title: Longitudinal studies of cognitive, functional and behavioural change in patients with Alzheimer's disease.
abstract: This paper reviews data on the natural history of symptoms in patients with Alzheimer's disease (AD) and describes some of the problems encountered in analysing longitudinal data in this population. Data on cognition, functional ability and psychiatric or behavioural symptoms have all been obtained from AD patients. Because of attrition, the length of follow-up is not uniform for all patients and neither is the frequency of evaluation. Furthermore, patients enter longitudinal studies with a wide range of symptom severity and longitudinal decline in cognition and function is distinctly non-linear. Behavioural symptoms do not progress regularly in AD but are episodic phenomena not closely related to cognition or function. Strengths and limitations of various analytic techniques used for hypothesis testing with these longitudinal data are described.
authors.affiliation: Department of Psychiatry, Mount Sinai School of Medicine, New York, New York 10029, USA.
authors.forename: R C
authors.initials: RC
authors.lastname: Mohs
authors.forename: J
authors.initials: J
authors.lastname: Schmeidler
authors.forename: M
authors.initials: M
authors.lastname: Aryan
mesh_terms: D000368:Aged; D000544:Alzheimer Disease / Q000145:classification / Q000175:diagnosis* / Q000453:epidemiology; D003072:Cognition Disorders / Q000145:classification / Q000175:diagnosis* / Q000453:epidemiology; D003627:Data Interpretation, Statistical; D006801:Humans; D008137:Longitudinal Studies; D009483:Neuropsychological Tests / Q000706:statistics & numerical data*; D011594:Psychometrics; D015203:Reproducibility of Results; D012920:Social Behavior Disorders / Q000145:classification / Q000175:diagnosis* / Q000453:epidemiology