title: Validity and reliability of the EQ-5D for cancer patients in Korea.
abstract: OBJECTIVE
  The purpose of this study was to assess the validity and reliability of the Korean version of the EQ-5D health questionnaire for use in patients with cancer in Korea.
  
  
  METHODS
  Patients with colorectal cancer were recruited from one ambulatory cancer center. Each participant consecutively self-administered the EQ-5D, the EORTC QLQ-C30, and the Short Form-36 (SF-36). Discriminatory ability was evaluated by comparing the SF-36 subscales with their corresponding EQ-5D dimensions. Convergent validity was assessed by examining the correlations between the EQ-5D index, EORTC QLQ-C30 subscales, and SF-36 scale and summary scores. Test-retest reliability was also evaluated.
  
  
  RESULTS
  Subjects reporting problems in each EQ-5D dimension showed lower scores on all SF-36 subscales. As expected, the relationships were stronger between the EQ-5D functional dimensions and physical function on the EORTC QLQ-C30 and between the EQ-5D anxiety/depression dimension and emotional function on the EORTC QLQ-C30. The EQ-5D index and SF-36 scales were moderately or highly correlated. intraclass correlation coefficient of the EQ-5D index was 0.45.
  
  
  CONCLUSIONS
  The Korean version of the EQ-5D may be a valid tool for assessing the health-related quality of life of patients with cancer. However, further research is needed to determine the reliability of the Korean EQ-5D over different time intervals and disease conditions.
authors.affiliation: Department of Preventive Medicine, University of Ulsan College of Medicine, 86, Asanbyeongwon-gil, Songpa-gu, Seoul 138-736, Korea.
authors.forename: Seon Ha
authors.initials: SH
authors.lastname: Kim
authors.forename: Jung Sung
authors.initials: JS
authors.lastname: Hwang
authors.forename: Tae Won
authors.initials: TW
authors.lastname: Kim
authors.forename: Yong Sang
authors.initials: YS
authors.lastname: Hong
authors.forename: Min-Woo
authors.initials: MW
authors.lastname: Jo
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015179:Colorectal Neoplasms / Q000523:psychology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011594:Psychometrics / Q000295:instrumentation; D011788:Quality of Life; D015203:Reproducibility of Results; D056910:Republic of Korea; D011795:Surveys and Questionnaires