Cohort profile: the Cambridge City over-75s Cohort (CC75C)

Insights into the pathological basis of dementia from population-based neuropathology studies

The epidemiological neuropathology perspective of population and community-based studies allows unbiased assessment of the prevalence of various pathologies and their relationships to late-life dementia. In addition, this approach provides complementary insights to conventional case-control studies, which tend to be more representative of a younger clinical cohort. The Cognitive Function and Ageing Study (CFAS) is a longitudinal study of cognitive impairment and frailty in the general United Kingdom population. In this review, we provide an overview of the major findings from CFAS, alongside other studies, which have demonstrated a high prevalence of pathology in the ageing brain, particularly Alzheimer's disease neuropathological change and vascular pathology. Increasing burdens of these pathologies are the major correlates of dementia, especially neurofibrillary tangles, but there is substantial overlap in pathology between those with and without dementia, particularly at intermediate burdens of pathology and also at the oldest ages. Furthermore, additional pathologies such as limbic-predominant age-related TDP-43 encephalopathy, ageing-related tau astrogliopathy and primary age-related tauopathies contribute to late-life dementia. Findings from ageing population-representative studies have implications for the understanding of dementia pathology in the community. The high prevalence of pathology and variable relationship to dementia status has implications for disease definition and indicate a role for modulating factors on cognitive outcome. The complexity of late-life dementia, with mixed pathologies, indicates a need for a better understanding of these processes across the life-course to direct the best research for reducing risk in later life of avoidable clinical dementia syndromes.

The prevalence, correlation, and co-occurrence of neuropathology in old age: harmonisation of 12 measures across six community-based autopsy studies of dementia

BACKGROUND

Population-based autopsy studies provide valuable insights into the causes of dementia but are limited by sample size and restriction to specific populations. Harmonisation across studies increases statistical power and allows meaningful comparisons between studies. We aimed to harmonise neuropathology measures across studies and assess the prevalence, correlation, and co-occurrence of neuropathologies in the ageing population.

METHODS

We combined data from six community-based autopsy cohorts in the US and the UK in a coordinated cross-sectional analysis. Among all decedents aged 80 years or older, we assessed 12 neuropathologies known to be associated with dementia: arteriolosclerosis, atherosclerosis, macroinfarcts, microinfarcts, lacunes, cerebral amyloid angiopathy, Braak neurofibrillary tangle stage, Consortium to Establish a Registry for Alzheimer's disease (CERAD) diffuse plaque score, CERAD neuritic plaque score, hippocampal sclerosis, limbic-predominant age-related TDP-43 encephalopathy neuropathologic change (LATE-NC), and Lewy body pathology. We divided measures into three groups describing level of confidence (low, moderate, and high) in harmonisation. We described the prevalence, correlations, and co-occurrence of neuropathologies.

FINDINGS

The cohorts included 4354 decedents aged 80 years or older with autopsy data. All cohorts included more women than men, with the exception of one study that only included men, and all cohorts included decedents at older ages (range of mean age at death across cohorts 88·0-91·6 years). Measures of Alzheimer's disease neuropathological change, Braak stage and CERAD scores, were in the high confidence category, whereas measures of vascular neuropathologies were in the low (arterioloscerosis, atherosclerosis, cerebral amyloid angiopathy, and lacunes) or moderate (macroinfarcts and microinfarcts) categories. Neuropathology prevalence and co-occurrence was high (2443 [91%] of 2695 participants had more than one of six key neuropathologies and 1106 [41%] of 2695 had three or more). Co-occurrence was strongly but not deterministically associated with dementia status. Vascular and Alzheimer's disease features clustered separately in correlation analyses, and LATE-NC had moderate associations with Alzheimer's disease measures (eg, Braak stage ρ=0·31 [95% CI 0·20-0·42]).

INTERPRETATION

Higher variability and more inconsistency in the measurement of vascular neuropathologies compared with the measurement of Alzheimer's disease neuropathological change suggests the development of new frameworks for the measurement of vascular neuropathologies might be helpful. Results highlight the complexity and multi-morbidity of the brain pathologies that underlie dementia in older adults and suggest that prevention efforts and treatments should be multifaceted.

FUNDING

Gates Ventures.

An exposomic framework to uncover environmental drivers of aging

The exposome, the environmental complement of the genome, is an omics level characterization of an individual's exposures. There is growing interest in uncovering the role of the environment in human health using an exposomic framework that provides a systematic and unbiased analysis of the non-genetic drivers of health and disease. Many environmental toxicants are associated with molecular hallmarks of aging. An exposomic framework has potential to advance understanding of these associations and how modifications to the environment can promote healthy aging in the population. However, few studies have used this framework to study biological aging. We provide an overview of approaches and challenges in using an exposomic framework to investigate environmental drivers of aging. While capturing exposures over a life course is a daunting and expensive task, the use of historical data can be a practical way to approach this research.

Population-Based Studies in Dementia and Ageing Research: A Local and National Experience in Cambridgeshire and the UK

Dementia has been recognised as a key challenge in many ageing societies across the world. Several population-based studies have been developed to investigate dementia and cognitive ageing from perspectives of biology, health, psychology and social sciences. However, there is a need to provide a better understanding of 'contexts', the circumstance where these ageing populations existed, and heterogeneity within and across the populations in different time and places. In this article, we summarise some examples of earlier population-based studies undertaken by our research groups in England and Wales and their contribution to the epidemiology of dementia, neuropathology, cognitive and mental health in older age. We also describe how these studies illustrated variation among ageing populations and changes in their health conditions across time and place. These findings highlight the contribution that population-based studies can make, along with the vital to incorporate contexts in ageing research. A lifecourse approach within social context is needed to integrate life experiences, social circumstances, and multiple dimensions of cognition, functioning, physical health and wellbeing over the ageing process. We also discuss how evidence from population-based studies can support various international initiatives on dementia, healthy ageing and Sustainable Development Goals and facilitate tailored approaches for diverse populations across global societies.

Frailty and neuropathology in relation to dementia status: the Cambridge City over-75s Cohort study

OBJECTIVE

To examine the relative contributions of frailty and neuropathology to dementia expression in a population-based cohort study.

DESIGN

Cross-sectional analysis of observational data.

SETTING

Population-representative clinicopathological cohort study.

PARTICIPANTS

Adults aged 75+ recruited from general practice registries in Cambridge, UK, in 1985.

MEASUREMENTS

A 39-item frailty index and 15-item neuropathological index were used to operationalize frailty and neuropathology, respectively. Dementia status was ascertained by clinical consensus at time of death. Relationships were evaluated using logistic regression models in participants with autopsy records (n = 183). Model fit was assessed using change in deviance. Population attributable fraction for frailty was evaluated in relation to dementia incidence in a representative sample of the survey participants (n = 542).

RESULTS

Participants with autopsy were 92.3 ± 4.6 years at time of death, and mostly women (70%). Average frailty index value at last survey before death was 0.34 ± 0.16. People with dementia (63% of the sample) were frailer, had lower MMSE scores, and a higher burden of neuropathology. Frailty and neuropathological burden were significantly and independently associated with dementia status, without interaction; frailty explained an additional 3% of the variance in the model. Assuming a causal relationship and based on population-attributable fraction analyses, preventing severe frailty (Frailty Index ≥ 0.40) could have avoided 14.2% of dementia cases in this population-based cohort.

