Abstract
Objective: Intraindividual variability (IIV) –variance in an individuals’ cognitive performance - may be associated with subsequent cognitive decline and/or conversion to dementia in older adults. This novel measure of cognition encompasses two main operationalisations: inconsistency (IIV-I) and dispersion (IIV-D), referring to variance within or across tasks respectively. Each operationalisation can also be measured with or without covariates. This meta-analytic study explores the association between IIV and subsequent cognitive outcomes regardless of operational definitions and measurement approaches. Method: Longitudinal studies (N = 13) that have examined IIV in association with later cognitive decline and/or conversation to MCI/dementia were analysed. The effect of IIV operationalisation was explored. Additional sub group analysis of measurement approaches could not be examined due to the limited number of appropriate studies available for inclusion. Results: Meta-analytic estimates suggest IIV is associated with subsequent cognitive decline and/or conversion to MCI/dementia (r = .20 , 95% CI [.09, .31]) with no significant difference between the two operationalisations observed (Q = 3.41, p = .065). Conclusion: Cognitive IIV, including both IIV-I and IIV-D operationalisations, appears to be associated with subsequent cognitive decline and/or dementia and may offer a novel indicator of incipient dementia in both clinical and research settings.
Original language | English |
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Pages (from-to) | 669–678 |
Number of pages | 10 |
Journal | Neuropsychology |
Volume | 35 |
Issue number | 7 |
DOIs | |
Publication status | Published - Oct 2021 |