Measuring health-related quality-of-life for Alzheimer's disease using the general public

Purpose Little research exists to indicate whether the general public can provide proxy health-related quality-of-life (HRQoL) estimates for persons with Alzheimer's disease (AD). We investigated (1) whether the general public can differentiate between mild, moderate, and severe AD and (2) whether the general public's proxy HRQoL estimates are correlated with current health status. Methods We conducted computer-assisted personal interviews. The computer randomly assigned each participant to read a vignette describing mild, moderate, or severe AD. Participants answered the EQ-5D-5L and Quality-of-life-Alzheimer's Disease (QoL-AD), while imagining living in the health state described in their assigned vignette. Participants also answered the EQ-5D-5L based on their health state at the time of the interview. Results We interviewed 100 participants. EQ-5D-5L utilities were 0.7413 (mild), 0.6159 (moderate), and 0.4456 (severe) (P < 0.001). Mean QoL-AD scores were 32.5 (mild), 24.0 (moderate), and 21.8 (severe) (P < 0.0001 for severe vs. mild, moderate vs. mild; P > 0.05 for severe vs. moderate). Participants' EQ-5D-5L utility scores were weakly correlated (r <= 0.28) across both administrations of the instrument. Conclusions The general public can differentiate between the three stages of AD, and their HRQoL estimates for AD are weakly correlated with their current health status.