CONCLUSIONS

In the very old, frailty contributes to the risk for dementia beyond its relationship with the burden of traditional dementia neuropathologies. Reducing frailty could have important implications for controlling the burden of dementia. Future research on frailty interventions should include dementia risk as a key outcome, public health interventions and policy decisions should consider frailty as a key risk factor for dementia, and biomedical research should focus on elucidating shared mechanisms of frailty and dementia development.

TDP-43 Related Neuropathologies and Phosphorylation State: Associations with Age and Clinical Dementia in the Cambridge City over-75s Cohort

Pathologies associated with the Tar-DNA binding protein 43 KDa (TDP-43) are associated with neurodegenerative diseases and aging. Phosphorylation of cellular proteins is a well-accepted mechanism of biological control and can be associated with disease pathways. Phosphorylation state associated with TDP-43 associated pathology has not been investigated with respect to dementia status in a population representative sample. TDP-43 immunohistochemistry directed toward phosphorylated (TDP-43P) and unphosphorylated (TDP-43U) was assessed in sections of hippocampus and temporal cortex from 222 brains donated to the population representative Cambridge City over-75s Cohort. Relationships between dementia status and age at death for TDP-43 immunoreactive pathologies by phosphorylation state were investigated. TDP-43 pathologies are common in the oldest old in the population and often do not conform to MacKenzie classification. Increasing age is associated with glial (TDP-43P) and neuronal inclusions (TDP-43P and TDP-43U), neurites, and granulovacuolar degeneration (GVD). Dementia status is associated with GVD and glial (TDP-43 P) and neural inclusions (TDP-43 P and U). Dementia severity was associated with glial (TDP-43P) and neuronal inclusions (TDP-43U and TDP-43P), GVD, and neurites. The associations between dementia severity and both glial cytoplasmic inclusions and GVD were independent from other pathologies and TDP-43 neuronal cytoplasmic inclusions. TDP-43 pathology contributes to dementia status and progression in a variety of ways in different phosphorylation states involving both neurons and glia, independently from age and from classic Alzheimer-related pathologies. TDP-43 pathologies as cytoplasmic inclusions in neurons or glia or as GVD contribute independently to dementia.

Longitudinal analysis of the impact of loneliness on cognitive function over a 20-year follow-up

Background: Loneliness and cognitive impairment are both commonly experienced by older old people, but evidence for the association between these has been inconsistent. Moreover, most evidence has been cross-sectional in nature and largely based on studies with relatively young later life age groups rather than 'the oldest old'. We aimed to test the potential impact of loneliness amongst older old people on their cognitive function over a 20-year period.Method: Data were drawn from wave 3 to wave 10 of the Cambridge City over-75s Cohort (CC75C) study. The impact of loneliness on transition between normal and impaired cognitive states was examined by multi-state modelling. The associations between loneliness changes and cognitive function decline were tested by using generalized estimating equation (GEE) with an independent working correlation structure. Missing data were imputed by using multiple imputation chained equations.Results: At wave 3, 713 participants were interviewed, of whom 657 (92%) had Mini-Mental State Examination (MMSE) assessments. Of individuals who had an MMSE score, approximately one quarter reported feeling lonely, and another 16% felt slightly lonely. The prevalence of feeling lonely or slightly lonely varied between waves. Results from multi-state modelling indicated that loneliness was not related to cognitive function transitions, and results from the GEE model showed that loneliness was not significantly associated with cognitive function decline after adjusting for cohort effects, follow-up time, sex, education, and interaction terms for sex, education and time.Conclusions: Loneliness did not exert long-term harmful effects on cognitive function in the oldest old.

Mortality risk of loneliness in the oldest old over a 10-year follow-up

Objective: To investigate the impact of loneliness on all-cause mortality in the oldest old population over a 10-year follow-up.Method: Participants were from the third wave of the Cambridge City over-75s Cohort (CC75C) study, a population-based longitudinal study of older people aged 75 or over. Loneliness was measured two further times. At each wave, participants were asked how often they felt lonely and the answers were divided into three levels: not lonely, slightly lonely and lonely. The relationship between loneliness and all-cause mortality was examined using Cox regression with loneliness as a time-varying predictor. The association was adjusted for socio-demographic factors, number of chronic diseases, functional ability and depression.Results: Seven hundred thirteen participants were seen at wave 3 (out of 2166 at baseline), of whom 665 had data on loneliness. The prevalence of feeling slightly lonely and lonely was 16% and 25%, respectively. Vital status was followed for a further 10 years. A total of 562 participants died during the follow-up. After adjusting for age, sex and other socio-demographic factors, loneliness was associated with a 20% increased risk of mortality (HR: 1.2, 95% CI: 1.0-1.6). The association was disappeared after further adjusting for health conditions and depression (HR: 1.0, 95% CI: 0.8-1.4). Individuals who reported being slightly lonely were not at risk of mortality.Conclusions: The association between loneliness and mortality was fully explained by health conditions, suggesting that in the very old age, health problem is the proximal risk factor for mortality.

The experience of transitions in care in very old age: implications for general practice

BACKGROUND

It can be challenging for general practitioners to support their oldest old patients through the complex process of relocation.

OBJECTIVE

To provide a typology of the experiences of moving in very old age that is clinically useful for practitioners navigating very old people's relocation.

METHODS

Qualitative analysis of data from a mixed-methods UK population-based longitudinal study, Cambridge City over-75s Cohort (CC75C), from Year 21 follow-up onwards. Interviews with participants aged ≥95 years old and proxy informants (Year 21: 44/48, 92%, subsequent attrition all deaths). Thematic analysis of qualitative data available from 26/32 participants who moved before they died.

RESULTS

Individuals who moved voluntarily in with family experienced gratitude, and those who moved into sheltered house or care homes voluntarily had no regrets. One voluntary move into care was experienced with regret, loss and increased isolation as it severed life-long community ties. Regret and loss were key experiences for those making involuntary moves into care, but acceptance, relief and appreciation of increased company were also observed. The key experience of family members was trauma. Establishing connections with people or place ahead of moving, for example through previous respite care, eased moving. A checklist for practitioners based on the resulting typology of relocation is proposed.

CONCLUSIONS

Most of the sample moved into residential care. This study highlights the importance of connections to locality, people and place along with good family relationships as the key facilitators of a healthy transition into care for the oldest old. The proposed checklist may have clinical utility.

