Is EQ-5D-5L Better Than EQ-5D-3L Over Time? A Head-to-Head Comparison of Responsiveness of Descriptive Systems and Value Sets from Nine Countries.

Descriptive results were the main driver of 3L-5L responsiveness differences. Responsiveness of 3L was influenced by the 'confined to bed' label and the overestimation bias of 3L, which affected all responsiveness results. This may impact quality-adjusted life-year (QALY) estimations, leading to over- or underestimations of QALYs gained, depending on the condition and condition severity. QALY calculations based on 5L data will result in more accurate estimates.