Social class and the risk of dementia: A systematic review and meta-analysis of the prospective longitudinal studies

The contribution of household income to rectal cancer patient characteristics, treatment, and outcomes from 2010 to 2020

Background

There is a paucity of recent literature investigating the sole effect of income level on the treatment and survival of patients with rectal cancer.

Methods

We analyzed all cases of rectal cancer in the Rectal Cancer PUF of the NCDB from 2010 to 2020. We utilized the Median Income Quartiles 2016-2020 to define our income levels. The two lower quartiles were combined to create a lower income group, with the upper two quartiles creating the higher income group. The total cohort included 201,329 patients, with 116,843 and 84,486 in the higher and lower income groups, respectively.

Results

Lower income patients were more often black (17 % vs 6 %), lived farther from the nearest hospital (33.5 miles vs 25.7 miles) despite being more likely to live in urban areas (25 % vs 7 %), and had lower levels of private insurance (36 % vs 49 %). They underwent more APRs (17 % vs 14 %) and had a 13 % higher chance of undergoing an open operation (OR 1.13, CI 1.09-1.17). Higher income patients had a 12 % reduction in 90-day (OR 0.88, 95 % CI 0.82-0.96) and overall mortality (OR 0.88, 95 % CI 0.86-0.89).

Conclusions

Clinicians should be aware that lower income patients are often faced with unique challenges that may impact care delivery.

Prevention of dementia using mobile phone applications (PRODEMOS): a multinational, randomised, controlled effectiveness-implementation trial

BACKGROUND

The expected increase of dementia prevalence in the coming decades will mainly be in low-income and middle-income countries and in people with low socioeconomic status in high-income countries. This study aims to reduce dementia risk factors in underserved populations at high-risk using a coach-supported mobile health (mHealth) intervention.

METHODS

This open-label, blinded endpoint, hybrid effectiveness-implementation randomised controlled trial (RCT) investigated whether a coach-supported mHealth intervention can reduce dementia risk in people aged 55-75 years of low socioeconomic status in the UK or from the general population in China with at least two dementia risk factors. The primary effectiveness outcome was change in cardiovascular risk factors, ageing, and incidence of dementia (CAIDE) risk score from baseline to after 12-18 months of intervention. Implementation outcomes were coverage, adoption, sustainability, appropriateness, acceptability, fidelity, feasibility, and costs assessed using a mixed-methods approach. All participants with complete data on the primary outcome, without imputation of missing outcomes were included in the analysis (intention-to-treat principle). This trial is registered with ISRCTN, ISRCTN15986016, and is completed.

FINDINGS

Between Jan 15, 2021, and April 18, 2023, 1488 people (601 male and 887 female) were randomly assigned (734 to intervention and 754 to control), with 1229 (83%) of 1488 available for analysis of the primary effectiveness outcome. After a mean follow-up of 16 months (SD 2·5), the mean CAIDE score improved 0·16 points in the intervention group versus 0·01 in the control group (mean difference -0·16, 95% CI -0·29 to -0·03). 1533 (10%) invited individuals responded; of the intervention participants, 593 (81%) of 734 adopted the intervention and 367 (50%) of 734 continued active participation throughout the study. Perceived appropriateness (85%), acceptability (81%), and fidelity (79%) were good, with fair overall feasibility (53% of intervention participants and 58% of coaches), at low cost. No differences in adverse events between study arms were found.

INTERPRETATION

A coach-supported mHealth intervention is modestly effective in reducing dementia risk factors in those with low socioeconomic status in the UK and any socioeconomic status in China. Implementation is challenging in these populations, but those reached actively participated. Whether this intervention will result in less cognitive decline and dementia requires a larger RCT with long follow-up.

FUNDING

EU Horizon 2020 Research and Innovation Programme and the National Key R&D Programmes of China.

TRANSLATION

For the Mandarin translation of the abstract see Supplementary Materials section.

