Journal of Clinical Epidemiology 57 (2004) 1161–1166 Health-related quality of life (HRQL) scores reported from parents and their children with chronic illness differed depending on utility elicitation method L. Sung a,b,c,d, * , N.L. Young a,b,d , M.L. Greenberg a,c , M. McLimont d , T. Samanta d , J. Wong d , J. Rubenstein d , S. Ingber d , J.J. Doyle a,c , B.M. Feldman a,b,d,e,f a Department of Pediatrics, University of Toronto, Toronto, Ontario, Canada b Department of Health Policy Management and Evaluation, University of Toronto, Toronto, Ontario, Canada c Division of Hematology/Oncology, Hospital for Sick Children, Toronto, Ontario M5G 1X8, Canada d Division of Population Health Sciences, Hospital for Sick Children, Toronto, Ontario, Canada e Department of Public Health Sciences, University of Toronto, Toronto, Ontario, Canada f Division of Rheumatology, Hospital for Sick Children, Toronto, Ontario, Canada Accepted 17 May 2004 Abstract Objective: To describe the relationship between health-related quality of life (HRQL) as measured by utility when elicited from parents and their children with chronic illness. Study Design and Setting: We enrolled families of children admitted for cancer chemotherapy and those attending outpatient rheumatology, hemophilia and bone marrow transplantation clinics. Children in grade 6 or higher were included. The child’s HRQL was rated by parent and child using the Standard Gamble (SG), Visual Analogue Scale (VAS), Time Trade-Off (TTO), and Health Utilities Index Mark 2/3 (HUI2 and HUI3). Results: 22 families were included. The mean parent SG was 0.92  0.09, which was similar to the mean SG elicited from their children of 0.92  0.10. The parent and child SG were moderately concordant (ICC = 0.64, 95% CI = 0.30, 0.83; P = .0005). In contrast, TTO scores were not concordant (ICC = 0.14, 95% CI =-0.29, 0.53; P = .3), with parents (mean TTO = 0.77  0.31) rating HRQL worse than children (mean TTO = 0.92  0.11; P = .04). Similarly, the mean parent HUI2 of 0.82  0.22 was lower than the child HUI2 of 0.95  0.07; P = .02 and HUI2 were not concordant (ICC = 0.11, 95% CI =-0.35, 0.53; P = .3) between parents and children. Conclusion: Parents and children rate HRQL similarly according to SG, but parents rate HRQL significantly worse using TTO and HUI2.  2004 Elsevier Inc. All rights reserved. Keywords: Health-related quality of life; Standard Gamble; Visual Analogue Scale; Time Trade-Off; Health Utilities Index; Utility; Children 1. Background Parents are frequently asked to act as a proxy in the elicitation of health-related quality of life (HRQL) for chil- dren who are too young or too ill to provide a meaningful re- sponse. Eiser and Morse [1] recently reviewed 14 studies in which parent and child assessments of HRQL were com- pared. In general, they found that parents and children agreed upon more observable phenomenon such as level of physical activity, functioning and symptoms; conversely, poor agreement was seen in more subjective areas, such as social or emotional domains. Eiser and Morse [1] concluded that differences in HRQL as reported by parents and children * Corresponding author. Tel.: 416-813-5287; fax: 416-813-5327. E-mail address: Lillian.sung@sickkids.ca (L. Sung). 0895-4356/04/$ – see front matter  2004 Elsevier Inc. All rights reserved. doi: 10.1016/j.jclinepi.2004.05.003 may reflect real differences in the perception of HRQL, rather than poor measurement properties of the instrument. The vast majority of studies comparing proxy and self- assessment of HRQL in pediatrics have examined question- naire-based methods of HRQL measurement. Very little work has examined proxy measurement of utility. Utility can be defined as the strength of an individual’s preference for a health state measured under conditions of uncertainty and reflects the axioms of von Neumann– Morgenstern utility theory [2]. Global health state utilities are an important measure of HRQL, in part because of their use in decision and economic analyses. The most commonly accepted method for measurement of utility is the Standard Gamble (SG) [3]. A SG utility is, by convention, repre- sented by a number that ranges from 0, which represents death or the worst possible health, to 1, which represents perfect or