The effect of dementia trends and treatments on longevity and disability: a simulation model based on the MRC Cognitive Function and Ageing Study (MRC CFAS)

Impact of hypertension prevalence trend on mortality and burdens of dementia and disability in England and Wales to 2060: a simulation modelling study

BACKGROUND

Previous estimates of the impact of public health interventions targeting hypertension usually focus on one health outcome. This study aims to consider the effects of change in future hypertension prevalence on mortality, dementia, and disability simultaneously.

METHODS

We modelled three plausible scenarios based on observed trends of hypertension prevalence from 2003 to 2017 in England: observed trends continue (baseline scenario); 2017 prevalence remains unchanged; and 2017 prevalence decreases by 50% by 2060. We used a probabilistic Markov model to integrate calendar trends in incidence of cardiovascular disease, dementia, disability, and mortality to forecast their future occurrence in the population of England and Wales. Assuming the hypertension prevalence trend modifies health transition probabilities, we compared mortality outcomes and the burden of dementia and disability to 2060 for the scenarios.

FINDINGS

If the decline in hypertension prevalence stops, there would be a slight increase in the number of additional deaths to 2060 (22·9 [95% uncertainty interval 19·0-26·6] more deaths per 100 000 population), although the burdens of disability and dementia in absolute terms would change little. Alternatively, if the downward hypertension prevalence trend accelerates (with prevalence falling by 50% between 2017 and 2060), there would be a modest additional reduction in deaths (57·0 [50·4-63·5] fewer deaths per 100 000 population), a small increase in dementia burden (9·0 [5·1-13·2] more cases per 100 000 population), no significant effect on disability burden, and an 8% gain in healthy life expectancy at age 65 years from 2020 to 2060 (5·3 years vs 4·9 years) compared with the baseline scenario.

INTERPRETATION

The major future impact of alternative hypertension prevention strategies appears to be on future life expectancy. The salutary effect of lower population blood pressure distribution on incidence of dementia and disability might not offset expansion of the susceptible population due to reduced mortality.

FUNDING

British Heart Foundation and UK Economic and Social Research Council.

Effects of Supplementation with Folic Acid and Its Combinations with Other Nutrients on Cognitive Impairment and Alzheimer's Disease: A Narrative Review

Cognitive impairment and Alzheimer's Disease, among other cognitive dysfunctions, has been recognized as a major public health problem. Folic acid is a well-known essential nutrient whose deficiency has been linked to neurocognitive dysfunctions, owing to hyperhomocysteinemia, an independent risk factor for cardio- and cerebrovascular diseases, including cognitive impairment, Alzheimer's Disease, and vascular dementia. However, to date, there is certain controversy about the efficacy of vitamin supplementation in patients with these pathologies. Therefore, we have reviewed the available dietary intervention studies based on folic acid, either alone or in combination with different vitamins or nutrients into the progression of Alzheimer's Disease and Cognitive impairment, highlighting the cognition and biochemical markers employed for the evaluation of the disease progression. Undeniably, the compiled information supports the potential benefits of vitamin supplementation in these pathologies, especially relevant to the aging process and quality of life, although more research is urgently needed to confirm these positive findings.

Associations of Awareness of Age-Related Change With Emotional and Physical Well-being: A Systematic Review and Meta-analysis

Background and Objectives

This systematic review aimed to synthesize and quantify the associations of awareness of age-related change (AARC) with emotional well-being, physical well-being, and cognitive functioning.

Research Design and Methods

We conducted a systematic review with a correlational random effects meta-analysis. We included quantitative studies, published from January 1, 2009 to October 3, 2018, exploring associations between AARC and one or more of the following outcomes: emotional well-being, physical well-being, and cognitive functioning. We assessed heterogeneity (I²) and publication bias.

Results

We included 12 studies in the review, 9 exploring the association between AARC and emotional well-being and 11 exploring the association between AARC and physical well-being. No study explored the association between AARC and cognitive functioning. Six articles were included in the meta-analysis. We found a moderate association between a higher level of AARC gains and better emotional well-being (r = .33; 95% CI 0.18, 0.47; p <.001; I² = 76.01) and between a higher level of AARC losses and poorer emotional (r = −.31; 95% CI −0.38, −0.24; p < .001; I² = 0.00) and physical well-being (r = −.38; 95% CI −0.51, −0.24; p < .001; I² = 83.48). We found a negligible association between AARC gains and physical well-being (r = .08; 95% CI 0.02, 0.14; p < .122; I² = 0.00). Studies were of medium to high methodological quality.

Discussion and Implications

There is some indication that AARC gains and losses can play a role in emotional well-being and that AARC losses are associated with physical well-being. However, the number of included studies is limited and there was some indication of heterogeneity.

PROSPERO Registration

CRD42018111472.

The impact of dementia on service use by individuals with a comorbid health condition: a comparison of two cross-sectional analyses conducted approximately 10 years apart

BACKGROUND

The presence of concomitant medical conditions in people with dementia is common. Dementia may be related to differential use of health, social and informal care.

