Clinical Characterization of Alzheimer's Disease: Reliability of 'Age at Onset' and a New Descriptor, 'Age at Shift'

To determine the interrater reliability of clinical descriptors for Alzheimer's disease (AD), we assessed the degree of agree ment among four clinicians who rated 21 patients during a longitudinal study. Despite variability in response patterns, degree of agreement for determining age at onset of dementia was statistically significant (P < 0.005). We also found significant agreement (P < 0.0001) among three clinicians for the clinical descriptor, "age at shift" from questionable to probable AD, according to the National Institutes of Health Consensus Criteria. These data demonstrate that both retro spective and prospective descriptors can be reliably determined in the clinical assessment of AD. (J Geriatr Psychiatry Neurol 1988;1:207-211).Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/68908/2/10.1177_089198878800100404.pd