Missing-Data in Epidemiological Studies of Age-Associated Cognitive Decline

1999 ◽  
Vol 47 (11) ◽  
pp. 1380-1381 ◽  
Author(s):  
Mauro Di Bari MD ◽  
Jeff Williamson ◽  
Marco Pahor
Keyword(s):  
Missing Data ◽  
Cognitive Decline ◽  
Epidemiological Studies

scholarly journals DIETARY FACTORS AND COGNITIVE DECLINE

2015 ◽  
pp. 1-12
Author(s):  
P.J. Smith ◽  
J.A. Blumenthal
Keyword(s):  
Fatty Acids ◽  
Cognitive Decline ◽  
Randomized Clinical Trials ◽  
Public Health Problem ◽  
Later Life ◽  
Epidemiological Studies ◽  
Dietary Factors ◽  
B Vitamins ◽  
Important Public Health Problem ◽  
The Impact

Cognitive decline is an increasingly important public health problem, with more than 100 million adults worldwide projected to develop dementia by 2050. Accordingly, there has been an increased interest in preventive strategies that diminish this risk. It has been recognized that lifestyle factors including dietary patterns, may be important in the prevention of cognitive decline and dementia in later life. Several dietary components have been examined, including antioxidants, fatty acids, and B vitamins. In addition, whole dietary eating plans, including the Mediterranean diet (MeDi), and the Dietary Approaches to Stop Hypertension (DASH) diet, with and without weight loss, have become areas of increasing interest. Although prospective epidemiological studies have observed that antioxidants, fatty acids, and B vitamins are associated with better cognitive functioning, randomized clinical trials have generally failed to confirm the value of any specific dietary component in improving neurocognition. Several randomized trials have examined the impact of changing ‘whole’ diets on cognitive outcomes. The MeDi and DASH diets offer promising preliminary results, but data are limited and more research in this area is needed.

scholarly journals Impact of missing data on analysis of postoperative cognitive decline (POCD)

2013 ◽  
Vol 26 (2) ◽  
pp. 71-75 ◽  
Author(s):  
Susan K. DeCrane ◽  
Laura P. Sands ◽  
Kristen Marie Young ◽  
Glen DePalma ◽  
Jacqueline M. Leung
Keyword(s):  
Missing Data ◽  
Cognitive Decline ◽  
Postoperative Cognitive Decline

Performances of Several Approaches Handling Large Amounts of Missing Data in Environmental Epidemiological Studies

2013 ◽  
Vol 2013 (1) ◽  
pp. 5295
Author(s):  
Célina Roda ◽  
Ioannis Nicolis ◽  
Chantal Guihenneuc-Jouyaux ◽  
Isabelle Momas
Keyword(s):  
Missing Data ◽  
Epidemiological Studies

Is benzodiazepine use a risk factor for cognitive decline and dementia? A literature review of epidemiological studies

2004 ◽  
Vol 35 (3) ◽  
pp. 307-315 ◽  
Author(s):  
HELENE VERDOUX ◽  
RAJAA LAGNAOUI ◽  
BERNARD BEGAUD
Keyword(s):  
General Population ◽  
Cognitive Decline ◽  
Epidemiological Studies ◽  
Cognitive Outcome ◽  
Public Health Issue ◽  
Hand Search ◽  
Increased Risk ◽  
Benzodiazepine Use

Background. A major public health issue is to determine whether long-term benzodiazepine use may induce cognitive deficits persisting after withdrawal. The aim of the present review was to examine findings from prospective studies carried out in general population samples exploring whether exposure to benzodiazepines is associated with an increased risk of incident cognitive decline.Method. Using a MEDLINE search and a hand-search of related references in selected papers, we retrieved original studies published in peer-reviewed journals that explored in general population samples the association between benzodiazepine exposure and change in cognitive performance between baseline and follow-up assessment.Results. Six papers met the inclusion criteria. Two studies reported a lower risk of cognitive decline in former or ever users, two found no association whatever the category of user, and three found an increased risk of cognitive decline in benzodiazepine users.Conclusions. The discrepant findings obtained by studies examining the link between benzodiazepine exposure and risk of cognitive decline may be due to methodological differences, especially regarding the definitions of exposure and cognitive outcome. As a large proportion of subjects are exposed to benzodiazepines, a small increase in the risk of cognitive decline may have marked deleterious consequences for the health of the general population. This issue needs to be explored further by pharmaco-epidemiological studies.