METHODS

Data from two large UK population-based studies (CFAS I & II) of adults aged 65 years and older were analysed using logistic regression for binary outcomes and Poisson regression for count outcomes to look at differences in non-dementia service use by those with dementia and a health condition in comparison to those with the health condition alone.

RESULTS

A total of 1619 individuals from CFAS I and 3805 individuals from CFAS II over the age of 75 years were included in this analysis. The presence of dementia and either stroke, diabetes or visual impairment tended to increase the likelihood of a range of different services being used over having any of the health conditions alone. There has been a shift to the use of unpaid care over time. There is now increased use of unpaid care from friends and family by those with dementia and another health condition in comparison to the health condition alone.

CONCLUSIONS

Either due to the decrease in care home spaces or affordability, people with dementia are now relying on unpaid care more than people with other long-term health conditions.

Trends in the use of care among people aged 65–85 with cognitive impairment in the Netherlands

Observation of long-term trends within countries is needed to increase insight into how policy initiatives are reflected in the use of care over time in addition to individual determinants of care use. In the past decades, Dutch care policies have favoured homecare and reduced the availability of institutional care which extended the care responsibilities of formal and informal care-givers at home. This study investigates the changes in the use of informal and formal homecare, community services and residential care among cognitively impaired older adults over time in the Netherlands. In addition, of special interest here are the associations of the presence of a spouse, other family members or social network with care use, and the interdependency between the use of different types of care. The study employs the Longitudinal Aging Study Amsterdam (LASA) covering the years 1992–2012, analysed with generalised estimating equations. The data consisted of 1,022 observations gathered from 813 respondents aged 65–85. The respondents were cognitively impaired according to the age- and education-standardised Mini-Mental State Examination score. The analyses took into account several individual determinants of care use. The use of informal care and residential care decreased while the use of formal homecare and community services remained the same. Simultaneously, the proportion of those who did not use the studied care types increased. The contribution of partners in informal care decreased. Informal care and formal homecare use increasingly became complementary services. The findings suggest that the decreases in informal care and residential care have not been replaced by other types of care, as reflected in the increased number of persons receiving no care. Care policies should not rely excessively on the availability of informal help and should guarantee adequate formal help, especially for those in high need.

Early detection of dementia: The knowledge and attitudes of primary care physicians in Hong Kong

Background

Dementia affects people worldwide and its prevalence is growing. Early detection of dementia by primary care physicians can be beneficial; thus, their knowledge and attitudes about this issue are important.

Objective

To assess primary care physicians’ knowledge and attitudes about the early detection of dementia in Hong Kong.

Methods

This was a mixed methods (qualitative and quantitative) study. Four focus groups with a purposive sample of 31 primary care physicians were interviewed, and a questionnaire-survey was completed and returned by 437 primary care physicians.

Results

Participants all agreed that the early detection of dementia would benefit patients and primary care physicians should be capable of making such diagnoses. Confidence in making an early diagnosis varied; physicians tended to overlook symptoms in the early stages. All agreed that more training is needed at the post-graduate level of medical education.

Conclusions

Participants had positive attitudes towards early detection of dementia; however, their confidence and ability to make an early diagnosis varied.

Projections of multi-morbidity in the older population in England to 2035: estimates from the Population Ageing and Care Simulation (PACSim) model

Background

models projecting future disease burden have focussed on one or two diseases. Little is known on how risk factors of younger cohorts will play out in the future burden of multi-morbidity (two or more concurrent long-term conditions).

Design

a dynamic microsimulation model, the Population Ageing and Care Simulation (PACSim) model, simulates the characteristics (sociodemographic factors, health behaviours, chronic diseases and geriatric conditions) of individuals over the period 2014-2040.

Population

about 303,589 individuals aged 35 years and over (a 1% random sample of the 2014 England population) created from Understanding Society, the English Longitudinal Study of Ageing, and the Cognitive Function and Ageing Study II.

Main outcome measures

the prevalence of, numbers with, and years lived with, chronic diseases, geriatric conditions and multi-morbidity.

Results

between 2015 and 2035, multi-morbidity prevalence is estimated to increase, the proportion with 4+ diseases almost doubling (2015:9.8%; 2035:17.0%) and two-thirds of those with 4+ diseases will have mental ill-health (dementia, depression, cognitive impairment no dementia). Multi-morbidity prevalence in incoming cohorts aged 65-74 years will rise (2015:45.7%; 2035:52.8%). Life expectancy gains (men 3.6 years, women: 2.9 years) will be spent mostly with 4+ diseases (men: 2.4 years, 65.9%; women: 2.5 years, 85.2%), resulting from increased prevalence of rather than longer survival with multi-morbidity.