Exploring the Multifactorial Landscape: Risk Factors for Dementia in a Tertiary Care Setting in Thailand

BACKGROUND

Dementia poses a significant public health challenge worldwide, necessitating a deeper understanding of its risk factors to inform preventive strategies.

METHOD

This retrospective longitudinal study leveraged clinical data from a tertiary care database to investigate the risk factors associated with an incident dementia diagnosis. The study cohort comprised individuals aged 50 years and older. Key variables including age, income, comorbidities such as depressive disorder, osteoporosis, stroke, and metabolic conditions like type 2 diabetes and hypertension were analyzed by using Cox regression analysis.

RESULT

The study cohort included 127,016 adults 50 years and older. The results revealed that advancing age, with individuals aged 70-79 years having a hazard ratio (HR) of 3.9 (95% confidence interval (CI), 2.6-5.8), and those aged 80 years and above having an HR of 11.6 (95% CI, 7.7-17.3), lower income status (patients with no income or occupation had a notably higher risk of dementia diagnosis, with an HR of 2.0 (95% CI, 1.4-2.8)), depressive disorder (HR of 3.3 (95% CI, 3.3-3.7)), osteoporosis (HR of 1.2 (95% CI, 1.1-1.4)), and stroke (HR of 2.5 (95% CI, 2.3-2.7)) were significantly associated with an increased risk of incident dementia. However, no significant associations were observed for type 2 diabetes, hypertension, obesity, or underweight status managed in tertiary care.

CONCLUSION

The findings underscore the importance of considering a wide range of factors in understanding dementia risk and highlight the potential utility of routinely collected clinical data for comprehensive risk assessment. Further investigation into additional variables and multi-center studies may provide deeper insights into the complex interplay of risk factors contributing to dementia onset.

Role of cardiovascular health factors in mediating social inequalities in the incidence of dementia in the UK: two prospective, population-based cohort studies

Background

The contribution of modifiable risk factors to social inequalities in dementia, observed in longitudinal studies, remains unclear. We aimed to quantify the role of cardiovascular health factors, assessed using Life's Essential 8 (LE8) score, in mediating social inequalities in incidence of dementia and, for comparison, in incidence of stroke, coronary heart disease, and mortality.

Methods

In this prospective, population-based cohort study, we collected data from the UK Whitehall II Study and UK Biobank databases. Participants were included if data were available on SEP, outcomes and LE8 (smoking, physical activity, diet, body mass index, blood pressure, fasting blood glucose, lipid levels, sleep duration). The primary outcome was incident dementia and secondary outcomes were stroke, coronary heart disease, and mortality. Outcomes were derived from electronic healthcare records. Socioeconomic position (SEP) was measured by occupation in Whitehall II and education in UK Biobank. Counterfactual mediation analysis was used to quantify the extent to which LE8 score explained the associations of SEP with all outcomes. Analyses involved Cox regression, accelerated failure time models, and linear regression; and were adjusted for age, sex, and ethnicity.

Findings

Between 10.09.1985 and 29.03.1988, a total of 9688 participants (mean age ± SD 44.9 ± 6.0; 67% men) from the Whitehall II study, and between 19.12.2006 and 01.10.2010, 278,215 participants (mean age ± SD 56.0 ± 8.1; 47% men) from the UK Biobank were included. There were 606 and 4649 incident dementia cases over a median (interquartile range) follow-up of 31.7 (31.1-32.7) and 13.5 (12.7-14.1) years respectively in Whitehall II and UK Biobank. In Whitehall II, the hazard ratio was 1.85 [95% CI 1.42, 2.32] for the total effect of SEP on dementia and 1.20 [1.12, 1.28] for the indirect effect via the LE8, the proportion mediated being 36%. In UK Biobank, the total effect of SEP on dementia was 1.65 [1.54, 1.78]; the indirect effect was 1.11 [1.09, 1.12], and the proportion mediated was 24%. The proportions mediated for stroke, coronary heart disease, and mortality were higher, ranging between 34% and 63% in Whitehall II and between 36% and 50% in UK Biobank.

