title: Summary scores captured changes in subjects' QoL as measured by the multiple scales of the EORTC QLQ-C30.
abstract: OBJECTIVE
  To examine the performance of the European Organization for Research and Treatment of Cancer Quality of Life Questionnaire Core 30 (EORTC QLQ-C30) global health status/quality of life (QoL) scale and two summary scores to detect changes in the QoL profile over time, according to changes in the individual scales.
  
  
  METHODS
  Data came from 167 clinical trial patients with unresectable (advanced) hepatocellular carcinoma. The global health status/QoL scale of the questionnaire contained two items: overall health and overall QoL. Nordin and Hinz proposed summary scores for the questionnaire. A mixed-effect model was fitted to estimate trends in scores over time.
  
  
  RESULTS
  Predominantly the individual scale scores declined over time; however, the global health status/QoL score was stable [rate of change = -0.3 per month; 95% confidence interval (CI): -1.2, 0.6]. Nordin's summary score, which gave equal weight to the 15 questionnaire scales, and Hinz's summary score, which gave equal weight to the 30 questionnaire items, showed a statistically significant decline over time, 3.4 (95% CI: -4.5, -2.4) and 4.2 (95% CI: -5.3, -3.0) points per month, respectively.
  
  
  CONCLUSIONS
  In contrast to the global health status/QoL scale, the summary scores proposed by Nordin and Hinz detected changes in subjects' QoL profile described by the EORTC QLQ-C30 individual scales.
authors.affiliation: Biostatistics Department, Singapore Clinical Research Institute, 31 Biopolis Way, Nanos #0201, Singapore 138669; Centre for Quantitative Medicine, Office of Clinical Sciences, Academia, 20 College Road, Singapore Duke-NUS Graduate Medical School, Singapore. Electronic address: rachel.phillips@scri.edu.sg.
authors.forename: Rachel
authors.initials: R
authors.lastname: Phillips
authors.affiliation: Biostatistics Department, Singapore Clinical Research Institute, 31 Biopolis Way, Nanos #0201, Singapore 138669; Centre for Quantitative Medicine, Office of Clinical Sciences, Academia, 20 College Road, Singapore Duke-NUS Graduate Medical School, Singapore; Department of International Health, School of Medicine, Lääkärinkatu 1, 33014 University of Tampere, Tampere, Finland.
authors.forename: Mihir
authors.initials: M
authors.lastname: Gandhi
authors.affiliation: Biostatistics Department, Singapore Clinical Research Institute, 31 Biopolis Way, Nanos #0201, Singapore 138669.
authors.forename: Yin Bun
authors.initials: YB
authors.lastname: Cheung
authors.affiliation: Discipline of Oncology, Faculty of Medical and Health Sciences, The University of Auckland, Private Bag 92019, Auckland Mail Centre, Auckland 1142, New Zealand.
authors.forename: Michael P
authors.initials: MP
authors.lastname: Findlay
authors.affiliation: Department of Hepatology, Yangon GI and Liver Centre, 91-193, 30th Street (Upper Block), Pabedan Township, Yangon 11141, Myanmar.
authors.forename: Khin Maung
authors.initials: KM
authors.lastname: Win
authors.affiliation: Training and Research Department, Cho Ray Hospital, 201B Nguyen Chi Thanh Street, District 5, Ho Chi Minh City, Vietnam.
authors.forename: Hoang Hoa
authors.initials: HH
authors.lastname: Hai
authors.affiliation: Department of Internal Medicine, Catholic University Medical College, 93-6 Chi-dong, Paldal-ku, Suwon 442-720, Korea.
authors.forename: Jin Mo
authors.initials: JM
authors.lastname: Yang
authors.affiliation: Department of Liver and Pancreatic-Biliary Surgery, Davao Doctors Hospital, Quirino Street, Davao City, The Philippines.
authors.forename: Rolley Rey
authors.initials: RR
authors.lastname: Lobo
authors.affiliation: Centre for Quantitative Medicine, Office of Clinical Sciences, Academia, 20 College Road, Singapore Duke-NUS Graduate Medical School, Singapore; Department of Surgical Oncology, National Cancer Center Singapore, 11 Hospital Drive, Singapore 169610.
authors.forename: Khee Chee
authors.initials: KC
authors.lastname: Soo
authors.affiliation: Centre for Quantitative Medicine, Office of Clinical Sciences, Academia, 20 College Road, Singapore Duke-NUS Graduate Medical School, Singapore; Department of Surgical Oncology, National Cancer Center Singapore, 11 Hospital Drive, Singapore 169610; Deparment Hepatopancreatobiliary and Transplant Surgery, Singapore General Hospital, Outram Road, Singapore 169608.
authors.forename: Pierce K H
authors.initials: PK
authors.lastname: Chow
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000465:Algorithms; D006528:Carcinoma, Hepatocellular / Q000523:psychology* / Q000628:therapy*; D004812:Epidemiologic Methods; D005260:Female; D006305:Health Status Indicators; D006801:Humans; D008113:Liver Neoplasms / Q000523:psychology* / Q000628:therapy*; D008297:Male; D008875:Middle Aged; D011594:Psychometrics; D011788:Quality of Life; D018434:Sickness Impact Profile; D011795:Surveys and Questionnaires
keywords: Advanced hepatocellular carcinoma; Cancer; EORTC QLQ-C30; Quality of life; Response shift; Scoring procedure