Conclusions

our findings indicate that over the next 20 years there will be an expansion of morbidity, particularly complex multi-morbidity (4+ diseases). We advocate for a new focus on prevention of, and appropriate and efficient service provision for those with, complex multi-morbidity.

The relationship and mechanism between education and functional health status transition among older persons in China

BACKGROUND

Despite decades of study, debates exist surrounding the relationship between education and functional health status transition among elderly populations. This study aims to add evidence to the debates using China as a case study. Specifically, this study analysed the association of education with functional health status transition and then the mechanism behind that association using the budget constraint relax hypothesis and the efficiency improvement hypothesis among elderly population in China.

METHODS

Based on data from the Chinese Longitudinal Healthy Longevity Surveys from 2008 and 2011, this study focussed on adults aged 65 years and above, with a final sample size of 12,112. A generalised structural equation model was used to analyse the relationship between education and functional health status transition and the mechanism behind that association.

RESULTS

During the three examined years, among elderly adults who were nondisabled at baseline, 53.1% stayed nondisabled, 14.6% became disabled, and 32.3% died; among those disabled in 2008, 8.1% recovered, 21.6% stayed disabled, and 70.3% died. Compared with older adults without any education, those who had attended primary schools had both lower mortality and disability, whereas those who had attended high schools and above only had a lower mortality rate. The budget constraint relax hypothesis and the efficiency improvement hypothesis explained the majority of the relationship between education and transition from non-disability to death, but hardly explained the transition from non-disability to disability. Furthermore, once a person was disabled, education had no significant relationship with functional ability recovery or mortality.

CONCLUSIONS

Attending primary school seems to provide the highest benefit to functional health status transition among older and nondisabled persons in China. Those who attended high schools and above are expected to live a longer life with disability. The mechanism between education and the onset of disability needs more discussion.

Cognitive reserve as a moderator of the negative association between mood and cognition: evidence from a population-representative cohort

BACKGROUND

Cognitive reserve (CR) has been associated with better cognitive function and lower risk of depression in older people, yet it remains unclear whether CR moderates the association between mood and cognition. This study aimed to investigate whether a comprehensive indicator of CR, including education, occupation and engagement in cognitive and social activities, acts as a moderator of this association.

METHODS

This was a cross-sectional study utilising baseline data from the Cognitive Function and Ageing Study II (CFAS II), a large population-based cohort of people aged 65+ in England. Complete data on the measures of CR, mood and cognition were available for 6565 dementia-free individuals. Linear regression models were used to investigate the potential modifying effect of CR on the association between cognition and mood with adjustment for age, sex and missing data.

RESULTS

Levels of CR did moderate the negative association between mood and cognition; the difference in cognition between those with and without a clinical level mood disorder was significantly smaller in the middle (-2.28; 95% confidence interval (CI) -3.65 to -0.90) and higher (-1.30; 95% CI -2.46 to -0.15) CR groups compared with the lower CR group (-4.01; 95% CI -5.53 to -2.49). The individual components of CR did not significantly moderate the negative association between mood and cognition.

CONCLUSION

These results demonstrate that CR, indexed by a composite score based on multiple indicators, can moderate the negative association between lowered mood and cognition, emphasising the importance of continuing to build CR across the lifespan in order to maintain cognitive health.

Forecasted trends in disability and life expectancy in England and Wales up to 2025: a modelling study

Background

Reliable estimation of future trends in life expectancy and the burden of disability is crucial for ageing societies. Previous forecasts have not considered the potential impact of trends in disease incidence. The present prediction model combines population trends in cardiovascular disease, dementia, disability, and mortality to forecast trends in life expectancy and the burden of disability in England and Wales up to 2025.

Methods

We developed and validated the IMPACT-Better Ageing Model—a probabilistic model that tracks the population aged 35–100 years through ten health states characterised by the presence or absence of cardiovascular disease, dementia, disability (difficulty with one or more activities of daily living) or death up to 2025, by use of evidence-based age-specific, sex-specific, and year-specific transition probabilities. As shown in the English Longitudinal Study of Ageing, we projected continuing declines in dementia incidence (2·7% per annum), cardiovascular incidence, and mortality. The model estimates disability prevalence and disabled and disability-free life expectancy by year.

Findings

Between 2015 and 2025, the number of people aged 65 years and older will increase by 19·4% (95% uncertainty interval [UI] 17·7–20·9), from 10·4 million (10·37–10·41 million) to 12·4 million (12·23–12·57 million). The number living with disability will increase by 25·0% (95% UI 21·3–28·2), from 2·25 million (2·24–2·27 million) to 2·81 million (2·72–2·89 million). The age-standardised prevalence of disability among this population will remain constant, at 21·7% (95% UI 21·5–21·8) in 2015 and 21·6% (21·3–21·8) in 2025. Total life expectancy at age 65 years will increase by 1·7 years (95% UI 0·1–3·6), from 20·1 years (19·9–20·3) to 21·8 years (20·2–23·6). Disability-free life expectancy at age 65 years will increase by 1·0 years (95% UI 0·1–1·9), from 15·4 years (15·3–15·5) to 16·4 years (15·5–17·3). However, life expectancy with disability will increase more in relative terms, with an increase of roughly 15% from 2015 (4·7 years, 95% UI 4·6–4·8) to 2025 (5·4 years, 4·7–6·4).