Interpretation

In two well-characterised cohort studies, up to one third of the social inequalities in incidence of dementia was attributable to cardiovascular health factors. Promotion of cardiovascular health in midlife may contribute to reducing social inequalities in risk of dementia, in addition to cardiovascular diseases and all-cause mortality. This study used adult measures of SEP, further research is warranted using lifecourse measures of SEP.

Funding

NIH (RF1AG062553).

Health and Social Care System Preparedness for Dementia Care in Mexico: Current Status and Recommendations to Achieve Optimal Care

In this article, we summarise the findings of the situational analysis of dementia care generated as part of the STRiDE: Strengthening responses to dementia care in developing countries project, including a desk review, a SWOT analysis and views from relevant stakeholders. In addition, the article incorporates the experience of 4 years of work within the STRiDE project of FEDMA, Mexico's Federation of Alzheimer's and other dementias and its allied Associations in presenting specific recommendations to optimise dementia care in the country. All the information gathered brings together a detailed understanding of the current dementia care systems of diagnosis, treatment, and support in general and what is lacking, allowing for the generation of general recommendations to enhance the isolated efforts currently available and amplify their impact, as well as strategies to generate new services currently unavailable, but urgently needed.

Perspective: Promoting Healthy Aging through Nutrition: A Research Centers Collaborative Network Workshop Report

Within 20 y, the number of adults in the United States over the age of 65 y is expected to more than double and the number over age 85 y is expected to more than triple. The risk for most chronic diseases and disabilities increases with age, so this demographic shift carries significant implications for the individual, health care providers, and population health. Strategies that delay or prevent the onset of age-related diseases are becoming increasingly important. Although considerable progress has been made in understanding the contribution of nutrition to healthy aging, it has become increasingly apparent that much remains to be learned, especially because the aging process is highly variable. Most federal nutrition programs and nutrition research studies define all adults over age 65 y as "older" and do not account for physiological and metabolic changes that occur throughout older adulthood that influence nutritional needs. Moreover, the older adult population is becoming more racially and ethnically diverse, so cultural preferences and other social determinants of health need to be considered. The Research Centers Collaborative Network sponsored a 1.5-d multidisciplinary workshop that included sessions on dietary patterns in health and disease, timing and targeting interventions, and health disparities and the social context of diet and food choice. The agenda and presentations can be found at https://www.rccn-aging.org/nutrition-2023-rccn-workshop. Here we summarize the workshop's themes and discussions and highlight research gaps that if filled will considerably advance our understanding of the role of nutrition in healthy aging.

Life course epidemiology and public health

Life course epidemiology aims to study the effect of exposures on health outcomes across the life course from a social, behavioural, and biological perspective. In this Review, we describe how life course epidemiology changes the way the causes of chronic diseases are understood, with the example of hypertension, breast cancer, and dementia, and how it guides prevention strategies. Life course epidemiology uses complex methods for the analysis of longitudinal, ideally population-based, observational data and takes advantage of new approaches for causal inference. It informs primordial prevention, the prevention of exposure to risk factors, from an eco-social and life course perspective in which health and disease are conceived as the results of complex interactions between biological endowment, health behaviours, social networks, family influences, and socioeconomic conditions across the life course. More broadly, life course epidemiology guides population-based and high-risk prevention strategies for chronic diseases from the prenatal period to old age, contributing to evidence-based and data-informed public health actions. In this Review, we assess the contribution of life course epidemiology to public health and reflect on current and future challenges for this field and its integration into policy making.

Association of socioeconomic status and poststroke cognitive function: A systematic review and meta-analysis

BACKGROUND

Stroke survivors are at high risk of coping with cognitive problems after stroke. In recent decades, the relationship between socioeconomic status (SES) and health-related outcomes has been a topic of considerable interest. Learning more about the potential impact of SES on poststroke cognitive dysfunction is of great importance.

