A Population-based study of dementia in the oldest old: the Monzino 80-plus study

[Neuropsychological differences in Alzheimer's disease depending on the age of onset]

INTRODUCTION

Early-onset Alzheimer's disease (EOAD) has been defined as a dementia due to AD presenting before the arbitrarily established age of 65 (as opposed to late-onset Alzheimer's disease or LOAD). There is still little research about other age sub-groups, the use of so-called senile dementia has been banished, usually including it within the late-onset Alzheimer's dementia. To the extent of our knowledge, there are no studies comparing the neuropsychological features of very-late-onset patients with early and late-onset ones.

METHODS

We retrospectively selected 359 patients with a diagnosis of probable AD dementia. We subdivided patients into three groups attending to the age of onset of the disease: early-onset AD (EOAD; younger than 65 years old), late-onset AD (LOAD; between 65 and 80) and very-late-onset AD (VLOAD; defined here as onset age older than 80), and then we compared their neuropsychological results.

RESULTS

AD patients with a younger age at onset scored worse on attention, executive function and visuospatial skills, while older-onset patients scored worse in memory tasks and language. Patients with a very-late-onset differed from the late-onset ones in a greater impairment of semantic fluency and naming.

CONCLUSION

Although the point of separation between EOAD and later-onset forms of EA at the age of 65 is an arbitrary one, our study shows that there are significant differences between these groups from a neuropsychological point of view. However, these differences do seem to follow a linear trend with age, rather than representing fundamentally distinct clinical pictures.

MoCA 7.1: Multicenter Validation of the First Italian Version of Montreal Cognitive Assessment

Background:

The early detection of neurocognitive disorders, especially when mild, is a key issue of health care systems including the Italian Dementia National Plan. The Mini-Mental State Examination (MMSE), i.e., the reference screening tool for dementia in Italian Memory Clinics, has low sensitivity in detecting mild cognitive impairment (MCI) or mild dementia.

Objective:

Availability of a 10-minute screening test sensitive to MCI and mild dementia, such as the Montreal Cognitive Assessment (MoCA), is relevant in the field. This study presents initial validity and reliability data for the Italian version of MoCA 7.1 that is being collected as part of a large ongoing longitudinal study to evaluate the rate of incident MCI and dementia in older adults.

Methods:

MoCA 7.1 and MMSE were administered to cognitive impaired patients (n = 469; 214 with MCI, 255 with dementia; mean age: 75.5; 52% females,) and healthy older adults (n = 123, mean age: 69.7, 64 % females).

Results:

Test-retest (0.945, p < 0.001) and inter-rater (0.999, p < 0.001) reliability of MoCA 7.1, assessed on randomly selected participants with normal cognition, MCI, dementia, were significant. MoCA 7.1 showed adequate sensitivity (95.3%) and specificity (84.5%) in detecting MCI compared to MMSE (sensitivity: 53.8%; specificity: 87.5%). The Area Under the Curve of MoCA 7.1 was significantly greater than that of MMSE (0.963 versus 0.742). MoCA 7.1 showed similar results in detecting both MCI and dementia.

Conclusion:

MoCA 7.1 is a reliable and useful tool that can aid in the diagnosis of MCI and dementia in the Italian population.

Mild anemia and 11- to 15-year mortality risk in young-old and old-old: Results from two population-based cohort studies

Background

Mild anemia is a frequent although often overlooked finding in old age. Nevertheless, in recent years anemia has been linked to several adverse outcomes in the elderly population. Objective of the study was to investigate the association of mild anemia (hemoglobin concentrations: 10.0–11.9/12.9 g/dL in women/men) with all-cause mortality over 11–15 years and the effect of change in anemia status on mortality in young-old (65–84 years) and old-old (80+ years).

Methods

The Health and Anemia and Monzino 80-plus are two door-to-door, prospective population-based studies that included residents aged 65-plus years in Biella municipality and 80-plus years in Varese province, Italy. No exclusion criteria were used.

