Existing data sets to support studies of dementia or significant cognitive impairment and comorbid chronic conditions

Worldwide cohort studies to support healthy ageing research: data availabilities and gaps

BACKGROUND

Population ageing is a transforming demographic force. To support evidence-based efforts for promoting healthy ageing, a summary of data availabilities and gaps to study ageing is needed.

METHOD

Through a multifaceted search strategy, we identified relevant cohort studies worldwide to studying ageing and provided a summary of available pertinent measurements. Following the World Health Organization's definition of healthy ageing, we extracted information on intrinsic capacity domains and sociodemographic, social, and environmental factors.

RESULTS

We identified 287 cohort studies. South America, the Middle East, and Africa had a limited number of cohort studies to study ageing compared to Europe, Oceania, Asia, and North America. Data availabilities of different measures varied substantially by location and study aim. Using the information collected, we developed a web-based Healthy Ageing Toolkit to facilitate healthy ageing research.

CONCLUSIONS

The comprehensive summary of data availability enables timely evidence to contribute to the United Nations Decades of Healthy Ageing goals of promoting healthy ageing for all. Highlighted gaps guide strategies for increased data collection in regions with limited cohort studies. Comprehensive data, encompassing intrinsic capacity and various sociodemographic, social, and environmental factors, is crucial for advancing our understanding of healthy ageing and its underlying pathways.

Associations of liver dysfunction with incident dementia, cognition, and brain structure: A prospective cohort study of 431 699 adults

The relationship between liver dysfunction and dementia has been researched extensively but remains poorly understood. In this study, we investigate the longitudinal and cross-sectional associations between liver function and liver diseases and risk of incident dementia, impaired cognition, and brain structure abnormalities using Cox proportion hazard model and linear regression model. 431 699 participants with a mean of 8.65 (standard deviation [SD] 2.61) years of follow-up were included from the UK Biobank; 5542 all-cause dementia (ACD), 2427 Alzheimer's disease (AD), and 1282 vascular dementia (VaD) cases were documented. We observed that per SD decreases in alanine transaminase (ALT; hazard ratio [HR], 0.917; PFDR  <0.001) and per SD increases in aspartate aminotransferase (AST; HR, 1.048; PFDR  = 0.010), AST to ALT ratio (HR, 1.195; PFDR  <0.001), gamma-glutamyl transpeptidase (GGT; HR, 1.066; PFDR  <0.001), alcoholic liver disease (ALD; HR, 2.872; PFDR  <0.001), and fibrosis and cirrhosis of liver (HR, 2.285; PFDR  = 0.002), being significantly associated with a higher risk of incident ACD. Restricted cubic spline models identified a strong U-shaped association between Alb and AST and incident ACD (Pnonlinear  <0.05). Worse cognition was positively correlated with AST, AST to ALT ratio, direct bilirubin (DBil), and GGT; negatively correlated with ALT, Alb, and total bilirubin (TBil); and ALD and fibrosis and cirrhosis of liver (PFDR  <0.05). Moreover, changes in ALT, GGT, AST to ALT ratio, and ALD were significantly associated with altered cortical and subcortical regions, including hippocampus, amygdala, thalamus, pallidum, and fusiform (PFDR  <0.05). In sensitivity analysis, metabolic dysfunction-associated steatotic liver disease (MASLD) was associated with the risk of ACD and brain subcortical changes. Our findings provide substantial evidence that liver dysfunction may be an important factor for incident dementia. Early intervention in the unhealthy liver may help prevent cognitive impairment and dementia incidence.

Existing Datasets to Study the Impact of Internal Migration on Caregiving Arrangements among Older Adults in China

Massive rural-to-urban migration in China has a significant impact on informal caregiving arrangements among Chinese older adults. To stimulate research on the intersection of migration and caregiving, we conducted an inventory of longitudinal aging survey datasets from mainland China. Large publicly available datasets that included measures related to migration and caregiving were searched and reviewed for eligibility. Key characteristics of each dataset, including study design, sample size, and measures, were extracted. Seven eligible datasets were identified, and five included nationally representative samples. Measures for migration varied across datasets. Some datasets included information on the migration history of older adults, whereas others focused on the migration of adult children. Similarly, caregiving was measured using different questions in each dataset. Caregiving activities were assessed with regard to their type, source, and amount. High-quality datasets exist to support research on migration and caregiving arrangements among Chinese older adults.

