title: Comparing the psychometric properties of the EQ-5D-3L and EQ-5D-5L in cancer patients in Korea.
abstract: OBJECTIVE
  This study was conducted to assess the redistribution properties of the EQ-5D-3L when using the EQ-5D-5L and to compare the validity, informativity, and reliability of both EQ-5D-3L and EQ-5D-5L in Korean cancer patients.
  
  
  METHODS
  Patients visiting one ambulatory cancer center self-administered the two versions of the EQ-5D and the EORTC QLQ-C30 questionnaire. Redistribution properties in each dimension of EQ-5D were analyzed between EQ-5D-3L and EQ-5D-5L. Informativity was evaluated using the Shannon entropy and ceiling effect. Convergent validity was evaluated by comparing the EQ-VAS, ECOG performance status, and EORTC QLQ-C30 subscales. Reliability was also evaluated in terms of test-retest reliability.
  
  
  RESULTS
  All levels of the EQ-5D-3L substantially partitioned into associated levels of the EQ-5D-5L. The average inconsistency rate of the two versions was 3.5%. Absolute informativity was higher for the EQ-5D-5L than for the EQ-5D-3L, but their informative efficiency tended to be similar. The proportion of 'perfect health' (11111) decreased from 16.8% in the EQ-5D-3L to 9.7% in the EQ-5D-5L. EQ-5D-5L demonstrated similar or higher correlations with the EQ-VAS, ECOG performance status, and EORTC QLQ-C30, than the EQ-5D-3L. The intraclass correlation coefficient of the EQ-5D-5L index was 0.77.
  
  
  CONCLUSIONS
  The EQ-5D-5L had greater informativity and lower rate in the ceiling effect than those values of the EQ-5D-3L. The EQ-5D-5L showed good construct validity and reasonable reliability. Therefore, considering these findings, the EQ-5D-5L may be preferable to the EQ-5D-3L.
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: Hwa Jung
authors.initials: HJ
authors.lastname: Kim
authors.forename: Sang-Il
authors.initials: SI
authors.lastname: Lee
authors.forename: Min-Woo
authors.initials: MW
authors.lastname: Jo
mesh_terms: D000203:Activities of Daily Living; D005260:Female; D006305:Health Status Indicators; D006801:Humans; D008297:Male; D009369:Neoplasms / Q000523:psychology*; D010147:Pain Measurement / Q000379:methods*; D011594:Psychometrics / Q000379:methods*; D011788:Quality of Life; D015203:Reproducibility of Results; D056910:Republic of Korea; D011795:Surveys and Questionnaires