Putative risk alleles for LATE-NC with hippocampal sclerosis in population-representative autopsy cohorts

Limbic‐predominant age‐related TAR‐DNA‐binding protein‐43 (TDP‐43) encephalopathy with hippocampal sclerosis pathology (LATE‐NC + HS) is a neurodegenerative disorder characterized by severe hippocampal CA1 neuron loss and TDP‐43‐pathology, leading to cognitive dysfunction and dementia. Polymorphisms in GRN, TMEM106B and ABCC9 are proposed as LATE‐NC + HS risk factors in brain bank collections. To replicate these results in independent population‐representative cohorts, hippocampal sections from brains donated to three such studies (Cambridge City over 75‐Cohort [CC75C], Cognitive Function and Ageing Study [CFAS], and Vantaa 85+ Study) were stained with hematoxylin–eosin (n = 744) and anti‐pTDP‐43 (n = 713), and evaluated for LATE‐NC + HS and TDP‐43 pathology. Single nucleotide polymorphism genotypes in GRN rs5848, TMEM106B rs1990622 and ABCC9 rs704178 were determined. LATE‐NC + HS (n = 58) was significantly associated with the GRN rs5848 genotype (χ²(2) = 20.61, P < 0.001) and T‐allele (χ²(1) = 21.04, P < 0.001), and TMEM106B rs1990622 genotype (Fisher's exact test, P < 0.001) and A‐allele (χ²(1) = 25.75, P < 0.001). No differences in ABCC9 rs704178 genotype or allele frequency were found between LATE‐NC + HS and non‐LATE‐NC + HS neuropathology cases. Dentate gyrus TDP‐43 pathology associated with GRN and TMEM106B variations, but the association with TMEM106B nullified when LATE‐NC + HS cases were excluded. Our results indicate that GRN and TMEM106B are associated with severe loss of CA1 neurons in the aging brain, while ABCC9 was not confirmed as a genetic risk factor for LATE‐NC + HS. The association between TMEM106B and LATE‐NC + HS may be independent of dentate TDP‐43 pathology.

Is loneliness associated with increased health and social care utilisation in the oldest old? Findings from a population-based longitudinal study

OBJECTIVES

The present study aimed to examine the impact of loneliness on health and social care service use in the oldest old over a 7-year follow-up.

DESIGN

Prospective study.

SETTING

UK population-based cohort.

PARTICIPANTS

713 people aged 80 years or older were interviewed at wave 3 of the Cambridge City over-75s Cohort Study. Of these, 665 provided data on loneliness. During 7 years' follow-up, 480 participants left the study, of which 389 due to death. 162 still in the study answered the loneliness question.

MAIN OUTCOME MEASURE

Use of health and social care services, assessed at each wave from wave 3 to wave 5.

RESULTS

At wave 3, of 665 participants who had data on loneliness, about 60% did not feel lonely, 16% felt slightly lonely and 25% felt lonely. Being slightly lonely at wave 3 was associated with a shorter time since last seeing a general practitioner (β=-0.5, 95% CI: -0.8 to -0.2); when examining the association between time-varying loneliness and health and social care usage, being lonely was associated with three times greater likelihood of having contact with community nurses and using meals on wheels services (community nurse contact: incidence rate ratio (IRR)=3.4, 95% CI: 1.4 to 8.7; meals on wheels service use: IRR=2.5, 95% CI: 1.1 to 5.6). No associations between loneliness and other health and social care services use were found.

CONCLUSION

Loneliness was a significant risk factor for certain types of health and social care utilisations, independently of participants' health conditions, in the oldest old. Study findings have several implications, including the need for awareness-raising and prevention of loneliness to be priorities for public health policy and practice.

Lack of associations between modifiable risk factors and dementia in the very old: findings from the Cambridge City over-75s cohort study

OBJECTIVES

To investigate the association between modifiable risk and protective factors and severe cognitive impairment and dementia in the very old. Additionally, the present study tests the predictive validity of the 'LIfestyle for BRAin health' (LIBRA) score, an index developed to assess an individual's dementia prevention potential.

METHOD

Two hundred seventy-eight individuals aged 85 years or older from the Cambridge City over-75s cohort study were followed-up until death. Included risk and protective factors were: diabetes, heart disease, hypertension, depression, smoking, low-to-moderate alcohol use, high cognitive activity, and physical inactivity. Incident severe cognitive impairment was based on the Mini-Mental State Examination (score: 0-17) and incident dementia was based on either post-mortem consensus clinical diagnostic assessments or death certificate data. Logistic regressions were used to test whether individual risk and protective factors and the LIBRA score were associated with severe cognitive impairment or dementia after 18 years follow-up.

RESULTS

None of the risk and protective factors or the LIBRA score was significantly associated with increased risk of severe cognitive impairment or dementia. Sensitivity analyses using a larger sample, longer follow-up period, and stricter cut-offs for prevalent cognitive impairment showed similar results.

CONCLUSION

Associations between well-known midlife risk and protective factors and risk for severe cognitive impairment or dementia might not persist into very old age, in line with suggestions that targeting these factors through lifestyle interventions should start earlier in life.

Review of methodologies of cohort studies of older people

This paper describes a cohort study in terms of its design, the research questions answered by cohort studies, common analytic techniques and the strengths and limitations of this type of study. We also describe the main cohort studies of older populations, many of which are available for secondary data analysis.

Learning from older peoples' reasons for participating in demanding, intensive epidemiological studies: a qualitative study

Background

Recruitment rates of older people in epidemiological studies, although relatively higher than in clinical trials, have declined in recent years. This study aimed to explore motivating factors and concerns among older participants in an intensive epidemiological study (Hertfordshire Sarcopenia Study - HSS) and identify those that could aid future recruitment to epidemiological studies and clinical trials.

Methods

Participants of the HSS fasted overnight and travelled several hours each way to the research facility at an English hospital for extensive diet/lifestyle questionnaires and investigations to assess muscle including blood tests and a muscle biopsy. We conducted semi-structured interviews with 13 participants (ten women) at the research facility in May–October 2015. The interviews were audio-taped, transcribed verbatim, coded and analysed thematically by three researchers.

Results

We identified personal motives for participation (potential health benefit for self and family; curiosity; comparing own fitness to others; socialising). Altruistic motives (benefit for other people; belief in importance of research) were also important. Participants voiced a number of external motives related to the study uniqueness, organisation and safety record; family support; and just ‘being asked’. Anxiety about the biopsy and travel distance were the only concerns and were alleviated by smooth and efficient running of the study.

Conclusions

Personal and altruistic reasons were important motivators for these older people to participate in demanding, intensive research. They valued belonging to a birth cohort with previous research experience, but personal contact with the research team before and after consent provided reassurance, aided recruitment to HSS and could be readily replicated by other researchers.

Any fears or concerns related to certain aspects of a demanding, intensive study should ideally be explored at an early visit to establish a good relationship with the research team.

Dying comfortably in very old age with or without dementia in different care settings - a representative "older old" population study

BACKGROUND

Comfort is frequently ranked important for a good death. Although rising numbers of people are dying in very old age, many with dementia, little is known about symptom control for "older old" people or whether care in different settings enables them to die comfortably. This study aims to examine, in a population-representative sample, associations between factors potentially related to reported comfort during very old people's final illness: physical and cognitive disability, place of care and transitions in their final illness, and place of death.

METHODS

Retrospective analyses linked three data sources for n = 180 deceased study participants (68% women) aged 79-107 in a representative population-based UK study, the Cambridge City over-75s Cohort (CC75C): i) prospective in-vivo dementia diagnoses and cognitive assessments, ii) certified place of death records, iii) data from interviews with relatives/close carers including symptoms and "How comfortable was he/she in his/her final illness?"

