title: Examining the relationships among health-related quality-of-life indicators in cancer patients participating in clinical trials: a pooled study of baseline EORTC QLQ-C30 data.
abstract: OBJECTIVE
  Cancer patients experience multiple and concurrent health-related problems and symptoms due to their illness and therapies. The first objective of this analysis was to identify how health-related quality-of-life (HRQoL) indicators cluster among cancer patients and how possible clusters change across patients with different sociodemographic and clinical characteristics. The second objective of this study was to identify which HRQoL indicators are linked to patients' perception of overall quality of life.
  
  
  METHODS
  Retrospective pooling of 30 closed randomized European Organisation for Research and Treatment of Cancer (EORTC) clinical trials yielded baseline EORTC Quality of Life Core Questionnaire (QLQ-C30) HRQoL data for a total of 7417 patients. A cluster analysis was performed to determine how the 15 HRQoL indicators obtained with the QLQ-C30 cluster overall and by patient characteristics.
  
  
  RESULTS
  Three main clusters emerged from the overall dataset: a physical cluster, a psychological cluster and a gastrointestinal cluster. The same clusters were found in subgroups defined according to sociodemographic and clinical characteristics, while some differences emerged among cancer sites. The Global Health scale was found to be part of the physical cluster in the overall dataset. This result was consistent across different levels of disease severity, while divergent results were seen across some cancer sites.
  
  
  CONCLUSIONS
  Our findings suggest that HRQoL indicators are interrelated. Understanding these relationships may aid clinicians in managing the symptom burden experienced by patients, as well as policy-makers, in defining psychosocial support plans.
authors.affiliation: Quality of Life Department, European Organisation for Research and Treatment of Cancer, Brussels, Belgium. francesca.martinelli@eortc.be
authors.forename: Francesca
authors.initials: F
authors.lastname: Martinelli
authors.forename: Chantal
authors.initials: C
authors.lastname: Quinten
authors.forename: John T
authors.initials: JT
authors.lastname: Maringwa
authors.forename: Corneel
authors.initials: C
authors.lastname: Coens
authors.forename: Jurgen
authors.initials: J
authors.lastname: Vercauteren
authors.forename: Charles S
authors.initials: CS
authors.lastname: Cleeland
authors.forename: Henning
authors.initials: H
authors.lastname: Flechtner
authors.forename: Carolyn
authors.initials: C
authors.lastname: Gotay
authors.forename: Eva
authors.initials: E
authors.lastname: Greimel
authors.forename: Madeleine
authors.initials: M
authors.lastname: King
authors.forename: Tito
authors.initials: T
authors.lastname: Mendoza
authors.forename: David
authors.initials: D
authors.lastname: Osoba
authors.forename: Bryce B
authors.initials: BB
authors.lastname: Reeve
authors.forename: Jolie
authors.initials: J
authors.lastname: Ringash
authors.forename: Joseph Schmucker-Von
authors.initials: JS
authors.lastname: Koch
authors.forename: Qiuling
authors.initials: Q
authors.lastname: Shi
authors.forename: Martin J
authors.initials: MJ
authors.lastname: Taphoorn
authors.forename: Joachim
authors.initials: J
authors.lastname: Weis
authors.forename: Andrew
authors.initials: A
authors.lastname: Bottomley
mesh_terms: D000328:Adult; D000368:Aged; D002986:Clinical Trials as Topic; D005260:Female; D006304:Health Status; D006801:Humans; D008297:Male; D008875:Middle Aged; D009369:Neoplasms / Q000523:psychology*; D011788:Quality of Life; D011795:Surveys and Questionnaires