Does Rural Living in Early Life Increase the Risk for Reduced Cognitive Functioning in Later Life?

BACKGROUND

There is a robust consensus, most recently articulated in the 2020 Lancet Commission, that the roots of dementia can be traced to early life, and that the path to prevention may start there as well. Indeed, a growing body of research demonstrates that early life disadvantage may influence the risk for later life dementia and cognitive decline. A still understudied risk, however, is early life rural residence, a plausible pathway given related economic and educational disadvantages, as well as associations between later life rural living and lower levels of cognitive functioning.

OBJECTIVE

We aim to examine whether living in rural environments during early life has long term implications for cognitive health in later life.

METHODS

We employed the Wisconsin Longitudinal Study, which tracked 1 in every 3 high school graduates from the class of 1957, from infancy to ∼age 72. The data include a rich array of prospectively collected early life data, unique among existing studies, as well as later life measures of cognitive functioning.

RESULTS

We found a robust relationship between early life rural residence, especially living on a farm, and long-term risk for reduced cognitive performance on recall and fluency tasks. Controls for adolescent cognitive functioning, APOEɛ2 and APOEɛ4, as well as childhood and adult factors, ranging from early life socioeconomic conditions to later life health and rural and farm residency, did not alter the findings.

CONCLUSION

Rural living in early life is an independent risk for lower levels of cognitive functioning in later life.

A Survey of Alzheimer's Disease Early Diagnosis Methods for Cognitive Assessment

Dementia is a syndrome that is characterised by the decline of different cognitive abilities. A high rate of deaths and high cost for detection, treatments, and patients care count amongst its consequences. Although there is no cure for dementia, a timely diagnosis helps in obtaining necessary support, appropriate medication, and maintenance, as far as possible, of engagement in intellectual, social, and physical activities. The early detection of Alzheimer Disease (AD) is considered to be of high importance for improving the quality of life of patients and their families. In particular, Virtual Reality (VR) is an expanding tool that can be used in order to assess cognitive abilities while navigating through a Virtual Environment (VE). The paper summarises common AD screening and diagnosis techniques focusing on the latest approaches that are based on Virtual Environments, behaviour analysis, and emotions recognition, aiming to provide more reliable and non-invasive diagnostics at home or in a clinical environment. Furthermore, different AD diagnosis evaluation methods and metrics are presented and discussed together with an overview of the different datasets.

Cognitive performance in older adults across Europe based on the SHARE database

With ageing mental health issues, as age-related cognitive decline, increase. This study aims to evaluate the prevalence of cognitive impairment among older European adults and to evaluate its association with clinical and sociodemographic variables, using SHARE. Numeracy, temporal orientation, verbal fluency, and memory were the measures used to evaluate cognitive performance. From 44 963 individuals included, mean age was 70.0±9.0 years old and 56.3% were female. Overall prevalence of impairment was of 13.0% (temporal orientation), 24.8% (numeracy), 27.6% (verbal fluency) and 50.5% (memory). Men showed higher impairment prevalence in temporal orientation and memory and lower in numeracy and verbal fluency. Age, fewer years of education, difficulties performing iADLs, physical inactivity, and poor self-perceived health were independently associated with impairment in all cognitive abilities. These results showed the burden of cognitive impairment across Europe. Factors identified as associated should be taken in consideration to develop effective interventions to prevent cognitive decline.

Cardiovascular Risk Factors Are Correlated with Low Cognitive Function among Older Adults Across Europe Based on The SHARE Database

Increased life expectancy is associated with a high prevalence of chronic, non-communicable diseases including cognitive decline and dementia. The purpose of this study was to evaluate the prevalence of cognitive impairment using three cognitive abilities (verbal fluency, numeracy and perceived memory) and their association with cardiovascular risk factors in seniors across Europe. Data from participants in wave 4 of the SHARE (Survey of Health, Ageing, and Retirement in Europe) database was used. Cognitive performance in perceived memory, verbal fluency and numeracy was evaluated using simple tests and a memory complaints questionnaire. Clinical and sociodemographic variables were also studied for potential associations. Standardised prevalence rates of cognitive impairment based on age and gender were calculated by country. The prevalence of cognitive impairment was 28.02% for perceived memory, 27.89% for verbal fluency and 20.75% for numeracy throughout the 16 evaluated countries. Years of education, being a current or former smoker, number of chronic diseases, diabetes or hyperglycemia, heart attack and stroke were all independent variables associated with impairment in the three studied cognitive abilities. We also found independent associations between physical inactivity and verbal fluency and numeracy impairment, as well as hypertension and perceived memory impairment. Lower performance in the evaluated cognitive abilities and higher memory complaints are highly prevalent, have a heterogeneous distribution across Europe, and are associated with multiple factors, most of which are potentially preventable or treatable, especially cardiovascular risk factors.

