The Alzheimer’s Disease Assessment Scale: Modifications That Can Enhance its Use in Future Clinical Trials

1997 ◽  
pp. 407-411 ◽  
Author(s):  
Richard C. Mohs ◽  
Deborah Marin ◽  
Cynthia R. Green ◽  
Kenneth L. Davis
1996 ◽  
Vol 9 (1) ◽  
pp. 39-46 ◽  
Author(s):  
Sheela Talwalker ◽  
John E. Overall ◽  
Mandyam K. Srirama ◽  
Stephen I. Gracon

Factor analysis methodology applied to Alzheimer's Disease Assessment Scale (ADAS) subtest profiles for patients in two large-scale clinical trials of the antidementia drug tacrine yielded three oblique factors interpreted as dysfunctions in memory, language, and praxis. The factor structures confirmed reliable assessment of primary dimensions of cognitive impairment in Alzheimer's disease that the original authors of the ADAS proposed to measure and that correspond well to that of the only previously reported factor analysis of the ADAS-COG. The presence of a strong general factor, supported by stable correlations among the oblique primary factors, justifies the recommendation to continue reliance on the ADAS-COG total score as a primary outcome measure in clinical trials, whereas the factor scores are recommended for evaluation of differential treatment effects on more specific aspects of the general cognitive decline. The stability of correlations across time appears to satisfy a primary requirement for application of repeated measures ANOVA to ADAS-COG total score and factor scores in longitudinal clinical trials.


2021 ◽  
Author(s):  
Sophie A. Bell ◽  
Hannah R. Cohen ◽  
Seonjoo Lee ◽  
Hyun Kim ◽  
Adam Ciarleglio ◽  
...  

ABSTRACTIntroductionAssessment of cognition and everyday function is essential in clinical trials for Alzheimer’s disease (AD). Two novel measures of cognition (No Practice Effects (NPE) cognitive battery and Miami Computerized Functional Assessment Scale (CFAS)) were designed to have robust psychometric properties and reduced practice and ceiling effects. This study aims to evaluate if the NPE and CFAS demonstrate stronger psychometric properties and reduced practice effects compared with established measures, including the Preclinical Alzheimer Cognitive Composite (PACC), Alzheimer’s Disease Assessment Scale-Cognitive Subscale (ADAS-Cog), and Functional Activities Questionnaire (FAQ).MethodsThis parallel group, four-site study will randomize 320 cognitively intact adults aged 60 to 85 years to novel or well-established measures of cognition and function. All participants will receive assessments at baseline (week 0), week 12, and week 52, as well as a brain MRI scan and Apolipoprotein E genetic test at study entry. Analyses will determine psychometric properties of the NPE and CFAS, compare the sensitivity of measures to AD risk markers, and identify cognitive domains within the NPE.DiscussionPractice effects have been a major limitation of Alzheimer’s disease clinical trials that typically assess cognitive changes over serial assessments. Detection of functional impairment in cognitively normal individuals with biomarkers for Alzheimer’s disease requires instruments sensitive to very subtle functional changes. This study is intended to support the validation of two new composite measures, the NPE battery and the CFAS, which may advance clinical testing of interventions for individuals across the spectrum of early stage Alzheimer’s disease.Trial RegistrationNCT03900273


Author(s):  
Wilma G. Rosen ◽  
Richard C. Mohs ◽  
Kenneth L. Davis

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