The AMBAR trial assessed the health-related quality of life (HRQoL) impact of plasma exchange with albumin replacement in mild-to-moderate Alzheimer’s disease (AD) patients. Using data from the disease-specific Quality of Life-Alzheimer’s Disease (QoL-AD) questionnaire, EQ-5D-5L utilities were mapped with a model developed by Rombach et al. (2020) to estimate utility values for health economic evaluations.

Key Findings:

• The study included 298 patients and 298 caregivers with complete QoL-AD data.
• At the final visit, the mapped EQ-5D-5L utility mean score was 0.8132 for placebo and 0.8312 for pooled treatment (patient-rated), while proxy-ratings showed 0.7333 for placebo and 0.7235 for treatment.
• The correlation between QoL-AD and EQ-5D-5L utilities was moderate (0.526 for patient ratings and 0.552 for proxies), suggesting only a moderate alignment between these two measures.

Conclusion: The moderate correlation suggests limited conceptual overlap between QoL-AD and EQ-5D-5L, indicating that directly collecting utility measures in AD trials may be more accurate than mapping from disease-specific QoL data. This supports the importance of obtaining direct utility measurements in AD studies for precise health economic evaluations.