To examine dementia severity as determined by the Clinical Dementia Rating (CDR) over time.
Secondary analysis of data from longitudinal studies of aging and dementia.
Alzheimer’s Disease Research Center, where a variety of clinicians contributed CDR ratings during the study.
Adults aged 63 to 83 years with no (CDR 0), very mild (CDR 0.5), or mild (CDR 1) dementia enrolled in the Alzheimer’s Disease Research Center at any time from August 13, 1979, through May 30, 2007.
Main Outcome Measures
Within each CDR group, changes in scores on standardized psychometric tests with time were examined using multiple linear regression analyses. These tests included the Mini-Mental State Examination, Short Blessed Test, Logical Memory IA-Immediate from the Wechsler Memory Scale–Revised, and Blessed Dementia Scale, and a psychometric composite score.
A total of 1768 participants met the inclusion criteria. With time, participants were older, more educated, and more likely to be nonwhite and less likely to be men. Statistically significant change in psychometric test performance with time occurred only within the CDR 1 group for Logical Memory and the psychometric composite, but the degree of change was minimal.
Despite changes in participant characteristics, the CDR demonstrates general stability for assessment of dementia for almost 3 decades.