RESULTS

In the last year of life 83% were disabled in basic activities, 37% had moderate/severe dementia and 45% minimal/mild dementia or cognitive impairment. Regardless of dementia/cognitive status, three-quarters died following a final illness lasting a week or longer. 37%, 44%, 13% and 7% of the deceased were described as having been "very comfortable", "comfortable", "fairly comfortable" or "uncomfortable" respectively during their final illness, but reported symptoms were common: distress, pain, depression and delirium or confusion each affected 40-50%. For only 10% were no symptoms reported. There were ≥4-fold increased odds of dying comfortably associated with being in a care home during the final illness, dying in a care home, and with staying in place (dying at what death certificates record as "usual address"), whether home or care home, compared with hospital, but no significant association with disability or dementia/cognitive status, regardless of adjustment.

CONCLUSIONS

These findings are consistent with reports that care homes can provide care akin to hospice for the very old and support an approach of supporting residents to stay in their care home or own home if possible. Findings on reported high prevalence of multiple symptoms can inform policy and training to improve older old people's end-of-life care in all settings.

Hippocampal sclerosis, hippocampal neuron loss patterns and TDP-43 in the aged population

Hippocampal neuron loss is a common neuropathological feature in old age with various underlying etiologies. Hippocampal sclerosis of aging (HS-Aging) is neuropathologically characterized by severe CA1 neuronal loss and frequent presence of transactive response DNA-binding protein of 43 kDa (TDP-43) aggregations. Its etiology is unclear and currently no standardized approaches to measure HS-Aging exist. We developed a semi-quantitative protocol, which captures various hippocampal neuron loss patterns, and compared their occurrence in the context of HS-Aging, TDP-43, vascular and tau pathology in 672 brains (TDP-43 staining n = 642/672, 96%) donated for the population-based Cambridge City over-75s Cohort and the Cognitive Function and Ageing Study. HS-Aging was first evaluated independently from the protocol using the most common criteria defined in literature, and then described in detail through examination of neuron loss patterns and associated pathologies. 34 (5%) cases were identified, with a maximum of five pyramidal neurons in each of over half CA1 fields-of-view (x200 magnification), no vascular damage, no neuron loss in CA2-CA4, but consistent TDP-43 neuronal solid inclusions and neurites. We also report focal CA1 neuron loss with vascular pathology to affect predominantly CA1 bordering CA2 (Fisher's exact, P = 0.009), whereas neuron loss in the subicular end of CA1 was associated with TDP-43 inclusions (Fisher's exact, P < 0.001) and high Braak stage (Fisher's exact, P = 0.001). Hippocampal neuron loss in CA4-CA2 was not associated with TDP-43. We conclude that hippocampal neuron loss patterns are associated with different etiologies within CA1, and propose that these patterns can be used to form objective criteria for HS-Aging diagnosis. Finally, based on our results we hypothesize that neuron loss leading to HS-Aging starts from the subicular end of CA1 when it is associated with TDP-43 pathology, and that this neurodegenerative process is likely to be significantly more common than "end-stage" HS-Aging only.

Association of Delirium With Cognitive Decline in Late Life: A Neuropathologic Study of 3 Population-Based Cohort Studies

IMPORTANCE

Delirium is associated with accelerated cognitive decline. The pathologic substrates of this association are not yet known, that is, whether they are the same as those associated with dementia, are independent, or are interrelated.

OBJECTIVE

To examine whether the accelerated cognitive decline observed after delirium is independent of the pathologic processes of classic dementia.

DESIGN, SETTING, AND PARTICIPANTS

Harmonized data from 987 individual brain donors from 3 observational cohort studies with population-based sampling (Vantaa 85+, Cambridge City Over-75s Cohort, Cognitive Function and Ageing Study) performed from January 1, 1985, through December 31, 2011, with a median follow-up of 5.2 years until death, were used in this study. Neuropathologic assessments were performed with investigators masked to clinical data. Data analysis was performed from January 1, 2012, through December 31, 2013. Clinical characteristics of brain donors were not different from the rest of the cohort. Outcome ascertainment was complete given that the participants were brain donors.

EXPOSURES

Delirium (never vs ever) and pathologic burden of neurofibrillary tangles, amyloid plaques, vascular lesions, and Lewy bodies. Effects modeled using random-effects linear regression and interactions between delirium and pathologic burden were assessed.

OUTCOMES

Change in Mini-Mental State Examination (MMSE) scores during the 6 years before death.

RESULTS

There were 987 participants (290 from Vantaa 85+, 241 from the Cambridge City Over-75s Cohort, and 456 from the Cognitive Function and Ageing Study) with neuropathologic data; mean (SD) age at death was 90 (6.4) years, including 682 women (69%). The mean MMSE score 6 years before death was 24.7 points. The 279 individuals with delirium (75% women) had worse initial scores (-2.8 points; 95% CI, -4.5 to -1.0; P < .001). Cognitive decline attributable to delirium was -0.37 MMSE points per year (95% CI, -0.60 to -0.13; P < .001). Decline attributable to the pathologic processes of dementia was -0.39 MMSE points per year (95% CI, -0.57 to -0.22; P < .001). However, the combination of delirium and the pathologic processes of dementia resulted in the greatest decline, in which the interaction contributed an additional -0.16 MMSE points per year (95% CI, -0.29 to -0.03; P = .01). The multiplicative nature of these variables resulted in individuals with delirium and the pathologic processes of dementia declining 0.72 MMSE points per year faster than age-, sex-, and educational level-matched controls.

CONCLUSIONS AND RELEVANCE

Delirium in the presence of the pathologic processes of dementia is associated with accelerated cognitive decline beyond that expected for delirium or the pathologic process itself. These findings suggest that additional unmeasured pathologic processes specifically relate to delirium. Age-related cognitive decline has many contributors, and these findings at the population level support a role for delirium acting independently and multiplicatively to the pathologic processes of classic dementia.

A Novel Examination of Successful Aging Trajectories at the End of Life

Un indice de vieillissement réussi (SA) a été capturé dans une étude de cohorte longitudinale basée sur la population des personnes de 75 ans et plus, qui a été examiné longitudinalement en utilisant la modélisation d’un mélange de croissance (MMC) pour identifier les groupes ayant des trajectoires similaires utilisant la dernière interview complète de personnes décédées et jusqu’à quatre collections de données précédentes avant la mort. MMC a identifié un modèle avec trois classes. Les classes étaient : haut fonctionnement, pas de déclin (HPD); fonctionnement élevé, baisse progressive (HBP); et un faible fonctionnement, fort baisse (FB). Les individus de la classe HPD étaient significativement plus jeunes à la mort, et à la fin de l’examen, se composait de plus d’hommes, et plus susceptibles d’être mariées, comparativement aux individus HBP et FB. Ces résultats démontrent différentes façons dont les individus peuvent éprouver un vieillissement réussi à la fin de vie. Cette étude fournit le cadre pour la recherche future en ce qui concerne les processus du vieillissement pendant toute la vie, avec des implications importantes pour la politique et la pratique.