Interpretation

The number of older people with care needs will expand by 25% by 2025, mainly reflecting population ageing rather than an increase in prevalence of disability. Lifespans will increase further in the next decade, but a quarter of life expectancy at age 65 years will involve disability.

Funding

British Heart Foundation.

MODEM: A comprehensive approach to modelling outcome and costs impacts of interventions for dementia. Protocol paper

Background

The MODEM project (A comprehensive approach to MODelling outcome and costs impacts of interventions for DEMentia) explores how changes in arrangements for the future treatment and care of people living with dementia, and support for family and other unpaid carers, could result in better outcomes and more efficient use of resources.

Methods

MODEM starts with a systematic mapping of the literature on effective and (potentially) cost-effective interventions in dementia care. Those findings, as well as data from a cohort, will then be used to model the quality of life and cost impacts of making these evidence-based interventions more widely available in England over the period from now to 2040. Modelling will use a suite of models, combining microsimulation and macrosimulation methods, modelling the costs and outcomes of care, both for an individual over the life-course from the point of dementia diagnosis, and for individuals and England as a whole in a particular year.

Project outputs will include an online Dementia Evidence Toolkit, making evidence summaries and a literature database available free to anyone, papers in academic journals and other written outputs, and a MODEM Legacy Model, which will enable local commissioners of services to apply the model to their own populations.

Discussion

Modelling the effects of evidence-based cost-effective interventions and making this information widely available has the potential to improve the health and quality of life both of people with dementia and their carers, while ensuring that resources are used efficiently.

The influence of smoking, sedentary lifestyle and obesity on cognitive impairment-free life expectancy

BACKGROUND

Smoking, sedentary lifestyle and obesity are risk factors for mortality and dementia. However, their impact on cognitive impairment-free life expectancy (CIFLE)has not previously been estimated.

METHODS

Data were drawn from the DYNOPTA dataset which was derived by harmonizing and pooling common measures from five longitudinal ageing studies. Participants for whom the Mini-Mental State Examination was available were included (N¼8111,48.6% men). Data on education, sex, body mass index, smoking and sedentary lifestyle were collected and mortality data were obtained from Government Records via data linkage.Total life expectancy (LE), CIFLE and years spent with cognitive impairment (CILE)were estimated for each risk factor and total burden of risk factors.

RESULTS

CILE was approximately 2 years for men and 3 years for women, regardless of age. For men and women respectively, reduced LE associated with smoking was 3.82and 5.88 years, associated with obesity was 0.62 and 1.72 years and associated with being sedentary was 2.50 and 2.89 years. Absence of each risk factor was associated with longer LE and CIFLE, but also longer CILE for smoking in women and being sedentary in both sexes. Compared with participants with no risk factors, those with 2þ had shorter CIFLE of up to 3.5 years depending on gender and education level.

CONCLUSIONS

Population level reductions in smoking, sedentary lifestyle and obesity increase longevity and number of years lived without cognitive impairment. Years lived with cognitive impairment may also increase.

Trends in disability in activities of daily living among Chinese older adults, 1997-2006: the China Health and Nutrition Survey

BACKGROUND

A decline in prevalence of late-life disability in activities of daily living (ADLs) has been reported in Western countries. We investigate the time trend of disability in basic ADLs among Chinese older people in 1997-2006, and explore the potential contribution of cardiometabolic diseases to the trend.

METHODS

The study included 7,845 participants (age ≥ 60 years) in the China Health and Nutrition Survey who were examined in 1997, 2000, 2004, and 2006. Data on ADLs were collected through interviews. Disability in basic ADLs was defined as need of assistance or inability to perform at least one of the five self-care activities of bathing, dressing, toileting, feeding, and transferring. Generalized estimating equation models were used to test the time trend in ADL disability and its association with cardiometabolic diseases.

RESULTS

Prevalence of ADL disability decreased from 13.2% in 1997 to 9.9% in 2006; the trend was statistically evident among people aged 60-69 years, women, and rural residents (p trend < .05). From 1997 to 2006, the prevalence of ADL disability decreased at a relative annual rate of 3.1% in total sample; the decline was statistically more evident in young-olds than older-olds, in men than women, and in rural than urban residents. The disabling effect decreased over time for stroke (p trend = .032) and multiple cardiometabolic diseases (p trend = .014).

CONCLUSIONS

The prevalence of disability in basic ADLs among Chinese older adults decreased from 1997 to 2006. Stroke and multiple cardiometabolic diseases appear to become less disabling over time, which may partly contribute to the favorable trend in ADL disability.

