Generic and disease-specific measures of quality of life in patients with mild Alzheimer's disease.

Background/aim: The aim of the study was to investigate the pattern of association of generic and disease-specific quality of life (QoL) scales with standard clinical outcome variables in Alzheimer's disease (AD).

Methods: The participants were 321 home-living patients with mild AD and their primary caregivers from the Danish Alzheimer Intervention Study. QoL was assessed using the generic EuroQol-5D with visual analogue scale (VAS) and the disease-specific Quality of Life in Alzheimer's Disease (QOL-AD) scales (both caregiver and patient rated). Depression, activities of daily living, cognitive performance and neuropsychiatric symptom severity were also assessed.

Results: All 3 caregiver-rated QoL scales correlated significantly with each other (p < 0.001) and with clinical measures. Patient-rated QoL versions correlated inversely with depression (p < 0.001) but not significantly with any other clinical variables.

Conclusion: The caregiver-rated QoL scales showed stronger interscale correlation as well as a similar correlation pattern with standard clinical outcome variables compared to the patient-rated versions. There is some indication that the EQ-5D + VAS could be a suitable alternative to the QOL-AD scale in specific research designs.