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.
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.
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).
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.