Results

Among 4,494 young-old and 1,842 old-old, mortality risk over 15/11 years was significantly higher in individuals with mild anemia compared with those without (young-old: fully-adjusted HR: 1.35, 95%CI, 1.15–1.58; old-old: fully-adjusted HR: 1.28, 95%CI, 1.14–1.44). Results were similar in the disease-free subpopulation (age, sex, education, smoking history, and alcohol consumption adjusted HR: 1.54, 95%CI, 1.02–2.34). Both age groups showed a dose-response relationship between anemia severity and mortality (P for trend <0.0001). Mortality risk was significantly associated with chronic disease and chronic kidney disease mild anemia in both age groups, and with vitamin B₁₂/folate deficiency and unexplained mild anemia in young-old. In participants with two hemoglobin determinations, seven-year mortality risk was significantly higher in incident and persistent anemic cases compared to constant non-anemic individuals in both age groups. In participants without anemia at baseline also hemoglobin decline was significantly associated with an increased mortality risk over seven years in both young-old and old-old. Limited to the Monzino 80-plus study, the association remained significant also when the risk was further adjusted also for time-varying covariates and time-varying anemia status over time.

Conclusions

Findings from these two large prospective population-based studies consistently suggest an independent, long-term impact of mild anemia on survival at older ages.

The Expected Demand for Elderly Care Services and Anticipated Living Arrangements Among the Oldest Old in China Based on the Andersen Model

Objective: The first aim of this study was to explore expected demands of the oldest old and their determinants for different types of elderly care services. The second aim was to investigate preferred choices of living arrangements among the oldest old and the influencing factors.

Methods: Data of 4,738 participants aged ≥80 years were extracted from the Chinese Longitudinal Health Longevity Survey carried out in 2014. Using the Andersen model as the analysis framework, a multiple logistic regression analysis was performed to analyze the relationship between the expected elderly care services and living arrangements and other influencing factors. The odds ratios were calculated to indicate the relationship between the influencing factors and the dependent variables.

Results: From the descriptive analysis results, we found that the oldest old showed high anticipated needs for home visits (83.5%) and health education (76.4%). Further, there existed a huge imbalance between the supply and demand of care services for the aged. Living with children is still the most important way of providing for the oldest old. The regression results showed that the expected demands for elderly care services and anticipated living arrangements among the oldest old in China are influenced by age, residence, housing property rights, economic status, loneliness, and activities of daily living (ADLs). The oldest old who are older without housing property rights, childless, and have restricted ADLs were more frequently observed to live in long-term care institutions.

Conclusions: There is an inequality of the supply and expected demand for elderly care services, and living with children is still a preferred choice of the Chinese oldest old. Our findings indicate that when planning how to promote elderly care services among the oldest old, it is important to consider their expectations, especially for the subgroup that is relatively disadvantaged. Related policies should be developed to offer incentives to family caregivers when they live with the oldest old.

The role of diet on the risk of dementia in the oldest old: The Monzino 80-plus population-based study

BACKGROUND & AIMS

Longevity also carries its dark side of age-related chronic diseases, dementia being one of the worst and the most prevalent. Since dementia lacks effective treatments, preventing or delaying it is highly desirable. Dietary habits and nutrition have been found to be important modifiable risk factors for many chronic diseases, but evidence on the role of diet on the risk of dementia is still limited, particularly among the very old. Aim of the present work is to study the association of the Mediterranean diet and its components with prevalent and incident dementia in the oldest-old.

METHODS

We analyzed data from the Monzino 80-plus study, a population-based study in subjects 80 years or older in the Varese province, Italy. A validated food frequency questionnaire was used to collect information on 23 different foods consumed in the previous year. A Mediterranean diet score was calculated and its components were classified into tertiles. Multivariable models for dementia prevalence and incidence were adjusted for demographic and clinical characteristics.

RESULTS

Information on nutrition was available for 1390 subjects in the cross-sectional study and 512 subjects in the longitudinal study, mean respective ages 93 and 92. Greater adherence to Mediterranean diet, greater consumption of eggs, fruits and vegetables, carbohydrates, and greater food intake were associated with a lower prevalence of dementia. Increasing number of portions per week and consumption of legumes significantly decreased the incidence of dementia during the 3.6 year mean follow-up: corresponding hazard ratios of highest vs. lowest tertiles (95% confidence intervals) were 0.66 (0.46-0.95) and 0.68 (0.47-0.97), respectively.

CONCLUSION

Oldest-old eating less and having diets with less variety and nutrient density were more frequent among subjects with dementia. The longitudinal analysis confirmed oldest-old subjects who eat more portions, as well as those who have a higher intake of legumes, are at decreased risk of developing dementia even though reverse causality cannot be completely ruled out.

