title: QLU-C10D: a health state classification system for a multi-attribute utility measure based on the EORTC QLQ-C30.
abstract: OBJECTIVE
  To derive a health state classification system (HSCS) from the cancer-specific quality of life questionnaire, the EORTC QLQ-C30, as the basis for a multi-attribute utility instrument.
  
  
  METHODS
  The conceptual model for the HSCS was based on the established domain structure of the QLQ-C30. Several criteria were considered to select a subset of dimensions and items for the HSCS. Expert opinion and patient input informed a priori selection of key dimensions. Psychometric criteria were assessed via secondary analysis of a pooled dataset comprising HRQOL and clinical data from 2616 patients from eight countries and a range of primary cancer sites, disease stages, and treatments. We used confirmatory factor analysis (CFA) to assess the conceptual model's robustness and generalisability. We assessed item floor effects (>75 % observations at lowest score), disordered item response thresholds, coverage of the latent variable and differential item function using Rasch analysis. We calculated effect sizes for known group comparisons based on disease stage and responsiveness to change. Seventy-nine cancer patients assessed the relative importance of items within dimensions.
  
  
  RESULTS
  CFA supported the conceptual model and its generalisability across primary cancer sites. After considering all criteria, 12 items were selected representing 10 dimensions: physical functioning (mobility), role functioning, social functioning, emotional functioning, pain, fatigue, sleep, appetite, nausea, bowel problems.
  
  
  CONCLUSIONS
  The HSCS created from QLQ-C30 items is known as the EORTC Quality of Life Utility Measure-Core 10 dimensions (QLU-C10D). The next phase of the QLU-C10D's development involves valuation studies, currently planned or being conducted across the globe.
authors.affiliation: Psycho-Oncology Cooperative Research Group (PoCoG), School of Psychology, Faculty of Science, University of Sydney, Sydney, NSW, Australia. madeleine.king@sydney.edu.au.|Central Clinical School, Sydney Medical School, Faculty of Medicine, University of Sydney, Sydney, NSW, Australia. madeleine.king@sydney.edu.au.
authors.forename: M T
authors.initials: MT
authors.lastname: King
authors.affiliation: Psycho-Oncology Cooperative Research Group (PoCoG), School of Psychology, Faculty of Science, University of Sydney, Sydney, NSW, Australia.
authors.forename: D S J
authors.initials: DS
authors.lastname: Costa
authors.affiliation: Division of Psychosocial Research & Epidemiology, The Netherlands Cancer Institute, Amsterdam, The Netherlands.
authors.forename: N K
authors.initials: NK
authors.lastname: Aaronson
authors.affiliation: Health Economics and Decision Science, School of Health and Related Research, University of Sheffield, Sheffield, South Yorkshire, UK.
authors.forename: J E
authors.initials: JE
authors.lastname: Brazier
authors.affiliation: Department of Medical Social Sciences, Feinberg School of Medicine, Northwestern University, Chicago, IL, USA.
authors.forename: D F
authors.initials: DF
authors.lastname: Cella
authors.affiliation: Institute of Applied Health Sciences, University of Aberdeen, Aberdeen, UK.|Department of Cancer Research and Molecular Medicine, Norwegian University of Science and Technology (NTNU), Trondheim, Norway.
authors.forename: P M
authors.initials: PM
authors.lastname: Fayers
authors.affiliation: Chris O'Brien Lifehouse, Sydney Medical School, University of Sydney, Sydney, NSW, Australia.
authors.forename: P
authors.initials: P
authors.lastname: Grimison
authors.affiliation: School of Public Health, Institute of Health and Biomedical Innovation, Queensland University of Technology, Brisbane, QLD, Australia.
authors.forename: M
authors.initials: M
authors.lastname: Janda
authors.affiliation: Department of Psychiatry and Psychotherapy, Innsbruck Medical University, Innsbruck, Austria.
authors.forename: G
authors.initials: G
authors.lastname: Kemmler
authors.affiliation: School of Public Health, Curtin University, Perth, WA, Australia.|Centre for Health Economics Research and Evaluation (CHERE), University of Technology Sydney (UTS), Sydney, NSW, Australia.
authors.forename: R
authors.initials: R
authors.lastname: Norman
authors.affiliation: Department of Pharmacy Systems, Outcomes and Policy, College of Pharmacy, University of Illinois at Chicago, Chicago, IL, USA.
authors.forename: A S
authors.initials: AS
authors.lastname: Pickard
authors.affiliation: Health Economics and Decision Science, School of Health and Related Research, University of Sheffield, Sheffield, South Yorkshire, UK.
authors.forename: D
authors.initials: D
authors.lastname: Rowen
authors.affiliation: Leeds Institute of Cancer and Pathology, University of Leeds, St James's University Hospital, Leeds, UK.
authors.forename: G
authors.initials: G
authors.lastname: Velikova
authors.affiliation: Health Economics and Decision Science, School of Health and Related Research, University of Sheffield, Sheffield, South Yorkshire, UK.
authors.forename: T A
authors.initials: TA
authors.lastname: Young
authors.affiliation: Centre for Health Economics Research and Evaluation (CHERE), University of Technology Sydney (UTS), Sydney, NSW, Australia.
authors.forename: R
authors.initials: R
authors.lastname: Viney
mesh_terms: D000328:Adult; D000368:Aged; D005163:Factor Analysis, Statistical; D005221:Fatigue / Q000150:complications; D005260:Female; D006304:Health Status; D006801:Humans; D008297:Male; D008875:Middle Aged; D009369:Neoplasms / Q000150:complications; D010146:Pain / Q000150:complications; D010809:Physical Fitness; D011594:Psychometrics / Q000379:methods; D011788:Quality of Life / Q000523:psychology*; D015203:Reproducibility of Results; D011795:Surveys and Questionnaires
keywords: Cancer; Multi-attribute utility instrument; QLQ-C30; Quality of life; Utility