Justifying and Classifying Adults' Roles in Child Health State Valuation: A Novel Taxonomy.

For cost-utility analyses for children, health-related quality of life (HRQOL) is commonly measured using paediatric instruments such as EQ-5D-Y, yet associated value sets are typically derived from adult preferences. This practice raises a fundamental normative question: whose preferences, and thus whose values, should count when valuing child HRQOL? Recent academic critique has focused on whether children have the fundamental right and ability to provide preferences and hence should be involved in valuing child HRQOL, yet the default position, that preferences of adult members of the general public should (at least partially) determine the importance of changes in child HRQOL, remains unchallenged. This perspective critically examines the role adults have in the valuation of child HRQOL. We first revisit the dominant justification for adult involvement in valuation, i.e. the taxpayer argument, and show that recent empirical evidence from public, stakeholder and expert studies offers little support for this rationale. We then explore alternative normative arguments for involving adults, and propose a typology of ten distinct roles adults could take in valuation of child HRQOL, from being the sole source of preference information to acting as partners, caretakers or only gatekeepers that enable children themselves to value child HRQOL. We argue that greater conceptual clarity about why and how adults are involved is essential for the future development of paediatric value sets for use in economic evaluations, thereby strengthening the legitimacy, transparency and practical use of paediatric HRQOL instruments in policy and decision making, and identify several high priority research gaps.