The Validity of Self-Reported Functional Decline Varies by Disease Severity (P04.205)

Abstract

Objective: We studied the validity of self- versus informant-reported ratings of everyday functional impairment in older adults by 1) examining if differences across raters varied by diagnostic group (normal, early-Mild Cognitive Impairment (MCI), late-MCI, dementia), and 2) whether there were differences in how self- versus informant-rated functional impairment related to objective measures of cognition, disease severity (hippocampal volume) and genetic risk (ApoE4 status). Background Measuring the impact of cognitive impairment on daily life may provide a simple and efficient way to help identify those with MCI or dementia. Additionally, the presence of functional impairment is associated with faster subsequent cognitive decline. However, it is unclear to what degree self-reported everyday function is accurate. Design/Methods: Participants were part of the Alzheimer9s Disease Neuroimaging Initiative (ADNI). Everyday function was measured using the Everyday Cognition questionnaire (ECog), which was completed by participants and their informants. Results: Differences between raters varied by diagnostic group: participants with dementia rated themselves as less functionally impaired compared to informant ratings; conversely, normals and early-MCI participants rated themselves as more impaired compared to informant ratings. There was no difference in self- vs. informant-reported functional impairment in the late-MCI group. In the sample as a whole, informant-based ECog scores were strongly associated with objective neuropsychological scores (rs = .41-.60), and were related to genetic status and hippocampal volume. Self-report ECog scores were less strongly related to neuropsychological performance (rs = .19-.30) and were not significantly associated with ApoE4 status or hippocampal volume. Conclusions: Older adults with early and late MCI do not appear to underestimate their level of functional impairment compared to informant ratings, whereas individuals with dementia do underestimate their functional impairment. However, as a whole, informant ratings show closer agreement with neuropsychological performance and to other measures of disease including genetic risk for AD and hippocampal atrophy. Supported by: Data collection and sharing for this project was funded by the Alzheimer9s Disease Neuroimaging Initiative (ADNI) (National Institutes of Health Grant U01 AG024904). ADNI is funded by the National Institute on Aging, the National Institute of Biomedical Imaging and Bioengineering, and through generous contributions from the following: Abbott; Alzheimer9s Association; Alzheimer9s Drug Discovery Foundation; Amorfix Life Sciences Ltd.; AstraZeneca; Bayer HealthCare; BioClinica, Inc.; Biogen Idec Inc.; Bristol-Myers Squibb Company; Eisai Inc.; Elan Pharmaceuticals Inc.; Eli Lilly and Company; F. Hoffmann-La Roche Ltd and its affiliated company Genentech, Inc.; GE Healthcare; Innogenetics, N.V.; Janssen Alzheimer Immunotherapy Research & Development, LLC.; Johnson & Johnson Pharmaceutical Research & Development LLC.; Medpace, Inc.; Merck & Co., Inc.; Meso Scale Diagnostics, LLC.; Novartis Pharmaceuticals Corporation; Pfizer Inc.; Servier; Synarc Inc.; and Takeda Pharmaceutical Company. The Canadian Institutes of Health Research is providing funds to support ADNI clinical sites in Canada. Private sector contributions are facilitated by the Foundation for the National Institutes of Health (www.fnih.org). The grantee organization is the Northern California Institute for Research and Education, and the study is coordinated by the Alzheimer9s Disease Cooperative Study at the University of California, San Diego. ADNI data are disseminated by the Laboratory for Neuro Imaging at the University of California, Los Angeles. This research was also supported by NIH grants P30 AG010129, K01 AG030514, and the Dana Foundation. Disclosure: Dr. Farias has nothing to disclose. Dr. Saito has nothing to disclose. Dr. Harvey has received personal compensation in an editorial capacity for the Journal of Alzheimer Disease and Associated Disorders. Dr. Aisen has received personal compensation for activities wtih Neurochem, Pfizer, Merck, Roche, Amgen, Medivation, Pamlab, Adlyfe, Eisai, GlaxoSmithKline, Lilly, Daiichi,Elan, Wyeth, Avid, Novartis, Martek, Bristol Myers Squibb, Schering Plough as a consultant. Dr. Aisen holds stock and/or stock options for Medivation.Dr. Aisen has received research support from TransTech Pharma, Pfizer, Baxter, Merck, Lilly, Myriad, Elan and Neurochem. Dr. Petersen has received personal compensation for activities with Pfizer, Inc., Janssen Alzheimer9s Immunotherapy, Elan Pharmaceuticals, and GE Healthcare.