Economic and social implications of aging societies

The challenge of global population aging has been brought into sharper focus by the financial crisis of 2008. In particular, growing national debt has drawn government attention to two apparently conflicting priorities: the need to sustain public spending on pensions and health care versus the need to reduce budget deficits. A number of countries are consequently reconsidering their pension and health care provisions, which account for up to 40% of all government spending in advanced economies. Yet population aging is a global phenomenon that will continue to affect all regions of the world. By 2050 there will be the same number of old as young in the world, with 2 billion people aged 60 or over and another 2 billion under age 15, each group accounting for 21% of the world's population.

Remembering the forgotten non-communicable diseases

The forthcoming post-Millennium Development Goals era will bring about new challenges in global health. Low- and middle-income countries will have to contend with a dual burden of infectious and non-communicable diseases (NCDs). Some of these NCDs, such as neoplasms, COPD, cardiovascular diseases and diabetes, cause much health loss worldwide and are already widely recognised as doing so. However, 55% of the global NCD burden arises from other NCDs, which tend to be ignored in terms of premature mortality and quality of life reduction. Here, experts in some of these 'forgotten NCDs' review the clinical impact of these diseases along with the consequences of their ignoring their medical importance, and discuss ways in which they can be given higher global health priority in order to decrease the growing burden of disease and disability.

Potential for primary prevention of Alzheimer's disease: an analysis of population-based data

BACKGROUND

Recent estimates suggesting that over half of Alzheimer's disease burden worldwide might be attributed to potentially modifiable risk factors do not take into account risk-factor non-independence. We aimed to provide specific estimates of preventive potential by accounting for the association between risk factors.

METHODS

Using relative risks from existing meta-analyses, we estimated the population-attributable risk (PAR) of Alzheimer's disease worldwide and in the USA, Europe, and the UK for seven potentially modifiable risk factors that have consistent evidence of an association with the disease (diabetes, midlife hypertension, midlife obesity, physical inactivity, depression, smoking, and low educational attainment). The combined PAR associated with the risk factors was calculated using data from the Health Survey for England 2006 to estimate and adjust for the association between risk factors. The potential of risk factor reduction was assessed by examining the combined effect of relative reductions of 10% and 20% per decade for each of the seven risk factors on projections for Alzheimer's disease cases to 2050.

FINDINGS

Worldwide, the highest estimated PAR was for low educational attainment (19·1%, 95% CI 12·3-25·6). The highest estimated PAR was for physical inactivity in the USA (21·0%, 95% CI 5·8-36·6), Europe (20·3%, 5·6-35·6), and the UK (21·8%, 6·1-37·7). Assuming independence, the combined worldwide PAR for the seven risk factors was 49·4% (95% CI 25·7-68·4), which equates to 16·8 million attributable cases (95% CI 8·7-23·2 million) of 33·9 million cases. However, after adjustment for the association between the risk factors, the estimate reduced to 28·2% (95% CI 14·2-41·5), which equates to 9·6 million attributable cases (95% CI 4·8-14·1 million) of 33·9 million cases. Combined PAR estimates were about 30% for the USA, Europe, and the UK. Assuming a causal relation and intervention at the correct age for prevention, relative reductions of 10% per decade in the prevalence of each of the seven risk factors could reduce the prevalence of Alzheimer's disease in 2050 by 8·3% worldwide.

INTERPRETATION

After accounting for non-independence between risk factors, around a third of Alzheimer's diseases cases worldwide might be attributable to potentially modifiable risk factors. Alzheimer's disease incidence might be reduced through improved access to education and use of effective methods targeted at reducing the prevalence of vascular risk factors (eg, physical inactivity, smoking, midlife hypertension, midlife obesity, and diabetes) and depression.

FUNDING

National Institute for Health Research Collaboration for Leadership in Applied Health Research and Care for Cambridgeshire and Peterborough.

Cohort profile: A prospective cohort study of objective physical and cognitive capability and visual health in an ageing population of men and women in Norfolk (EPIC-Norfolk 3)

The European Prospective Investigation of Cancer (EPIC) is a 10-country collaborative study in which EPIC-Norfolk is one of the UK centres. EPIC-Norfolk examined 25 639 men and women resident in East Anglia (aged 40-79 years), between 1993 and 1997. The EPIC collaboration was set up to examine the dietary determinants of cancer, but the remit in the EPIC-Norfolk cohort was broadened from the outset to include determinants of other health conditions and chronic diseases. EPIC-Norfolk completed a third round of health examinations (EPIC-Norfolk 3 or 3HC) in December 2011, on 8623 participants in the age range 48-92 years. EPIC-Norfolk focused on objective measures of cognitive function, physical capability and visual health, adapting this existing mid-life cohort to the current need to investigate healthy and independent living for ageing societies. With a wealth of longitudinal data and a biobank (including DNA) collected at up to three separate time points, EPIC-Norfolk offers the unique opportunity to investigate the association of lifestyle and biological factors, including genetic exposures, with a range of health outcomes in middle and later life. Information for data access can be found on the study website, details as given in this cohort profile.