Healthy aging profile in octogenarians in Brazil

OBJECTIVE

to identify the healthy aging profile in octogenarians in Brazil.

METHOD

this population-based epidemiological study was conducted using household interviews of 335 octogenarians in a Brazilian municipality. The decision-tree model was used to assess the healthy aging profile in relation to the socioeconomic characteristics evaluated at baseline. All of the tests used a p-value < 0.05.

RESULTS

the majority of the 335 participating older adults were women (62.1%), were aged between 80 and 84 years (50.4%), were widowed (53.4%), were illiterate (59.1%), had a monthly income of less than one minimum wage (59.1%), were retired (85.7%), lived with their spouse (63.8%), did not have a caregiver (60.3%), had two or more children (82.7%), and had two or more grandchildren (78.8%). The results indicate three age groups with a healthier aging profile: older adults aged 80 to 84 years (55.6%), older adults aged 85 years and older who are married (64.9%), and older adults aged 85 and older who do not have a partner or a caregiver (54.2%).

CONCLUSION

the healthy aging profile of octogenarians can be explained by age group, marital status, and the presence of a caregiver.

Death and the Oldest Old: Attitudes and Preferences for End-of-Life Care--Qualitative Research within a Population-Based Cohort Study

INTRODUCTION

Increasing longevity means more people will be dying in very old age, but little is known about the preferences of the 'oldest old' regarding their care at the end of life.

AIMS

To understand very old people's preferences regarding care towards the end of life and attitudes towards dying, to inform policy and practice.

METHODS

Qualitative data collection for n = 42 population-based cohort study participants aged 95-101 (88% women, 42% in long-term-care): topic-guided interviews with n = 33 participants and n = 39 proxy informants, most with both (n = 30: 4 jointly + separate interviews for 26 dyads).

RESULTS

Death was a part of life: these very old people mainly live day-to-day. Most were ready to die, reflecting their concerns regarding quality of life, being a nuisance, having nothing to live for and having lived long enough. Contrasting views were rare exceptions but voiced firmly. Most were not worried about death itself, but concerned more about the dying process and impacts on those left behind; a peaceful and pain-free death was a common ideal. Attitudes ranged from not wanting to think about death, through accepting its inevitable approach to longing for its release. Preferring to be made comfortable rather than have life-saving treatment if seriously ill, and wishing to avoid hospital, were commonly expressed views. There was little or no future planning, some consciously choosing not to. Uncertainty hampered end-of-life planning even when death was expected soon. Some stressed circumstances, such as severe dependency and others' likely decision-making roles, would influence choices. Carers found these issues harder to raise but felt they would know their older relatives' preferences, usually palliative care, although we found two discrepant views.

CONCLUSIONS

This study's rare data show ≥95-year-olds are willing to discuss dying and end-of-life care but seldom do. Formal documentation of wishes is extremely rare and may not be welcome. Although being "ready to die" and preferring a palliative approach predominated, these preferences cannot be assumed.

Pain reporting in older adults: the influence of cognitive impairment - results from the Cambridge City >75 Cohort study

OBJECTIVES

Evidence suggests that while disabling back pain (BP), and rheumatic diseases associated with pain, continues to increase with age, the prevalence of non-disabling BP reaches a plateau, or even decreases, in the oldest old. This study aimed to determine whether this age-related pattern of non-disabling BP is a function of increasing cognitive impairment.

METHODS

Cross-sectional study of adults aged >77 years. Participants answered interviewer-administered questions on BP and cognitive function, assessed using the Mini-Mental State Examination, categorised into normal versus mild, moderate or severe impairment. The relationship between cognitive function and BP was examined using multinomial logistic regression, adjusted for age, sex and residence.

RESULTS

Of 1174 participants with BP data, 1126 (96%) completed cognitive assessments. The relationship between cognitive function and BP differed for disabling and non-disabling BP. Across categories of cognitive impairment, increasingly higher prevalence of disabling BP was reported, compared to those with normal cognition, although this was not statistically significant (odds ratio (OR) = 1.7; 95% confidence interval (CI) = 0.7-4.6). No association was found between cognitive function and non-disabling BP (OR = 0.8; 95% CI = 0.4-1.6).

CONCLUSION

This study found no association between the reporting of BP and level of cognitive impairment, suggesting that increasing cognitive impairment is an inadequate explanation for age-related decline in self-reported non-disabling BP. Future research should determine the reasons for the decline in non-disabling pain in older adults, although, meanwhile, it is important to ensure that this group receive appropriate pain assessment and pain management.

KEY POINTS

Prevalence of non-disabling back pain decreases in the oldest old.Some have proposed that this may be a function of cognitive impairment in older age, and an increasing inability to adequately report pain.Our findings do not support this hypothesis.

Re-examining tau-immunoreactive pathology in the population: granulovacuolar degeneration and neurofibrillary tangles

Introduction

Alzheimer’s disease (AD) is associated with neurofibrillary pathology, including neurofibrillary tangles (NFT), neuritic plaques (NP) and neuropil threads containing aggregated microtubule associated protein tau. Aggregated tau is also associated with granulovacuolar degeneration (GVD). The relationships between tau, GVD, NFT and dementia are unclear.

Methods

We assessed hippocampal (CA1) tau-immunoreactive GVD and NFT pathology in brain donations from the population-representative Cambridge City over 75s Cohort (CC75C) using the CERAD protocol and a modified protocol that included a morphological characterisation of tau-immunoreactive deposits within neurons as NFTs or as GVD. Associations between GVD, NFT and dementia were investigated.

Results

Hippocampal pyramidal neurons affected with either NFT or GVD are common in the older population. Some tau-immunoreactive deposits resemble ghost GVD neurons. Tau immunoreactivity identified GVD in 95 % cases rated as none with haematoxylin and eosin staining. Both severe NFT (odds ratio (OR) 7.33, 95 % confidence interval (CI) 2.01; 26.80, p = 0.003) and severe GVD (OR 7.48, 95 %(CI) 1.54; 36.24, p = 0.012) were associated with dementia status. Increasing NFT (OR 2.47 95 %(CI) 1.45; 4.22, p = 0.001) and GVD (OR 2.12 95 %(CI) 1.23; 3.64, p = 0.007) severities are associated with increasing dementia severity. However, when the analyses were controlled for other neuropathologies (NFT, NP, Tar-DNA binding Protein-43 and amyloid deposits), the associations between GVD and dementia lost significance.

Conclusions

Current neuropathological assessments do not adequately evaluate the presence and severity of the GVD pathology and its contribution to dementia remains unclear. We recommend that protocols to assess GVD should be developed for routine use and that tau, in a non-PHF associated conformation, is reliably associated with GVD.

Electronic supplementary material

The online version of this article (doi:10.1186/s13195-015-0141-2) contains supplementary material, which is available to authorized users.

Harnessing the power of cohort studies for dementia research

Purpose

– The purpose of this paper is to scope potential and gaps in European cohort studies with focus on brain ageing and neurodegeneration.