OBJECTIVE

The purpose of this systematic review and meta-analysis was to summarize the association between SES and poststroke cognitive function by quantifying the effect sizes of the existing studies.

METHOD

We searched studies from PubMed, Ovid, Embase, Cochrane, Scopus, and PsychINFO up to January 30th 2024 and the references of relevant reviews. Studies reporting the risk of poststroke cognitive dysfunction as assessed by categorized SES indicators were included. The Newcastle-Ottawa scale and the Agency for Healthcare Research and Quality were used to evaluate the study quality. Meta-analyses using fixed-effect models or random-effect models based on study heterogeneity were performed to estimate the influence of SES on cognitive function after stroke, followed by subgroup analyses stratified by study characteristics.

RESULTS

Thirty-four studies were eligible for this systematic review and meta-analysis. Of which, 19 studies reported poststroke cognitive impairment (PSCI) as the outcome, 13 reported poststroke dementia (PSD), one reported both PSCI and PSD, and one reported vascular cognitive impairment no dementia. The findings showed that individuals with lower SES levels had a higher risk of combined poststroke cognitive dysfunction (odds ratio (OR) = 1.91, 95% confidence interval (CI) = 1.59-2.29), PSCI (OR = 2.09, 95% CI = 1.57-2.78), and PSD (OR = 1.95, 95% CI = 1.48-2.57). Subgroup analyses stratified by SES indicators demonstrated the protective effects of education and occupation against the diagnoses of combined poststroke cognitive dysfunction, PSCI, and PSD.

CONCLUSIONS

Stroke survivors belonging to a low SES are at high risk of poststroke cognitive dysfunction. Our findings add evidence for public health strategies to reduce the risk of poststroke cognitive dysfunction by reducing SES inequalities.

Factors influencing the use of natural health products, in particular for concentration and cognition in Germany

BACKGROUND

Natural health products (NHP) are an important part of the healthcare system. They are mainly non-prescription and sold over the counter, which requires active decision making by the consumer. Within the framework of the Complementary and Alternative Healthcare Model, this study aims to identify factors that influence NHP usage, in particular related to concentration and cognition (CC), a topic that concerns all ages and social classes within the population.

METHODS

Data were collected by means of a representative online survey (n = 1,707) in Germany in April 2022. Three user groups were defined: NHPCC users, who used NHP for CC (12 month prevalence); nCC-NHP users, who used NHP but not for CC indications (12 month prevalence); and past NHP users, who have used NHP but not within the previous 12 months. Independent influencing variables were categorized into predisposing, enabling, need, and health service use factors. Data were analyzed with descriptive statistics, inferential statistics, and binary logistic regression models to compare NHPCC users to nCC-NHP users (model 1) and to past NHP users (model 2).

RESULTS

A higher share of NHPCC and nCC-NHP users compared to past NHP users were women, self-medicated with NHP, and used information about NHP provided by health professionals or on product. Their openness-to-change value orientation was more pronounced than of past users. Compared to nCC-NHP and past NHP users, the probability of being an NHPCC user increased if an individual had more difficulties in daily attention and memory performance, made use of health professionals and literature to seek information about NHP, and used NHP for health support and illness prevention. Additionally, a female gender, NHP self-medication, and having higher values of self-transcendence were significant indicators for NHPCC usage compared to past NHP usage.

CONCLUSION

NHP manufacturers, health professionals, and policymakers should be aware of the factors that lead to NHP consumption decisions and consider them in the development and optimization of healthcare strategies as well as in the marketing and communication strategies of companies producing NHP, in particular for CC. The current study can contribute to characterizing the target groups and to defining the aims and communication channels of such campaigns.

