Why Do Adults Value EQ-5D-Y-3L Health States Differently for Themselves Than for Children and Adolescents: A Think-Aloud Study

Objectives: Following protocol, adults value EQ-5D-Y-3L health states from the perspective of a 10-year-old child. It remains unclear why adults value health states differently for themselves than for a 10-year-old child and whether the latter perspective is representative of adults' preferences for the 8 to 15 years age range of the EQ-5D-Y-3L. This study examines the reasons underlying (potential) differences in adults' health-state preferences for themselves, a 10-year-old child, and 15-year-old adolescent. Methods: We conducted semistructured interviews using a think-aloud protocol with 25 participants who performed valuation tasks in July 2020 to August 2020. Using the Framework Method, we developed 28 categories grouped under 5 themes that illustrated the differences emerging from the interviews. Results: Participants (A) deemed it more straining to perform valuation tasks for a 10-year-old child and 15-year-old adolescent than for themselves, (B) had a stable self-image, but varied in whom they imagined as 10-year-old child and 15-year-old adolescent, (C) focused on different dimensions and levels for a 15-year-old adolescent than for a 10-year-old child and themselves, (D) had various thoughts about nonhealth-related factors that influenced their preferences, and (E) gave up relatively few life-years for a 10-year-old child and 15-year-old adolescent, also to avoid others bearing a grudge against them. Conclusions: Our results indicate that differences in adults' health-state preferences for themselves and a 10-year-old child largely result from differences in thoughts about nonhealth-related factors. They further indicate that health-state preferences for a 10-year-old child may not be representative of such preferences for the full EQ-5D-Y-3L age range.