Health economic evaluation of treatments for Alzheimer's disease: impact of new diagnostic criteria

The socio-economic impact of Alzheimer's disease (AD) and other dementias is enormous, and the potential economic challenges ahead are clear given the projected future numbers of individuals with these conditions. Because of the high prevalence and cost of dementia, it is very important to assess any intervention from a cost-effectiveness viewpoint. The diagnostic criteria for preclinical AD suggested by the National Institute on Aging and Alzheimer's Association workgroups in combination with the goal of effective disease-modifying treatment (DMT) are, however, a challenge for clinical practice and for the design of clinical trials. Key issues for future cost-effectiveness studies include the following: (i) the consequences for patients if diagnosis is shifted from AD-dementia to predementia states, (ii) bridging the gap between clinical trial populations and patients treated in clinical practice, (iii) translation of clinical trial end-points into measures that are meaningful to patients and policymakers/payers and (iv) how to measure long-term effects. To improve cost-effectiveness studies, long-term population-based data on disease progression, costs and outcomes in clinical practice are needed not only in dementia but also in predementia states. Reliable surrogate end-points in clinical trials that are sensitive to detect effects even in predementia states are also essential as well as robust and validated modelling methods from predementia states that also take into account comorbidities and age. Finally, the ethical consequences of early diagnosis should be considered.

The contribution of diseases to the male-female disability-survival paradox in the very old: results from the Newcastle 85+ study

Background

Explanations for the male-female disability-survival paradox - that woman live longer than men but with more disability - include sex differences in diseases and their impact on disability and death. Less is known about the paradox in the very old. We examine sex differences in the presence and impact of disabling and fatal diseases accounting for the male-female disability-survival paradox in very late life.

Methods

We use data from the Newcastle 85+ Study, a cohort of people born in 1921 and all recruited at age 85 in 2006. Participants underwent a health assessment (HA) at baseline, 18 months, 36 months, 60 months, and a review of their GP records (GPRR) at baseline and 36 months. We used multi-state modelling to assess the impact of specific diseases on disability and death. Disability (measured via ADLs/IADLs) was categorised as no disability (difficulty with 0 activities), or disabled (difficulty with one or more activities). Diseases were ascertained from review of general practice records and cognitive impairment which was defined as an sMMSE of 21 or less (from health assessment).

Results

In participants who had complete HA and GPRR, women had more arthritis (RR = 1.2, 95% CI: 1.1–1.3) and hypertension (RR = 1.2, 95%CI 1.0–1.3), more disability, and were more likely disabled at all follow-ups. From multistate models, women with cerebrovascular disease (HR: 2.6, 95% CI: 2.1–3.4) or respiratory disease (HR: 2.0, 95% CI: 1.4–3.0) were more likely to become disabled than those without but this did not hold for men (sex difference p<0.01). Men were more likely to die from respiratory disease (HR: 2.2, 95% CI: 1.8–2.8) but this did not hold for women (p = 0.002).

Conclusion

The disability-survival paradox was still evident at age 85 and appears due to sex differences in the types of diseases and their impact on the disability pathway.

A two-decade comparison of prevalence of dementia in individuals aged 65 years and older from three geographical areas of England: results of the Cognitive Function and Ageing Study I and II

BACKGROUND

The prevalence of dementia is of interest worldwide. Contemporary estimates are needed to plan for future care provision, but much evidence is decades old. We aimed to investigate whether the prevalence of dementia had changed in the past two decades by repeating the same approach and diagnostic methods as used in the Medical Research Council Cognitive Function and Ageing Study (MRC CFAS) in three of the original study areas in England.

METHODS

Between 1989 and 1994, MRC CFAS investigators did baseline interviews in populations aged 65 years and older in six geographically defined areas in England and Wales. A two stage process, with screening followed by diagnostic assessment, was used to obtain data for algorithmic diagnoses (geriatric mental state-automated geriatric examination for computer assisted taxonomy), which were then used to estimate dementia prevalence. Data from three of these areas--Cambridgeshire, Newcastle, and Nottingham--were selected for CFAS I. Between 2008 and 2011, new fieldwork was done in the same three areas for the CFAS II study. For both CFAS I and II, each area needed to include 2500 individuals aged 65 years and older to provide power for geographical and generational comparison. Sampling was stratified according to age group (65-74 years vs ≥75 years). CFAS II used identical sampling, approach, and diagnostic methods to CFAS I, except that screening and assessement were combined into one stage. Prevalence estimates were calculated using inverse probability weighting methods to adjust for sampling design and non-response. Full likelihood Bayesian models were used to investigate informative non-response.