Secondary Analysis of Existing Datasets for Dementia and Palliative Care Research: High-Value Applications and Key Considerations

OBJECTIVE

To provide a guide to researchers selecting a dataset pertinent to the study of palliative care for people with dementia and to aid readers who seek to critically evaluate a secondary analysis study in this domain.

BACKGROUND

The impact of dementia at end-of-life is large and growing. Secondary dataset analysis can play a critical role in advancing research on palliative care for people with dementia.

METHODS

We conducted a broad search of a variety of resources to: 1. identity datasets that include information germane to dementia and palliative care research; 2. review relevant applications of secondary dataset analysis in the published literature; and 3. explore potential validity and reliability concerns.

RESULTS

We synthesize findings regarding: 1. Methodological approaches for determining the presence of dementia; 2. Inclusion and measurement of key palliative care items as they relate to people with dementia; and 3. Sampling and study design issues, including the role and implications of proxy-respondents. We describe and compare a selection of high-value existing datasets relevant to palliative care and dementia research.

DISCUSSION

While secondary analysis of existing datasets requires consideration of key limitations, it can be a powerful tool for efficiently enhancing knowledge of palliative care needs among people with dementia.

The changing prevalence and incidence of dementia over time - current evidence

Dementia is an increasing focus for policymakers, civil organizations and multidisciplinary researchers. The most recent descriptive epidemiological research into dementia is enabling investigation into how the prevalence and incidence are changing over time. To establish clear trends, such comparisons need to be founded on population-based studies that use similar diagnostic and research methods consistently over time. This narrative Review synthesizes the findings from 14 studies that investigated trends in dementia prevalence (nine studies) and incidence (five studies) from Sweden, Spain, the UK, the Netherlands, France, the USA, Japan and Nigeria. Besides the Japanese study, these studies indicate stable or declining prevalence and incidence of dementia, and some provide evidence of sex-specific changes. No single risk or protective factor has been identified that fully explains the observed trends, but major societal changes and improvements in living conditions, education and healthcare might have favourably influenced physical, mental and cognitive health throughout an individual's life course, and could be responsible for a reduced risk of dementia in later life. Analytical epidemiological approaches combined with translational neuroscientific research could provide a unique opportunity to explore the neuropathology that underlies changing occurrence of dementia in the general population.

Dementia and co-occurring chronic conditions: a systematic literature review to identify what is known and where are the gaps in the evidence?

OBJECTIVE

The challenges posed by people living with multiple chronic conditions are unique for people with dementia and other significant cognitive impairment. There have been recent calls to action to review the existing literature on co-occurring chronic conditions and dementia in order to better understand the effect of cognitive impairment on disease management, mobility, and mortality.

METHODS

This systematic literature review searched PubMed databases through 2011 (updated in 2016) using key constructs of older adults, moderate-to-severe cognitive impairment (both diagnosed and undiagnosed dementia), and chronic conditions. Reviewers assessed papers for eligibility and extracted key data from each included manuscript. An independent expert panel rated the strength and quality of evidence and prioritized gaps for future study.

RESULTS

Four thousand thirty-three articles were identified, of which 147 met criteria for review. We found that moderate-to-severe cognitive impairment increased risks of mortality, was associated with prolonged institutional stays, and decreased function in persons with multiple chronic conditions. There was no relationship between significant cognitive impairment and use of cardiovascular or hypertensive medications for persons with these comorbidities. Prioritized areas for future research include hospitalizations, disease-specific outcomes, diabetes, chronic pain, cardiovascular disease, depression, falls, stroke, and multiple chronic conditions.

CONCLUSIONS

This review summarizes that living with significant cognitive impairment or dementia negatively impacts mortality, institutionalization, and functional outcomes for people living with multiple chronic conditions. Our findings suggest that chronic-disease management interventions will need to address co-occurring cognitive impairment. Copyright © 2017 John Wiley & Sons, Ltd.