In the valuation of EQ-5D-Y-3L, adults are asked to value health states for a 10-year-old child, but this change compared with the valuation of adult health states has been a source of ongoing discussion.

In this study, we investigated an alternative perspective: i.e. adults considered what they think a 10-year-old child would decide for itself.

We find systematic differences between composite time trade-off responses given by adults deciding for children and adults considering what children would want for themselves.