TY - JOUR
T1 - Late-life cognitive activity and dementia
AU - Sajeev, Gautam
AU - Weuve, Jennifer
AU - Jackson, John W.
AU - Vanderweele, Tyler J.
AU - Bennett, David A.
AU - Grodstein, Francine
AU - Blacker, Deborah
N1 - Funding Information:
Gautam Sajeev was funded by a Doctoral Foreign Study Award from the Canadian Institutes of Health Research (201110DFS-277667-DRB-217413). Gautam Sajeev, Jennifer Weuve, John W. Jackson, and Deborah Blacker were supported by a grant from Fidelity Biosciences. Jennifer Weuve was also supported by the Alzheimer's Association (NIRG-12-242395) and by the National Institute of Environmental Health Sciences (R21ES020404). Deborah Blacker was also supported by the National Institute on Aging (P50 AG005134). Tyler J. VanderWeele was supported by the National Institute of Environmental Health Sciences (R01 ES017876). David A. Bennett was supported by the National Institute on Aging (P30 AG10161, R01 AG15819, R01 AG17917) and is on the Scientific Advisory Board for Vigorous Minds, Inc.
Publisher Copyright:
© 2016 Wolters Kluwer Health, Inc.
Copyright:
Copyright 2016 Elsevier B.V., All rights reserved.
PY - 2016/9/1
Y1 - 2016/9/1
N2 - Background: Engaging in late-life cognitive activity is often proposed as a strategy to delay or prevent Alzheimer's disease (AD) and other dementias. However, it is unclear to what extent the available evidence supports a causal effect of cognitive activity in dementia prevention. Methods: We systematically searched PubMed and EMBASE through June 2014 to identify peer-reviewed epidemiologic studies of cognitive activity and incidence of AD or all-cause dementia. Eligible articles analyzed data from cohort or nested case-control studies, explicitly defined cognitive activity, evaluated participants for AD or all-cause dementia using clearly defined criteria, and provided effect estimates adjusted for at least age and sex. We describe methodologic issues and biases relevant to interpretation of these studies, and quantify the degree of bias due to confounding and reverse causation required to nullify typically observed associations. Results: We reviewed 12 studies involving 13,939 participants and 1,663 dementia cases, of which 565 were specifically evaluated as AD. Most studies found associations between late-life cognitive activity and lower AD and/or all-cause dementia incidence. Differences in cognitive activity operationalization across studies precluded meta-analysis of effect estimates. Our bias analysis indicated that the observed inverse associations are probably robust to unmeasured confounding, and likely only partially explained by reverse causation. Conclusion: Our systematic review and bias analyses provide support for the hypothesis that late-life cognitive activity offers some reduction in AD and all-cause dementia risk. However, more data are needed to confirm this relationship and on the optimal type, duration, intensity, and timing of that activity.
AB - Background: Engaging in late-life cognitive activity is often proposed as a strategy to delay or prevent Alzheimer's disease (AD) and other dementias. However, it is unclear to what extent the available evidence supports a causal effect of cognitive activity in dementia prevention. Methods: We systematically searched PubMed and EMBASE through June 2014 to identify peer-reviewed epidemiologic studies of cognitive activity and incidence of AD or all-cause dementia. Eligible articles analyzed data from cohort or nested case-control studies, explicitly defined cognitive activity, evaluated participants for AD or all-cause dementia using clearly defined criteria, and provided effect estimates adjusted for at least age and sex. We describe methodologic issues and biases relevant to interpretation of these studies, and quantify the degree of bias due to confounding and reverse causation required to nullify typically observed associations. Results: We reviewed 12 studies involving 13,939 participants and 1,663 dementia cases, of which 565 were specifically evaluated as AD. Most studies found associations between late-life cognitive activity and lower AD and/or all-cause dementia incidence. Differences in cognitive activity operationalization across studies precluded meta-analysis of effect estimates. Our bias analysis indicated that the observed inverse associations are probably robust to unmeasured confounding, and likely only partially explained by reverse causation. Conclusion: Our systematic review and bias analyses provide support for the hypothesis that late-life cognitive activity offers some reduction in AD and all-cause dementia risk. However, more data are needed to confirm this relationship and on the optimal type, duration, intensity, and timing of that activity.
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U2 - 10.1097/EDE.0000000000000513
DO - 10.1097/EDE.0000000000000513
M3 - Review article
C2 - 27227783
AN - SCOPUS:84970023618
VL - 27
SP - 732
EP - 742
JO - Epidemiology
JF - Epidemiology
SN - 1044-3983
IS - 5
ER -