How Well Does the EQ-5D-Y-5L Describe Children With Intellectual Disability?: “There’s a Lot More to My Child Than That She Can’t Wash or Dress Herself.”

The EQ-5D-5L is a generic health utility instrument for measuring health-related quality of life (HRQoL), with self-report and proxy report versions for children (EQ-5D-Y-5L). Children with intellectual disability (ID) are a heterogeneous population whose impairments and comorbidities place them at risk of poor HRQoL. This study aimed to describe the content validity and suitability for children with ID of a proxy report version of the EQ-5D-Y-5L as seen by their caregivers. A proxy report EQ-5D-Y-5L was administered to caregivers of children with ID. Using cognitive think-aloud interviewing, participants were encouraged to provide the reasoning for their choices, assess the questions’ relevance, comprehensibility, and comprehensiveness, and comment on the tool’s strengths and weaknesses. Qualitative content analysis used both directed (deductive) and conventional (inductive) methods. There were 28 interviews with 30 caregivers of children with ID (aged 8-22 years, 17 boys, with autism spectrum disorder, cerebral palsy, Down syndrome, and rare genetic disorders). The EQ-5D-Y-5L was considered clear, concise, and largely relevant, but insufficiently comprehensive for this population. Interviewees sought clarification of the definition of HRQoL, whether it included unchanging impairments (vs fluctuating health states), and what basis of comparison to use (child or peer). Many interviewees suggested inclusion of questions for other domains, including communication and social engagement, equipment and human supports required, and a wider range of mental health questions. The study suggests that further work is required to ensure accurate responses to the EQ-5D-Y-5L from caregivers of children with ID and to describe these children adequately. •The EQ-5D is a widely used scale for measuring health-related quality of life, with established reliability and validity in a diversity of adult and pediatric populations. It is used to assign economic value to changes in health status.•Use of the EQ-5D-Y-5L presents challenges for carers of children with intellectual disability (ID), particularly in regard to the influence of unchanging impairments, variable expectations for children with ID compared with typically developing children, the omission of questions about supports required by children, and difficulties for parents reporting on behalf of their children, particularly about pain.•Healthcare decision making, if based on a current version of the EQ-5D-Y-5L, is li