Can Caregivers Independently Rate Cognitive and Behavioral Symptoms in Alzheimer's Disease Patients?: A Longitudinal Analysis

Abstract

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.