To examine whether informant-based assessments of patients with Alzheimer’s disease (AD) can be used longitudinally to track patient functioning, the authors followed AD patients (N=153) and their caregivers over 1 year with the Relative’s Assessment of Global Symptomatology-Elderly (RAGS-E) and the Alzheimer’s Disease Assessment Scale-Cognitive Subscale (ADASc).
Factor analysis of the RAGS-E yielded two subscales, Cognitive Functioning and Mood Disturbance. The cognitive subscale and ADASc correlated at all visits, whereas the mood subscale did not. After 12 months (n=62), the cognitive scale worsened at a rate similar to the ADASc, suggesting concurrent validity.
Therefore, informant-based measures appear to be reliable and valid methods of identifying cognitive change in AD patients.
Source: Am J Geriatr Psychiatry 1999 Fall;7(4):321-30
PMID: 10521165, UI: 99451209