Physical and mental health in the oldest-old: a mixed-methods study on a southern Italy sample

BACKGROUND

The world's aging population has been constantly increasing in the last decades, causing the number oldest-old individuals to increase.

AIMS

The present study aims to explore the different variables that contribute to the oldest-old wellbeing using a mixed-methods approach, including self-reports, standardized measures, and semi-structured interviews.

METHODS

Thirty-nine oldest-old (90-103) from southern Italy were involved in the study, together with a control sample of younger individuals (51-71) from the same families.

RESULTS

Data suggest that the oldest-old have better mental health, higher resilience, and more optimism than younger individuals. High resilience seems to be the key variable that promotes the overall wellbeing.

DISCUSSION

The oldest-old tend to have better mental health, higher resilience and more optimism than younger individuals.

CONCLUSIONS

Wellbeing in the oldest-old appeared to be promoted by the sense of belonging and life purpose.

Physical activity is associated with lower cerebral beta-amyloid and cognitive function benefits from lifetime experience-a study in exceptional aging

BACKGROUND

Exceptional agers (85+ years) are characterized by preserved cognition presumably due to high cognitive reserve. In the current study, we examined whether personality, risk and protective factors for dementia as well as quality of life are associated with core features of Alzheimer's disease (amyloid-deposition and hippocampal volume) as well as cognition in exceptional aging.

METHODS

We studied 49 exceptional agers (average 87.8 years, range 84-94 years), with preserved activities of daily living and absence of dementia. All participants received a detailed clinical and neuropsychological examination. We used established questionnaires to measure lifetime experience, personality, recent physical and cognitive activity as well as quality of life. Cerebral amyloid-deposition was estimated by 18-[F]-Flutemetamol-PET and manual hippocampal volumetry was performed on 3D T1 MRI images.

RESULTS

In this sample of exceptional agers with preserved activities of daily living, we found intact cognitive performance in the subjects with the highest amyloid-load in the brain, but a lower quality of life with respect to autonomy as well as higher neuroticism. Higher self-reported physical activity in the last twelve months went with a lower amyloid load. Higher self-reported leisure-time/ not work-related activity went with better executive functioning at older age.

CONCLUSION

Even in exceptional aging, high amyloid load may subtly influence personality and quality of life. Our findings support a close relationship between high physical activity and low amyloid-deposition and underscore the importance of extracurricular activities for executive functions. As executive functions are known to be a central resource for everyday functioning in fostering extracurricular activities may be effective in delaying the onset of dementia.

Cognitive, functional, physical, and nutritional status of the oldest old encountered in primary care: a systematic review

Background

The oldest old (individuals over 90 years) are a fast-growing population. Characterizing their specificity would be helpful to adapt health care. This study aimed to characterize the cognitive, functional, nutritional, and physical status of individuals over 90.

Methods

We conducted a systematic review of cross-sectional or cohort studies of individuals aged 90 years old or more, living at home or in a nursing home, in April 2018. Two reviewers selected eligible articles, extracted data, and evaluated the risk of bias (assessed by the Newcastle-Ottawa Scale).

Results

The search strategy identified 3086 references; 35 articles were included referring to 8 cross-sectional and 27 longitudinal studies. Dementia was diagnosed in 30–42.9% of study participants, cognitive impairment in 12–50%, and 31–65% had no cognitive impairment. In terms of activities of daily living, 14–72.6% of individuals had no difficulty, 35.6–38% had difficulty, and 14.4–55.5% were dependent. For instrumental activities of daily living, 20–67.9% needed help. Regarding nutritional status, the Mini Nutritional Assessment Short Form mean score ranged from 10.3 (SD: 1.8) to 11.1 (SD: 2.4). Eight to 32% of individuals could not stand up from a chair, 19–47% could stand without the use of their arms; and 12.9–15% were not able to walk 4 m.

Conclusions

These results suggest a heterogeneous population with a certain proportion of oldest old with a low level of disability. These findings suggest that a specific approach in the care of the oldest old could help prevent disability.

Incidence of dementia in the oldest-old and its relationship with age: The Monzino 80-plus population-based study

INTRODUCTION

Relationship between age and dementia at extreme old ages is still an open question, yet population-based studies in this high-risk age segment are rare.

