of 6969 eligible participants. Missing values were limited. HRQL was found to vary according to age and sex. Generally, men reported better functioning and fewer symptoms than women. The most common symptoms were fatigue, pain, and insomnia.
  
  
  CONCLUSIONS
  The reference values provided can be used as a surrogate baseline measure in HRQL research, and when evaluating the effect of interventions on HRQL in cancer patients.
authors.affiliation: Upper Gastrointestinal Research, Department of Molecular Medicine and Surgery, Karolinska Institutet, Stockholm, Sweden. maryam.derogar@ki.se
authors.forename: Maryam
authors.initials: M
authors.lastname: Derogar
authors.forename: Maartje
authors.initials: M
authors.lastname: van der Schaaf
authors.forename: Pernilla
authors.initials: P
authors.lastname: Lagergren
mesh_terms: D000328:Adult; D000368:Aged; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009369:Neoplasms; D011788:Quality of Life; D012016:Reference Values; D011795:Surveys and Questionnaires; D013548:Sweden