Abstract of the Day: Neuropsychological Tests Accurately Predict Conversion to Alzheimer Disease
From the Geriatric Research Unit (Dr. Tierney and C. Yao) and Research Design and Biostatistics (Dr. Kiss), Sunnybrook & Women’s College Health Sciences Centre, Toronto; Department of Family and Community Medicine (Dr. Tierney), University of Toronto; and Department of Epidemiology & Community Medicine (Dr. McDowell), University of Ottawa, Ontario, Canada.
Address correspondence and reprint requests to Dr. Mary C. Tierney, Director, Geriatric Research Unit, A145, Sunnybrook and Women’s College Health Sciences Centre, University of Toronto, 2075 Bayview Avenue, Toronto, Ontario, Canada, M4N 3M5;
Objective: To determine whether neuropsychological tests accurately predict incident Alzheimer disease (AD) after 5 and 10 years in participants of the Canadian Study of Health and Aging (CSHA) who were initially nondemented.
Methods: The CSHA was conducted in three waves: CSHA-1 (1991 to 1992), CSHA-2 (1996 to 1997), and CSHA-3 (2001 to 2002). The 10-year prediction study included those who completed neuropsychological testing at CSHA-1 and received a diagnostic assessment at CSHA-3 (n = 263). The 5-year prediction study included those who completed neuropsychological testing at CSHA-2 and received a diagnostic assessment at CSHA-3 (n = 551). The diagnostic workup for dementia at CSHA-3 was formulated without knowledge of neuropsychological test performance at CSHA-1 or CSHA-2. The authors excluded cases with a baseline diagnosis of dementia or a prior history of any condition likely to affect the brain. Age and education were included in all analyses as covariates.
Results: In the 10-year follow-up study, only one test (short delayed verbal recall) emerged from the forward regression analyses. The model with this test and two covariates was significant, 2 (3) = 31.61, p < 0.0001 (sensitivity = 73%, specificity = 70%). In the 5-year follow-up study, three tests (short delayed verbal recall, animal fluency, and information) emerged from the forward logistic regression analyses. The model was significant, 2 (5) = 91.34, p < 0.0001 (sensitivity = 74%, specificity = 83%). Both models were supported with bootstrapping estimates.
Conclusions: In a large epidemiologic sample of nondemented participants, neuropsychological tests accurately predicted conversion to Alzheimer disease after 5 and 10 years.
Anthony H. Risser
neuroscience | neuropsychology | brain | alzheimer disease