Design/methodology/approach

– Combined and augmented two scoping exercises conducted for European Union Joint Programme on Neurodegenerative Diseases (JPND) and the Alzheimer Society UK.

Findings

– In total, 106 cohorts initially identified with a further 52 found on second sweep. Strengths include gender balance, diversity of measures and much detail on health and health behaviours, and lifecourse representation. Major gaps identified were the oldest old, non-Caucasians, people in Eastern Europe, migrant populations, rural residents and people in long-term care. Quality of life, psychosocial and environmental factors were limited. Relatively few cohorts are population representative. Analytical methods for combining studies and longitudinal analysis require careful consideration.

Research limitations/implications

– European studies and published information only.

Practical implications

– Collaboration across disciplines and studies, greater dissemination of methods and findings will improve knowledge about cognitive and functional decline in current and future older populations.

Social implications

– Better understanding of brain ageing and the dementia syndrome will improve investment decisions for primary, secondary and tertiary prevention.

Originality/value

– Building on the work of JPND and the Alzheimer Society is the first study of the scope and limitations of current cohorts in Europe. It is designed to help researchers and policy makers in their planning.

Cognitive function in a general population of men and women: a cross sectional study in the European Investigation of Cancer-Norfolk cohort (EPIC-Norfolk)

Background

Although ageing is strongly associated with cognitive decline, a wide range of cognitive ability is observed in older populations with varying rates of change across different cognitive domains.

Methods

Cognitive function was measured as part of the third health examination of the European Prospective Investigation of Cancer in Norfolk (EPIC-Norfolk 3) between 2006 and 2011 (including measures from the pilot phase from 2004 to 2006). This was done using a battery consisting of seven previously validated cognitive function tests assessing both global function and specific domains. The battery included a shortened version of the Extended Mental State Exam (SF-EMSE); letter cancellation task; Hopkins Verbal Learning Test (HVLT); Cambridge Neuropsychological Test Automated Battery Paired Associates Learning Test (CANTAB-PAL); Visual Sensitivity Test (VST); Shortened version of the National Adult Reading Test (Short-NART) and a task to test for prospective memory. We report the distribution of cognitive function in different cognitive domains by age and sex and compare the utility of a number of assessment tests in a general population of older men and women.

Results

Cognitive test data were available for 8585 men and women taking part in EPIC-Norfolk 3. Increasing age was generally associated with declining mean cognitive function, but there was a wide range observed within each age group as well as variability across different cognitive domains. Some sex differences were also observed.

Conclusion

Descriptive data are presented for this general population sample of older men and women. There is a wide range of cognitive performance seen in this population. Though average performance declines with age, there is large individual variability across different cognitive domains. These variations may provide insights into the determinants of cognitive function in later life.

Electronic supplementary material

The online version of this article (doi:10.1186/1471-2318-14-142) contains supplementary material, which is available to authorized users.

Place of death and end-of-life transitions experienced by very old people with differing cognitive status: retrospective analysis of a prospective population-based cohort aged 85 and over

BACKGROUND

Despite fast-growing 'older old' populations, 'place of care' trajectories for very old people approaching death with or without dementia are poorly described and understood.

AIM

To explore end-of-life transitions of 'older old' people across the cognitive spectrum.

DESIGN

Population-based prospective cohort (United Kingdom) followed to death.

SETTING/PARTICIPANTS

Mortality records linked to 283 Cambridge City over-75s Cohort participants' cognitive assessments <1 year before dying aged ≥ 85 years.

RESULTS

Overall, 69% were community dwelling in the year before death; of those with severe cognitive impairment 39% were community dwelling. Only 6% subsequently changed their usual address. However, for 55% their usual address on death registration was not their place of death. Dying away from the 'usual address' was associated with cognition, overall fewer moving with increasing cognitive impairment - cognition intact 66%, mildly/moderately impaired 55% and severely impaired 42%, trend p = 0.003. This finding reflects transitions being far more common from the community than from institutions: 73% from the community and 28% from institutions did not die where last interviewed (p < 0.001). However, severely cognitively impaired people living in the community were the most likely group of all to move: 80% (68%-93%). Hospitals were the most common place of death except for the most cognitively impaired, who mostly died in care homes.

CONCLUSION

Most very old community-dwelling individuals, especially the severely cognitively impaired, died away from home. Findings also suggest that long-term care may play a role in avoidance of end-of-life hospital admissions. These results provide important information for planning end-of-life services for older people across the cognitive spectrum, with implications for policies aimed at supporting home deaths. MESH TERMS: Cognitive impairment, Dementia, Aged, 80 and over, Aged, frail elderly, Patient Transfer, Residential characteristics, Homes for the aged, Nursing Homes, Delivery of Health Care, Terminal care Other key phrases: Older old, Oldest old, Place of death, Place of care, End-of-life care.

Health-related quality of life in the Cambridge City over-75s Cohort (CC75C): development of a dementia-specific scale and descriptive analyses

BACKGROUND

The assessment of Health Related Quality of Life (HRQL) is important in people with dementia as it could influence their care and support plan. Many studies on dementia do not specifically set out to measure dementia-specific HRQL but do include related items. The aim of this study is to explore the distribution of HRQL by functional and socio-demographic variables in a population-based setting.

METHODS

Domains of DEMQOL's conceptual framework were mapped in the Cambridge City over 75's Cohort (CC75C) Study. HRQL was estimated in 110 participants aged 80+ years with a confirmed diagnosis of dementia with mild/moderate severity. Acceptability (missing values and normality of the total score), internal consistency (Cronbach's alpha), convergent, discriminant and known group differences validity (Spearman correlations, Wilcoxon Mann-Whitney and Kruskal-Wallis tests) were assessed. The distribution of HRQL by socio-demographic and functional descriptors was explored.

RESULTS

The HRQL score ranged from 0 to 16 and showed an internal consistency Alpha of 0.74. Validity of the instrument was found to be acceptable. Men had higher HRQL than women. Marital status had a greater effect on HRQL for men than it did for women. The HRQL of those with good self-reported health was higher than those with fair/poor self-reported health. HRQL was not associated with dementia severity.

CONCLUSIONS

To our knowledge this is the first study to examine the distribution of dementia-specific HRQL in a population sample of the very old. We have mapped an existing conceptual framework of dementia specific HRQL onto an existing study and demonstrated the feasibility of this approach. Findings in this study suggest that whereas there is big emphasis in dementia severity, characteristics such as gender should be taken into account when assessing and implementing programmes to improve HRQL.

Education associated with a delayed onset of terminal decline

Background: the terminal decline hypothesis suggests an acceleration in the rate of loss of cognitive function before death. Evidence about the association of educational attainment and the onset of terminal decline is scarce.

Objective: to investigate the association of education with the onset of terminal decline in global cognitive function measured by Mini Mental State Exam (MMSE) scores.

Subjects: deceased participants of the Cambridge City over 75 Cohort Study who were interviewed at about 2, 7, 9, 13, 17 and 21 years after baseline.

Methods: regular and Tobit random change point growth models were fitted to MMSE scores to identify the onset of terminal decline and assess the effect of education on this onset.

