Comparing the psychometric properties of EQ-5D-3L and EQ-5D-5L proxy ratings by informal caregivers and a health professional for people with dementia.

Compared to the EQ-5D-3L, the EQ-5D-5L had higher feasibility and acceptability and was slightly superior by a reduction of ceiling effects and an improvement in informativity, discriminative ability and convergent validity. Proxy ratings by informal caregivers overall demonstrated better psychometric properties than professional care-manager ratings.