scholarly journals Missing data in FFQs: making assumptions about item non-response

2016 ◽  
Vol 20 (6) ◽  
pp. 965-970 ◽  
Author(s):  
Karen E Lamb ◽  
Dana Lee Olstad ◽  
Cattram Nguyen ◽  
Catherine Milte ◽  
Sarah A McNaughton
Keyword(s):  
Missing Data ◽  
Current Practice ◽  
Epidemiological Studies ◽  
Nutritional Epidemiology ◽  
Systematic Evaluation ◽  
Simulation Studies ◽  
Imputation Methods ◽  
Single Imputation ◽  
Mean Imputation ◽  
Large Numbers

AbstractObjectiveFFQs are a popular method of capturing dietary information in epidemiological studies and may be used to derive dietary exposures such as nutrient intake or overall dietary patterns and diet quality. As FFQs can involve large numbers of questions, participants may fail to respond to all questions, leaving researchers to decide how to deal with missing data when deriving intake measures. The aim of the present commentary is to discuss the current practice for dealing with item non-response in FFQs and to propose a research agenda for reporting and handling missing data in FFQs.ResultsSingle imputation techniques, such as zero imputation (assuming no consumption of the item) or mean imputation, are commonly used to deal with item non-response in FFQs. However, single imputation methods make strong assumptions about the missing data mechanism and do not reflect the uncertainty created by the missing data. This can lead to incorrect inference about associations between diet and health outcomes. Although the use of multiple imputation methods in epidemiology has increased, these have seldom been used in the field of nutritional epidemiology to address missing data in FFQs. We discuss methods for dealing with item non-response in FFQs, highlighting the assumptions made under each approach.ConclusionsResearchers analysing FFQs should ensure that missing data are handled appropriately and clearly report how missing data were treated in analyses. Simulation studies are required to enable systematic evaluation of the utility of various methods for handling item non-response in FFQs under different assumptions about the missing data mechanism.

The Significance of Age-Related Androgen Depletion in Cognitive Impairment: A Review

2004 ◽  
Vol 5 (2) ◽  
pp. 166-176
Author(s):  
Melanie S. Burkhardt ◽  
Jonathan K. Foster ◽  
Ralph N. Martins
Keyword(s):  
Cognitive Decline ◽  
Hormonal Treatment ◽  
Hormone Treatment ◽  
Epidemiological Studies ◽  
Age Related ◽  
Age Related Cognitive Decline ◽  
Androgen Depletion ◽  
Potential Interactions ◽  
Considerable Support

AbstractThe potential role of supplementing sex steroids for the prevention and delay of age-related cognitive decline has received a great deal of recent interest. Although the biological plausibility of hormone treatment has received considerable support, clinical studies of cognitive functioning after hormonal treatment in postmenopausal women with and without dementia have produced mixed results. Much less attention has been given to the corresponding role of androgens in men. In order to establish the relevance of hormonal supplementation for men in delaying or preventing cognitive decline, it is of importance to evaluate both adrenal and gonadal contributions to androgen status. Additionally, consideration must also be given to the potential interactions of androgens with risk and protective factors (e.g., apolipoprotein E genotype and education). Here we review experimental and epidemiological studies of the significance of androgens for cognitive function.

scholarly journals Insulin sensitivity predicts cognitive decline in individuals with prediabetes