Pathways explaining racial/ethnic and socio-economic disparities in dementia incidence: the UK Biobank study

BACKGROUND

Pathways explaining racial/ethnic disparities in dementia risk are under-evaluated.

METHODS

We examine those disparities and their related pathways among UK Biobank study respondents (50-74 y, N = 323,483; 3.6% non-White minorities) using a series of Cox proportional hazards and generalized structural equations models (GSEM).

RESULTS

After ≤15 years, 5,491 all-cause dementia cases were diagnosed. Racial minority status (RACE_ETHN, Non-White vs. White) increased dementia risk by 24% (HR = 1.24, 95% CI: 1.07-1.45, P = 0.005), an association attenuated by socio-economic status (SES), (HR = 1.12, 95% CI: 0.96-1.31). Total race-dementia effect was mediated through both SES and Life's Essential 8 lifestyle sub-score (LE8LIFESTYLE), combining diet, smoking, physical activity, and sleep factors. SES was inversely related to dementia risk (HR = 0.69, 95% CI: 0.67, 0.72, P < 0.001). Pathways explaining excess dementia risk among racial minorities included 'RACE_ETHN(-) → SES(-) → DEMENTIA', 'RACE_ETHN(-) → SES(-) → Poor cognitive performance, COGN(+) → DEMENTIA' and 'RACE_ETHN(-) → SES(+) → LE8LIFESTYLE(-) → DEMENTIA'.

CONCLUSIONS

Pending future interventions, lifestyle factors including diet, smoking, physical activity, and sleep are crucial for reducing racial and socio-economic disparities in dementia.

Age and cause-of-death contributions to educational inequalities in life expectancy and lifespan variation in a low-mortality country: A cross-sectional study of 1.67 million deaths in Spain (2016-19)

BACKGROUND

We aim to assess the age- and cause-specific contributions to differences in life expectancy and lifespan variation between the high- and low-educated groups in Spain.

METHODS

We use sex-, age-, education- and cause-specific mortality and population data for individuals aged 30 and over for 2016-19 in Spain. We estimated life expectancies, and standard deviations of the age-at-death distribution (lifespan variation), and we disentangled the contribution of age-causes of death to educational differences in both indicators.

FINDINGS

Life expectancy at age 30 was higher for high-educated groups compared to low-educated groups, 5.5 years for males and 3.0 years for females. Lifespan variation was higher for low-educated groups compared to high-educated groups, 2.9 years for males and 2.2 years for females. The main contributors to the life expectancy gaps in males were lung cancer (0.58 years) and ischaemic heart diseases (0.42 years), and in females were other cardiovascular causes (0.26 years), and ischaemic heart diseases (0.22 years). The main contributors to the lifespan variation gaps were in males lung cancer (-0.25 years) and ischaemic heart diseases (-0.22 years), while in females were other neoplasms and other diseases of the nervous system.

INTERPRETATION

Whereas behavioural causes are more important in explaining educational inequalities in mortality among men, ageing-related causes of death seem more important among women. Attempts at narrowing socioeconomic gaps in mortality may benefit from applying gender-specific preventive policy measures.

Gender inequalities as contributors to dementia in Latin America and the Caribbean: what factors are missing from research?

The current knowledge of modifiable risk factors for dementia comes mainly from high-income countries. In Latin America and Caribbean countries, where the burden of gender and socioeconomic inequalities is greater than in high-income countries, the prevalence of dementia is also higher and disease onset is earlier, especially among women, even after adjustments for life expectancy. In this Personal View, we discuss socioeconomic modifiable risk factors for dementia established by previous studies and postulate further harmful and often hidden factors faced by women that might influence the gender-specific timing of onset and general prevalence of dementia. We emphasise some of the effects of gender roles, their direct and indirect effects on dementia, and how they disproportionately impact women. Finally, we highlight the importance of bringing hidden risk factors to open discussion to promote research with high-quality data and to encourage public policies to promote and preserve women's health.