P3‐223: Correlation of the AD8, an informant‐based dementia screening tool, with amyloid imaging and CSF biomarkers of Alzheimer disease
Year: 2010
Type: article
Study design: Observational Study
Abstract: Screening for Alzheimer's disease (AD), the most common cause of dementia, is generally not recommended because current methods lack sensitivity and specificity. We developed the AD8, a brief informant dementia screening interview validated against comprehensive clinical and cognitive evaluations. Here, we determine whether the AD8 corresponds to changes in AD imaging and CSF biomarkers. We also tested whether informant-based assessments are superior to performance-based dementia screening measurements (e.g. MMSE). 267 research participants were evaluated between December 15, 2005 and January 2, 2009 and completed AD biomarker studies. The sample had a mean age of 75.4y with 15.1y of education; 88.7% were Caucasian and 45.5% were male. The sample was then divided into 2 groups based on their AD8 scores: those that had a negative dementia screening test (AD8 score 0 or 1, n = 137) and those that had a positive dementia screening test (AD8 score 2 or greater, n = 120). Significant differences were seen in PiB binding (p < .001) and CSF biomarkers (p < .001) between individuals with positive and negative AD8 screening tests. Individuals with positive AD8 tests and PiB binding scored in the impaired range on the Wechsler Logical Memory component (mean score 6.9 ± 4.6); individuals with positive AD8 tests and low CSF Aβ42 levels also scored in the impaired range (mean score 7.6 ± 5.3). The AD8 had strong correlations with all AD biomarkers. The area under the curve (AUC) for the AD8 was .732 (95%CI: 064-0.82) for PiB; the AUC for CSF Aβ42 was 0.692 (95%CI: 0.61-0.78), suggesting very good discrimination superior to the MMSE. AD8 scores of 2 or greater corresponded to a biomarker phenotype consistent with AD and to lower performance on tests of episodic memory, supporting an AD diagnosis. Informant-based assessments (AD8) are superior to brief performance-based measures (MMSE) in corresponding to underlying AD pathology. The use of a brief test such as the AD8 may improve strategies for detecting dementia in community settings and in developing countries where biomarkers may not be readily available and may also enrich clinical trial recruitment by increasing the likelihood that participants have underlying biomarker abnormalities that are increasingly becoming required for inclusion.
Source: Alzheimer s & Dementia
Institution: Washington University in St. Louis
Language: English
Subfield: Psychiatry and Mental health
Field: Medicine
Domain: Health Sciences
Open Access status: bronze
OpenAlex ID: W4205423726