title: The validity of EQ-5D US preference weights in liver transplant candidates and recipients.
abstract: Health utility instruments assess patients' valuation of specific health states, which can be converted to quality-adjusted life years for cost-utility analysis. Data from the EQ-5D, a generic health-related quality of life questionnaire from EuroQoL, can be reported as 5 health status scores or as a single health preference weight (HPW). US population-based HPWs were published by Shaw and colleagues in 2005 (Med Care 2005;43:203-220). Our aim was to test the validity of US EQ-5D HPWs and health status scores in liver transplant patients. EQ-5D scores were converted to HPWs with Shaw et al.'s model. Data were stratified by measurement period: pretransplant period, early posttransplant period (< or =12 months), intermediate posttransplant period (13-36 months), and late posttransplant period (>36 months). EQ-5D scores were compared to specific, hypothesized Short Form 36 Health Survey, Center for Epidemiologic Studies Depression Scale, and Beck Anxiety Inventory scores that were identified a priori on the basis of construct similarity. Criterion-related and construct validity were tested with nonparametric methods. Two hundred eighty-five adults participated (113 in the pretransplant period, 60 in the early posttransplant period, 47 in the intermediate posttransplant period, and 65 in the late posttransplant period), and follow-up averaged 36 +/- 36 months. Eighty-one percent of the hypothesized relationships between EQ-5D and gold-standard scales were strong (r > or = |0.5|, P < 0.001), and the remainder were moderate (r > |0.3|, P < 0.001). Differences between pretransplant and posttransplant EQ-5D HPWs were statistically significant. In conclusion, EQ-5D dimensions and the health utility index generated from Shaw's US population preference weights demonstrated criterion-related and construct validity in liver transplant patients. It is a valid instrument for cost-utility analysis in this setting.
authors.affiliation: Department of Surgery and Vanderbilt Transplant Center, Vanderbilt University Medical Center, Nashville, TN 37232-4753., USA. robert.russell@vanderbilt.edu
authors.forename: Robert T
authors.initials: RT
authors.lastname: Russell
authors.forename: Irene D
authors.initials: ID
authors.lastname: Feurer
authors.forename: Panarut
authors.initials: P
authors.lastname: Wisawatapnimit
authors.forename: C Wright
authors.initials: CW
authors.lastname: Pinson
mesh_terms: D000328:Adult; D000368:Aged; D015331:Cohort Studies; D005260:Female; D006801:Humans; D008107:Liver Diseases / Q000628:therapy*; D016031:Liver Transplantation / Q000379:methods*; D008297:Male; D008875:Middle Aged; D011594:Psychometrics / Q000295:instrumentation / Q000379:methods*; D011788:Quality of Life; D015203:Reproducibility of Results; D011795:Surveys and Questionnaires; D016896:Treatment Outcome; D014481:United States