FINDINGS

7635 people aged 65 years or older were interviewed in CFAS I (9602 approached, 80% response) in Cambridgeshire, Newcastle, and Nottingham, with 1457 being diagnostically assessed. In the same geographical areas, the CFAS II investigators interviewed 7796 individuals (14,242 approached, 242 with limited frailty information, 56% response). Using CFAS I age and sex specific estimates of prevalence in individuals aged 65 years or older, standardised to the 2011 population, 8·3% (884,000) of this population would be expected to have dementia in 2011. However, CFAS II shows that the prevalence is lower (6·5%; 670,000), a decrease of 1·8% (odds ratio for CFAS II vs CFAS I 0·7, 95% CI 0·6-0·9, p=0·003). Sensitivity analyses suggest that these estimates are robust to the change in response.

INTERPRETATION

This study provides further evidence that a cohort effect exists in dementia prevalence. Later-born populations have a lower risk of prevalent dementia than those born earlier in the past century.

FUNDING

UK Medical Research Council.

Planning dementia services: new estimates of current and future prevalence rates of dementia for Ireland

Objectives

The paper provides new estimates of dementia prevalence at a national and local level in Ireland and new projections of future numbers of people with dementia.

Methods

The prevalence of dementia at a national and local level has been calculated by applying European Collaboration on Dementia (EuroCoDe) prevalence rates to data from the Census of Population 2006. The National Disability Survey has been used to estimate the number of people with Down syndrome and dementia. Projections of future numbers of people with dementia have been calculated by applying EuroCoDe prevalence rates to the most recently available population projections from the Central Statistics Office (CSO).

Results

It is estimated that there were 41 740 people with dementia in Ireland in 2006. Estimates show that there are clear regional differences in prevalence of dementia across Ireland, with the largest proportion of people with dementia in the West of Ireland, and the Dublin North Eastern region having the lowest share of dementia. Our best estimate is that there are 700 people with Down syndrome and dementia in Ireland. Applying EuroCoDe prevalence rates to the most recent CSO population projections shows that the prevalence of dementia in Ireland will increase to between 67 493 and 70 000 in 2021 and to between 140 580 and 147 000 in 2041.

Conclusions

Although there are several limitations to these estimates, the data provide timely and useful information for planning effective health and social care services, as well as raising public and professional awareness about dementia at a national level.

A commentary on studies presenting projections of the future prevalence of dementia

BACKGROUND

Population ageing over the first half of this century is likely to lead to dramatic increases in the prevalence of dementia. This will affect all regions of the world, but particularly developing regions. Dementia projections have been used extensively to support policy. It is therefore important these projections are as accurate as possible.

DISCUSSION

In this paper we provide a commentary on studies projecting the future prevalence of dementia for the world or for individual continents. We identify some important limitations of the methods used in published projections and provide recommendations to improve the accuracy of future projections, and allow for the checking of the accuracy of the predictions.

SUMMARY

Accurate projections of dementia incidence, at both the global and local level, are essential for healthcare planners.

Healthy ageing: the role of health care services

The implications of the imminent surge in population ageing for the work of health care services in high-income countries remain unclear. It is widely expected, however, that the prevention and management of chronic disease will increasingly dominate their workload, and that this is likely to require a major shift in the way that care is delivered. This paper argues that the central contribution of health care services to a healthy ageing strategy is to drive improvements in the prevention and management of chronic disease, and it explores some of the implications of this view in the light of evidence mainly from the UK.

Age-related learning deficits can be reversible in honeybees Apis mellifera

Many animals are characterized by declining brain function at advanced ages, including honeybees (Apis mellifera). Variation in honeybee social development, moreover, results in individual differences in the progression of aging that may be accelerated, delayed, and sometimes reversed by changes in behavior. Here, we combine manipulations of social development with a measurement of sensory sensitivity, Pavlovian (associative) learning, and a proteomic technique to study the brain of aged honeybees. First, we confirm that sensory sensitivity can remain intact during aging, and that age-associated learning deficits are specific to bees that forage, a behavior typically expressed after a period of nursing activity. These initial data go beyond previous findings by showing how foragers age in social groups of different age compositions and sizes. Thereafter, we establish that learning ability can recover in aged foragers that revert to nursing tasks. Finally, we use liquid chromatography coupled to tandem mass spectrometry (LC-MS(2)) to describe proteomic differences between central brains, from reverted former foragers that varied in recovery of learning performance, and from nurse bees that varied in learning ability but never foraged. We find that recovery is positively associated with levels of stress response/cellular maintenance proteins in the central brain, while variation in learning before aging is negatively associated with the amounts of metabolic enzymes in the brain tissue. Our work provides the strongest evidence, thus far, for reversibility of learning deficits in aged honeybees, and indicates that recovery-related brain plasticity is connected to cellular stress resilience, maintenance and repair processes.

Oral folic acid and vitamin B-12 supplementation to prevent cognitive decline in community-dwelling older adults with depressive symptoms--the Beyond Ageing Project: a randomized controlled trial

BACKGROUND

Evidence remains unclear as to whether folic acid (FA) and vitamin B-12 supplementation is effective in reducing depressive symptoms.