Results: people who left school at an older age had a delayed onset of terminal decline. Thus better educated individuals experience a slightly shorter period of faster decline before death.

Conclusion: an important finding emerging from our work is that education does appear to delay the onset of terminal decline, although only by a limited amount.

Cognitive and social lifestyle: links with neuropathology and cognition in late life

Many studies report an association of cognitive and social experiential factors and related traits with dementia risk. Further, many clinical-pathologic studies find a poor correspondence between levels of neuropathology and the presence of dementia and level of cognitive impairment. The poor correspondence suggests that other factors contribute to the maintenance or loss of cognitive function, with factors associated with the maintenance of function referred to as neural or cognitive reserve. This has led investigators to examine the associations of cognitive and social experiential factors with neuropathology as a first step in disentangling the complex associations between these experiential risk factors, neuropathology, and cognitive impairment. Despite the consistent associations of a range of cognitive and social lifestyle factors with cognitive decline and dementia risk, the extant clinical-pathologic data find only a single factor from one cohort, linguistic ability, related to AD pathology. Other factors, including education, harm avoidance, and emotional neglect, are associated with cerebrovascular disease. Overall, the associations are weak. Some factors, such as education, social networks, and purpose in life, modify the relation of neuropathology to cognition. Finally, some factors such as cognitive activity appear to bypass known pathologies altogether suggesting a more direct association with biologic indices that promote person-specific differences in reserve and resilience. Future work will first need to replicate findings across more studies to ensure the veracity of the existing data. Second, effort is needed to identify the molecular substrates of neural reserve as potential mediators of the association of lifestyle factors with cognition.

The epidemiology of delirium: challenges and opportunities for population studies

Delirium is a serious and common acute neuropsychiatric syndrome that is associated with short- and long-term adverse health outcomes. However, relatively little delirium research has been conducted in unselected populations. Epidemiologic research in such populations has the potential to resolve several questions of clinical significance in delirium. Part 1 of this article explores the importance of population selection, case-ascertainment, attrition, and confounding. Part 2 examines a specific question in delirium epidemiology: What is the relationship between delirium and trajectories of cognitive decline? This section assesses previous work through two systematic reviews and proposes a design for investigating delirium in the context of longitudinal cohort studies. Such a design requires robust links between community and hospital settings. Practical considerations for case-ascertainment in the hospital, as well as the necessary quality control of these programs, are outlined. We argue that attention to these factors is important if delirium research is to benefit fully from a population perspective.

Are terminal decline and its potential indicators detectable in population studies of the oldest old?

OBJECTIVES

To explore whether it is possible to detect decline in global scores of cognitive function in the proximity of death whilst simultaneously investigating potential risk profiles.

METHODS

Using the Mini Mental State Examination in a population study of the oldest old in which 99% of participants have died, a linear and quadratic time-to-death repeated measures random effects models were used to detect decline and potential factors which might indicate individual variation.

RESULTS

Decline and acceleration of this decline were detectable in the period before death. Some between person variation was detected in this pattern, which included differences in cognitive performance by age at death (-0.2 (SE = 0.02)), sex (-1.2 (SE = 0.2)), initial cognitive impairment (-7.5 (SE = 0.2)) and mobility (-0.6 (SE = 0.2)), in rate of decline by age at death (-0.04 (SE = 0.005)), sex (-0.1 (SE = 0.06)), initial cognitive impairment (-0.3 (SE = 0.07)) and mobility (-0.1 (SE = 0.05)) and differences in change in rate of decline by sex (-0.008 (SE = 0.004)), initial cognitive impairment (-0.02 (SE = 0.04)) and mobility (-0.01 (SE = 0.003)).

CONCLUSION

Using an extension of existing methods for exploring terminal decline, the phenomenon of decline in global cognition measures in the proximity of death was clearly detected as well as potential variables which could influence that pattern. Further work is required to explore whether similar methods can be used to detect the onset of the acceleration of this decline in each individual together with the potential to identify individual level factors that can allow clinicians to distinguish between the normal and preterminal phases of change in extreme old age.

A European perspective on population studies of dementia

The change in the world's age demographics and the predicted rise in the incidence of age-related diseases, including dementia, is a source of major public health concern. Major research effort in both the United States and Europe has been targeted toward understanding the pathogenesis and epidemiology of dementia. This article presents a general overview of the history of dementia research in Europe and how it compares with that in the United States. The review highlights the common issues which both U.S. and European researchers have identified and attempted to tackle. To maximize information gained from studies across the world, better harmonization of methodology is needed, as informed from current research practice.

Engaging the oldest old in research: lessons from the Newcastle 85+ study

BACKGROUND

Those aged 85 and over, the oldest old, are now the fastest growing sector of the population. Information on their health is essential to inform future planning; however, there is a paucity of up-to-date information on the oldest old, who are often excluded from research. The aim of the Newcastle 85+ Study is to investigate the health of a cohort of 85-year-olds from a biological, medical and psychosocial perspective. This paper describes the methods employed for the successful recruitment, retention and evaluation of this cohort.

METHODS

Participants were all individuals born in 1921 and registered with a participating general practice in Newcastle and North Tyneside, UK. Involvement comprised detailed health assessments, by a nurse, in their usual place of residence and/or review of their general practice medical records.

RESULTS

Of the 1453 individuals eligible to participate, 72% (n = 1042) were recruited; 59% (n = 851) consented to both health assessment and review of general practice records. Key factors for successful involvement included protected time to engage with family and other key gatekeepers, minimising participant burden, through for example home based assessment, and flexibility of approach. Cognitive impairment is a significant issue; due consideration should be given to the ethical and legal issues of capacity and consent. Interim withdrawal rates at phase 2 (18 month post baseline), show 88 out of 854 participants (10%) had withdrawn with approval for continued use of data and materials and a further 2 participants (0.2%) had withdrawn and requested that all data be destroyed. Attrition due to death of participants within this same time frame was 135 (16%).

CONCLUSION

Our recruitment rates were good and compared favourably with other similar UK and international longitudinal studies of the oldest old. The challenges of and successful strategies for involving, recruiting and retaining the oldest old in research, including those in institutions, are described to facilitate adequate representation of this growing population in future research into ageing.

Place of death for the 'oldest old': > or =85-year-olds in the CC75C population-based cohort

BACKGROUND

Deaths are rising fastest among the oldest old but data on their transitions in place of care at the end of life are scarce.

AIM

To examine the place of residence or care of > or =85 year-olds less than a year before death, and their place of death, and to map individual changes between the two.

DESIGN OF STUDY

Population-based cohort study.

SETTING

Cambridge City over-75s Cohort (CC75C) study, UK.

METHOD

Retrospective analysis of prospective data from males and females aged > or =85 years at death who died within a year of taking part in any CC75C survey (n = 320); death certificate linkage.

RESULTS

Only 7% changed their address in their last year of life, yet 52% died somewhere other than their usual address at the time of death. Over two-thirds were living in the community when interviewed <1 year before death, but less than one-third who had lived at home died there (less than one-fifth in sheltered housing). Care homes were the usual address of most people dying there (77% in residential homes, 87% in nursing homes) but 15% of deaths in acute hospital came from care homes.

