A multicenter evaluation of new treatment efficacy instruments for Alzheimer's disease clinical trials: overview and general results. The Alzheimer's Disease Cooperative Study.
ABSTRACT Evaluating treatment efficacy in Alzheimer's disease (AD) clinical trials requires optimal assessment methods to determine the extent and clinical meaningfulness of potential therapeutic effects of pharmacologic agents. Development of improved outcome measures for AD clinical trials is a major objective of the Alzheimer's Disease Cooperative Study (ADCS), an NIA-sponsored, multisite clinical trials consortium. The ADCS Instrument Development Project evaluated the sensitivity, reliability and validity of new or improved measures in each of five assessment domains: (a) cognition (immediate and delayed memory, praxis, attention, and executive function); (b) clinical global change; (c) activities of daily living; (d) behavioral symptoms (agitation and other noncognitive symptoms); and (e) cognition in severely impaired patients. A total of 306 English-speaking subjects were enrolled in the study, including AD patients stratified by disease severity and cognitively normal, age-matched elderly subjects. Half were retested at 1 month and 2 months after baseline, and all received 6- and 12-month follow-up assessments. Spanish versions of these new measures are currently being evaluated. The development of this multisite study, the common methods and procedures, and a detailed description of the cohort are provided in this overview article. This multisite project demonstrates the feasibility of a consortium approach to instrument development. We were able to develop new instruments and efficiently evaluate their reliability and sensitivity to longitudinal change by capitalizing on the experience and patient resources of the participating ADCS research sites.
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ABSTRACT: To examine whether informant-based assessments of patients with Alzheimer's disease (AD) can be used longitudinally to track patient functioning, the authors followed AD patients (N=153) and their caregivers over 1 year with the Relative's Assessment of Global Symptomatology-Elderly (RAGS-E) and the Alzheimer's Disease Assessment Scale-Cognitive Subscale (ADASc). Factor analysis of the RAGS-E yielded two subscales, Cognitive Functioning and Mood Disturbance. The cognitive subscale and ADASc correlated at all visits, whereas the mood subscale did not. After 12 months (n=62), the cognitive scale worsened at a rate similar to the ADASc, suggesting concurrent validity. Therefore, informant-based measures appear to be reliable and valid methods of identifying cognitive change in AD patients.American Journal of Geriatric Psychiatry 02/1999; 7(4):321-30. DOI:10.1097/00019442-199911000-00008 · 3.52 Impact Factor
Article: GalantamineDrugs 01/2000; 60(5). DOI:10.2165/00003495-200060050-00008 · 4.13 Impact Factor
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ABSTRACT: Subjects in the preclinical stages of Alzheimer's disease (AD) typically record neuropsychological performance between that of healthy older individuals and demented patients. More specifically, deficits on measures of verbal episodic memory are commonly reported in these patients, while other cognitive functions (e.g. language, praxis and executive function) seem to be spared. A similar neuropsychological profile is observed in elderly subjects with mild cognitive impairment (MCI), a disorder that is attracting increasing research interest. Evidence from lesion and functional imaging studies, as well as volumetric imaging in probable AD and MCI patients, suggests that the cognitive deficits observed in these disorders may be related to medial temporal lobe dysfunction. An issue currently under investigation is whether MCI represents the preclinical stages of AD or a distinct and static cognitive aetiology. In an attempt to address this issue, present investigations are adopting a convergent approach to the detection of preclinical AD, where multiple risk factors are considered when making a diagnosis.Neuroscience & Biobehavioral Reviews 06/2000; 24(3):365-74. DOI:10.1016/S0149-7634(00)00012-9 · 10.28 Impact Factor