Introduction
Alzheimer's and Lewy body dementias, cognitive symptoms
The EQ-5D-5L is a widely used preference-based generic instrument that measures today's self-rated health-related quality of life (HRQoL) (So far, challenges in measuring HRQoL and the impact of health state fluctuations have not been well-understood. Fluctuations of predominantly cognitive symptoms have been assessed clinically for Alzheimer's and Lewy body dementias (Thus, the lack of understanding of the questionnaire and its recall period might influence the assessment of the patient's actual HRQoL status, especially in those experiencing recurrent health fluctuations (