Markers of Cognitive Change in an Aging Population: Early Diagnosis of Dementia to Improve Quality of Life
James E. Galvin, M.D.
Assistant Professor, Neurology, Washington University School of Medicine
Project Overview (Preliminary Information):
As currently planned the grant would have 2 aims: 1. Piloting a "key features" battery to be used as a screening test for dementia 2. Literature review and (very) preliminary (cost) analysis of currently used screening methods. This would also allow us to address the use of radiology in a tangential manner.
Dementia is a significant public health problem that is under-recognized and underdiagnosed. Reliance on objective performance in office-based cognitive tests such as the Mini-Mental Status Exam is hampered by insensitivity to the early stages of dementia and contains biases based on gender, race and educational attainment. Informant-based assessments on the other hand, are unbiased and more sensitive to early cognitive change but are time-consuming. To address the absence of brief but sensitive measures of cognitive change, we undertook a pilot study of individuals enrolled in a longitudinal study of memory and aging to identify clinical variables that appeared to reliably differentiate cognitively normal individuals from those with very mild and mild dementia. Following funding we developed a 55-item battery of informant queries regarding an individual’s cognitive status was derived from a semi-structured interview and a consensus panel of dementia experts. The battery was evaluated with informants for 189 consecutive participants of a longitudinal study of memory and aging and compared with an independently-obtained Clinical Dementia Rating (CDR) rating for the participant. Multiple regression and ROC curves assessed subsets of the items to discriminate between CDR 0 (no dementia) and CDR 0.5 (very mild dementia). The final version (AD8) querying memory, orientation, judgment, and function was administered to an additional sample of 112 CDR 0 and 68 CDR 0.5 participants. Using a cut-off of 2 items endorsed, the area under the curve was 0.834, suggesting good to excellent discrimination; sensitivity = 74% and specificity = 86% (prevalence of 0.38 for very mild dementia). Inclusion of 56 additional individuals with mild to severe dementia (increasing dementia prevalence to 0.53) increased sensitivity to 85% ... Read the full Final Report.