Estimation of bivariate measurements having different change points, with application to cognitive ageing

• Published in: Statistics in medicine Vol. 20; no. 24; pp. 3695 - 3714
• Main Authors: Hall, Charles B., Ying, Jun, Kuo, Lynn, Sliwinski, Martin, Buschke, Herman, Katz, Mindy, Lipton, Richard B.
• Format: Journal Article Conference Proceeding
• Language: English
• Published: Chichester, UK John Wiley & Sons, Ltd 30.12.2001; Wiley
• Subjects: Aged; Aged, 80 and over; Aging - physiology; Alzheimer Disease - pathology; Bayes Theorem; Biological and medical sciences; Cognition - physiology; Computerized, statistical medical data processing and models in biomedicine; Degenerative and inherited degenerative diseases of the nervous system. Leukodystrophies. Prion diseases; Humans; Intelligence - physiology; Likelihood Functions; Longitudinal Studies; Medical sciences; Medical statistics; Memory - physiology; Models, Biological; Neurology; New York City; New York City; Human; Nervous system diseases; Statistical analysis; Alzheimer disease; Age criterion; Change point; Statistics; Waiting time; Cerebral disorder; Statistical method; Symptomatology; Follow up study; Measurement technique; Central nervous system disease; Cognitive attitude; Degenerative disease; Bayes decision; Likelihood function
• ISSN: 0277-6715; 1097-0258
• DOI: 10.1002/sim.1113

Longitudinal studies of ageing make repeated observations of multiple measurements on each subject. Change point models are often used to model longitudinal data. We demonstrate the use of Bayesian and profile likelihood methods to simultaneously estimate different change points in the longitudinal course of two different measurements of cognitive function in subjects in the Bronx Aging Study who developed Alzheimer's disease (AD). Analyses show that accelerated memory decline, as measured by Buschke Selective Reminding, begins between seven and eight years before diagnosis of AD, while decline in performance on speeded tasks as measured by WAIS Performance IQ begins slightly more than two years before diagnosis, significantly after the decline in memory. Copyright © 2001 John Wiley & Sons, Ltd.