CONCLUSION

More than half the study sample of individuals of advanced old age had a change in their place of residence or care in their last year of life. These findings add weight to calls for improved end-of-life care in all settings, regardless of age, to avoid unnecessary transfers. The study data provide a baseline that can help plan and monitor initiatives to promote choice in location of care at the end of life for the very old.

One size fits all? Why we need more sophisticated analytical methods in the explanation of trajectories of cognition in older age and their potential risk factors

BACKGROUND

Cognitive decline in old age varies among individuals. The identification of groups of individuals with similar patterns of cognitive change over time may improve our ability to see whether the effect of risk factors is consistent across groups.

METHODS

Whilst accounting for the missing data, growth mixture models (GMM) were fitted to data from four interview waves of a population-based longitudinal study of aging, the Cambridge City over 75 Cohort Study (CC75C). At all interviews global cognition was assessed using the Mini-mental State Examination (MMSE).

RESULTS

Three patterns were identified: a slow decline with age from a baseline of cognitive ability (41% of sample), an accelerating decline from a baseline of cognitive impairment (54% of sample) and a steep constant decline also from a baseline of cognitive impairment (5% of sample). Lower cognitive scores in those with less education were seen at baseline for the first two groups. Only in those with good performance and steady decline was the effect of education strong, with an increased rate of decline associated with poor education. Good mobility was associated with higher initial score in the group with accelerating change but not with rate of decline.

CONCLUSION

Using these analytical methods it is possible to detect different patterns of cognitive change with age. In this investigation the effect of education differs with group. To understand the relationship of potential risk factors for cognitive decline, careful attention to dropout and appropriate analytical methods, in addition to long-term detailed studies of the population points, are required.

Education and trajectories of cognitive decline over 9 years in very old people: methods and risk analysis

BACKGROUND

the investigation of cognitive decline in the older population has been hampered by analytical considerations. Most studies of older people over prolonged periods suffer from loss to follow-up, yet this has seldom been investigated fully to date. Such considerations limit our understanding of how basic variables such as education can affect cognitive trajectories.

METHODS

we examined cognitive trajectories in a population-based cohort study in Cambridge, UK, of people aged 75 and over in whom multiple interviews were conducted over time. Cognitive function was assessed using the Mini-Mental State Examination (MMSE). Socio-demographic variables were measured, including educational level and social class. An age-based quadratic latent growth model was fitted to cognitive scores. The effect of socio-demographic variables was examined on all latent variables and the probability of death and dropout.

RESULTS

at baseline, age, education, social class and mobility were associated with cognitive performance. Education and social class were not related to decline or its rate of change. In contrast, poor mobility was associated with lower cognitive performance, increased cognitive decline and increased rate of change of cognitive decline. Gender, age, mobility and cognitive ability predicted death and dropout

CONCLUSIONS

contrary to much of the current literature, education was not related to rate of cognitive decline or change in this rate as measured by MMSE. Higher levels of education do not appear to protect against cognitive decline, though if the MMSE is used in the diagnostic process, individuals with less education may be diagnosed as having dementia somewhat earlier.

Inability to get up after falling, subsequent time on floor, and summoning help: prospective cohort study in people over 90

OBJECTIVES

To describe the incidence and extent of lying on the floor for a long time after being unable to get up from a fall among people aged over 90; to explore their use of call alarm systems in these circumstances.

DESIGN

1 year follow-up of participants in a prospective cohort study of ageing, using fall calendars, phone calls, and visits.

SETTING

Participants' usual place of residence (own homes or care homes), mostly in Cambridge.

PARTICIPANTS

90 women and 20 men aged over 90 (n=110), surviving participants of the Cambridge City over-75s Cohort, a population based sample.

MAIN OUTCOME MEASURES

Inability to get up without help, lying on floor for a long time after falling, associated factors; availability and use of call alarm systems; participants' views on using call alarms to summon help if needed after falling.

RESULTS

In one year's intensive follow-up, 54% (144/265) of fall reports described the participant as being found on the floor and 82% (217/265) of falls occurred when the person was alone. Of the 60% who fell, 80% (53/66) were unable to get up after at least one fall and 30% (20/66) had lain on the floor for an hour or more. Difficulty in getting up was consistently associated with age, reported mobility, and severe cognitive impairment. Cognition was the only characteristic that predicted lying on the floor for a long time. Lying on the floor for a long time was strongly associated with serious injuries, admission to hospital, and subsequent moves into long term care. Call alarms were widely available but were not used in most cases of falls that led to lying on the floor for a long time. Comments from older people and carers showed the complexity of issues around the use of call alarms, including perceptions of irrelevance, concerns about independence, and practical difficulties.

CONCLUSIONS

Lying on the floor for a long time after falling is more common among the "oldest old" than previously thought and is associated with serious consequences. Factors indicating higher risk and comments from participants suggest practical implications. People need training in strategies to get up from the floor. Work is needed on access and activation issues for design of call alarms and information for their effective use. Care providers need better understanding of the perceptions of older people to provide acceptable support services.

Falls in advanced old age: recalled falls and prospective follow-up of over-90-year-olds in the Cambridge City over-75s Cohort study

Background

The "oldest old" are now the fastest growing section of most western populations, yet there are scarcely any data concerning even the common problem of falls amongst the very old. Prospective data collection is encouraged as the most reliable method for researching older people's falls, though in clinical practice guidelines advise taking a history of any recalled falls. This study set out to inform service planning by describing the epidemiology of falls in advanced old age using both retrospectively and prospectively collected falls data.

Methods

Design: Re-survey of over-90-year-olds in a longitudinal cohort study – cross-sectional interview and intensive 12-month follow-up.

Participants and setting: 90 women and 20 men participating in a population-based cohort (aged 91–105 years, in care-homes and community-dwelling) recruited from representative general practices in Cambridge, UK

Measurements: Prospective falls data were collected using fall calendars and telephone follow-up for one year after cross-sectional survey including fall history.

Results

58% were reported to have fallen at least once in the previous year and 60% in the 1-year follow-up. The proportion reported to have fallen more than once was lower using retrospective recall of the past year than prospective reports gathered the following year (34% versus 45%), as were fall rates (1.6 and 2.8 falls/person-year respectively). Repeated falls in the past year were more highly predictive of falls during the following year – IRR 4.7, 95% CI 2.6–8.7 – than just one – IRR 3.6, 95% CI 2.0–6.3, using negative binomial regression. Only 1/5 reportedly did not fall during either the year before or after interview.

Conclusion

Fall rates in this representative sample of over-90-year-olds are even higher than previous reports from octogenarians. Recalled falls last year, particularly repeated falls, strongly predicted falls during follow-up. Similar proportions of people who fell were reported by retrospective and prospective methods covering two consecutive years. Recall methods may underestimate numbers of repeated falls and the extent of recurrent falling. Professionals caring for people of advanced age can easily ask routinely whether someone has fallen at all, or more than once, in the past year to identify those at high risk of subsequent falls.