Quality of life in mild dementia: patterns of change in self and caregiver ratings over time

Objectives: To determine changes over time in self and caregiver ratings of quality of life (QoL) in people with dementia (PwD) and to identify factors associated with changes in QoL ratings. Methods: In this longitudinal study, 69 people with mild Alzheimer's disease and their caregivers were assessed at baseline and after 1 year. We examined the association of QoL ratings with the following variables at the two time points: awareness of disease, cognitive status, mood, functionality, neuropsychiatric symptoms, and caregiver burden. Multivariate regression analyses were conducted to examine the contribution of co-factors. Results: At baseline, PwD self-ratings of QoL were associated with caregiver ratings of PwD QoL (p = 0.001). Caregiver ratings were associated with PwD mood (p = 0.001) and self-rated QoL (p = 0.001). After 1 year, caregiver ratings of PwD QoL changed significantly (p = 0.049, d = -0.27), whereas PwD self-ratings did not (p = 0.89, d = 0.09). PwD awareness of disease changed significantly (p = 0.001) at 1 year, having declined in 25.4% and improved in 12.3% of participants. PwD QoL self-ratings were associated with caregiver ratings (p = 0.001). Caregiver ratings of PwD QoL after 1 year were associated with PwD mood (p = 0.029), self-reported QoL (p = 0.001), and awareness of disease (p = 0.033). Conclusions: The association between self and caregiver ratings of PwD QoL was maintained over 1 year. The primary factors accounting for the change in caregiver ratings were PwD mood and awareness of disease. QoL and cognitive impairment seem to be relatively independent in mild dementia.