OBJECTIVES

The objective was to determine whether oral FA + vitamin B-12 supplementation prevented cognitive decline in a cohort of community-dwelling older adults with elevated psychological distress.

DESIGN

A randomized controlled trial (RCT) with a completely crossed 2 × 2 × 2 factorial design comprising daily oral 400 μg FA + 100 μg vitamin B-12 supplementation (compared with placebo), physical activity promotion, and depression literacy with comparator control interventions for reducing depressive symptoms was conducted in 900 adults aged 60-74 y with elevated psychological distress (Kessler Distress 10-Scale; scores >15). The 2-y intervention was delivered in 10 modules via mail with concurrent telephone tracking calls. Main outcome measures examined change in cognitive functioning at 12 and 24 mo by using the Telephone Interview for Cognitive Status-Modified (TICS-M) and the Brief Test of Adult Cognition by Telephone (processing speed); the Informant Questionnaire on Cognitive Decline in the Elderly was administered at 24 mo.

RESULTS

FA + vitamin B-12 improved the TICS-M total (P = 0.032; effect size d = 0.17), TICS-M immediate (P = 0.046; d = 0.15), and TICS-M delayed recall (P = 0.013; effect size d = 0.18) scores at 24 mo in comparison with placebo. No significant changes were evident in orientation, attention, semantic memory, processing speed, or informant reports.

CONCLUSION

Long-term supplementation of daily oral 400 μg FA + 100 μg vitamin B-12 promotes improvement in cognitive functioning after 24 mo, particularly in immediate and delayed memory performance. This trial was registered at clinicaltrials.gov as NCT00214682.

Milk in the diet: good or bad for vascular disease?

CVD still represent the greatest cause of death and disease burden in Europe and there remains uncertainty whether or not diets rich in milk and/or dairy products affect CVD risk. This paper reviews current evidence on this from prospective studies and the role of serum lipids and blood pressure as markers of CVD risk with such diets. Also the potential of animal nutrition-based approaches aimed at reducing CVD risk from consumption of milk and dairy products is outlined. Briefly, the evidence from prospective studies indicates that increased consumption of milk does not result in increased CVD risk and may give some long-term benefits, although few studies relate specifically to cheese and butter and more information on the relationship between milk/dairy product consumption and dementia is needed. Recent data suggest that the SFA in dairy products may be less of a risk factor than previously thought; although this is based on serum cholesterol responses which taken in isolation may be misleading. Milk and some dairy products have counterbalancing effects by reducing blood pressure and possibly BMI control. Despite this, animal nutrition strategies to replace some SFA in milk with cis-MUFA or cis-PUFA are extensive and intuitively beneficial, although this remains largely unproven, especially for milk. There is an urgent need for robust intervention studies to evaluate such milk-fat modifications using holistic markers of CVD risk including central arterial stiffness.

Dairy Products in the Food Chain: Their Impact on Health

Milk is a complex and complete food containing an array of essential nutrients that contribute toward a healthy, balanced diet. Numerous epidemiological studies have revealed that high consumption of milk and dairy products may have protective effects against coronary heart disease (CHD), stroke, diabetes, certain cancers (such as colorectal and bladder cancers), and dementia, although the mechanisms of action are unclear. Despite this epidemiological evidence, milk fatty acid profiles often lead to a negative perception of milk and dairy products. However, altering the fatty acid profile of milk by changing the dairy cow diet is a successful strategy, and intervention studies have shown that this approach may lead to further benefits of milk/dairy consumption. Overall, evidence suggests individuals who consume a greater amount of milk and dairy products have a slightly better health advantage than those who do not consume milk and dairy products.

Future costs of dementia-related long-term care: exploring future scenarios

BACKGROUND

This study explores how the views of a panel of experts on dementia would affect projected long-term care expenditure for older people with dementia in England in the year 2031.

METHODS

A Delphi-style approach was used to gather the views of experts. The projections were carried out using a macro-simulation model of future demand and associated expenditure for long-term care by older people with dementia.

RESULTS

The panel chose statements that suggested a small reduction in the prevalence of dementia over the next fifty years, a freeze in the numbers of people in care homes, and an increase in the qualifications and pay of care assistants who look after older people with dementia. Projections of expenditure on long-term care that seek to capture the views of the panel suggest that future expenditure on long-term care for this group will rise from 0.6% of GDP in 2002 to between 0.82% and 0.96% of GDP in 2031. This range is lower than the projected expenditure of 0.99% of GDP in 2031 obtained under a range of base case assumptions.

CONCLUSIONS

This paper attempts to bridge the gap between qualitative forecasting methods and quantitative future expenditure modelling and has raised a number of important methodological issues. Incorporating the panel's views into projections of future expenditure in long-term care for people with dementia would result in projected expenditure growing more slowly than it would otherwise.