2020 ◽  
Vol 8 (2) ◽  
pp. e001741
Author(s):  
Caroline Willmann ◽  
Kathrin Brockmann ◽  
Robert Wagner ◽  
Stephanie Kullmann ◽  
Hubert Preissl ◽  
...  
Keyword(s):  
Insulin Resistance ◽  
Insulin Secretion ◽  
Insulin Sensitivity ◽  
Cognitive Decline ◽  
Fixed Effects ◽  
Epidemiological Studies ◽  
Oral Glucose ◽  
Dependent Manner ◽  
Prediabetic State ◽  
Cross Sectional

IntroductionEpidemiological studies indicate an association between type 2 diabetes and cognitive dysfunction that appear to start already in the prediabetic state. Although cross-sectional studies have linked insulin resistance to impaired cognition, the potential predictive value of insulin resistance has not yet been sufficiently studied longitudinally without confounding by overt diabetes (and its pharmacological treatment).Research design and methodsWe investigated longitudinal data from participants of the ‘Tübinger Evaluation of Risk Factors for Early Detection of Neurodegeneration’ Study. Subjects underwent a neurocognitive assessment battery (CERAD Plus battery; Consortium to Establish a Registry for Alzheimer’s Disease) at baseline and followed every 2 years (median follow-up 4.0 Q1–3: 2.2–4.3 years). Subjects within a pre-diabetic glycated hemoglobin range of 5.6%–6.5% underwent 5-point 75 g oral glucose tolerance tests (OGTTs) with assessment of insulin sensitivity and insulin secretion (n=175). Subjects with newly diagnosed diabetes mellitus or with major depressivity (Beck Depression Inventory >20) were excluded (n=15). Data were analyzed by mixed models using sex, age and glycemic trait as fixed effects. Subject and time since first measurement were used as random effects.ResultsInsulin sensitivity was positively associated with the CERAD sum score (higher is better) in a time-dependent manner (p=0.0057). This result is mainly driven by a steeper decrease in the memory domain associated with lower insulin sensitivity (p=0.029). The interaction between age and insulin sensitivity was independent of glycemia (p=0.02). There was also no association between insulin secretion and cognition.ConclusionsInsulin resistance rather than sole elevation of blood glucose predicts cognitive decline, specifically in the memory domain, in persons with prediabetes. Treatments of diabetes that improve insulin sensitivity might therefore have the potential to postpone or even prevent cognitive decline in patients with diabetes.

Issues Related to Using a Short-Form of the Center for Epidemiological Studies–Depression Scale

1998 ◽  
Vol 83 (2) ◽  
pp. 411-421 ◽  
Author(s):  
Carole L. Kimberlin ◽  
Jane F. Pendergast ◽  
Donna H. Berardo ◽  
Lynda C. McKenzie
Keyword(s):  
Missing Data ◽  
Factor Structure ◽  
Short Form ◽  
Depression Scale ◽  
Reliability And Validity ◽  
Epidemiological Studies ◽  
Mail Questionnaire ◽  
Reported Health ◽  
Self Reported Health Status ◽  
Missing Items

The study examined the reliability and validity, including the factor structure, of a 10-item abbreviated version of the Center for Epidemiological Studies–Depression (CES—Depression) scale when administered as part of a mail questionnaire. It also examined patterns of nonresponse to items and the effects of imputation of data for missing items on the factor structure of the inventory. A problem of missing data has been reported even with interview administration of the CES–Depression. Researchers have varied considerably in the amount of imputation used to replace missing datapoints. In this study, factor structures varied when items were imputed. In addition, those subjects with complete data were compared with those with up to two imputed datapoints. Those subjects with imputed data were more likely to be female, have lower functional status scores, lower self-reported health status, more advanced age, and a greater number of depressive symptoms than those with no missing data. While the estimate of coefficient alpha of .78 indicated the inventory was reliable, the effects of missing data on construct validity were problematic.

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