METHODS

The Monzino 80-plus is a population-based study among residents 80 years and older in the Varese province, Italy. Of 1371 eligible individuals, 1294 (94.4%), of whom 64 are centenarians, were included in the incidence study.

RESULTS

Since 2002, 584 new cases of all-cause dementia were identified over 15 years. The overall incidence rate was 7.9 per 100 person-years. Dementia risk rose with age (IRR: 1.06), with the cubic model providing the best fit (R²  = 0.91-0.96). Cumulative incidences of dementia unadjusted and adjusted for competing mortality risk progressively diverged with age.

CONCLUSION

Dementia incidence also keeps rising in nonagenarians and centenarians. Slowing down in growing risk of developing dementia with age is mainly attributable to increasing competing risk of death and resulting selective survival of individuals at lower risk of dementia.

Cohort profile: 'Centenari a Trieste' (CaT), a study of the health status of centenarians in a small defined area of Italy

PURPOSE

Centenarians, a segment of the population which some 50 years ago comprised only a few individuals, now count thousands in many countries, and demographic projections forecast that this growth will continue. The study of this new population will give us new information on extreme longevity and help prepare for their health and social needs. The aim of the Centenari a Trieste study is to describe the health and health service use by centenarians, with specific focus on cognitive status.

PARTICIPANTS

This is a population-based study of centenarians living in the province of Trieste (Italy), a small area with a high prevalence of centenarians and a close network of health and social services, which makes it possible to conduct a study. Consenting individuals were visited by a clinician, tested by neuropsychologists and also gave a sample of their blood. Administrative data were retrieved as well.

FINDINGS TO DATE

Of the 163 centenarians, 70 could be contacted and participated in the study. The main reasons for non-participation were impossibility to contact the subject (70) and death (20). Centenarians were mostly women (90%), tended to live in a nursing home (60%) and were generally severely functionally impaired (Barthel Index <50: 61%). Data from the administrative database showed that about one out of five needed hospitalisation in the preceding year and more than three out of four had at least one drug prescription.

FUTURE PLANS

In 2017, we started a new wave of the study enrolling people who had just become centenarian and reassessing subjects already seen; we hope to extend this recruitment in the next years. Subjects are now examined also by cardiologists and dental specialists. We are collecting further different biological specimens to investigate new hypotheses on the cognitive function of the centenarians.

A Systematic Review and Meta-Analysis on the Prevalence of Dementia in Europe: Estimates from the Highest-Quality Studies Adopting the DSM IV Diagnostic Criteria

BACKGROUND

Dementia, including Alzheimer's disease (AD), is one of the most burdensome medical conditions. Usually, the reviews that aim at calculating the prevalence of dementia include estimates from studies without assessing their methodological quality. Alzheimer's Disease International (ADI) proposed a score to assess the methodological quality of population-based studies aimed at estimating the prevalence of dementia. During the last three years, the European Commission has funded three projects (Eurodem, EuroCoDe, and ALCOVE) in order to estimate the prevalence of dementia in Europe.

OBJECTIVE

The aim of this study was to perform a systematic review and meta-analysis of data on the prevalence of dementia in Europe derived from studies that included only subjects with a diagnosis of dementia according to the DSM IV criteria, and that had a high quality score according to ADI criteria.

METHODS

We considered the studies selected by the two projects EuroCoDe (1993-2007) and Alcove (2008-2011), and we performed a new bibliographic search. For the systematic review, we only selected the subset of articles that included subjects with a diagnosis of dementia according to the DSM IV criteria. The studies were qualitatively assessed using the ADI tool.

RESULTS

The meta-analysis considered 9 studies that were carried out in Europe between 1993 and 2018 including a total of 18,263 participants, of which 2,137 were diagnosed with dementia. The prevalence rate standardized for age and sex resulted 7.1%.

DISCUSSION

This is the first systematic review on the prevalence of dementia in Europe considering only high-quality studies adopting the same diagnostic criteria (i.e., DSM IV).

The impact of methods to handle missing data on the estimated prevalence of dementia and mild cognitive impairment in a cross-sectional study including non-responders

OBJECTIVE

Although several statistical methods for adjusting for missing data have been developed and are widely applied in research, few studies have investigated these methods in adjusting for missingness in datasets that aim to estimate the prevalence of dementia. We attempted to develop a more feasible approach for handling missingness in a cross-sectional study among elderly.

METHODS

Five methods of estimating prevalence, including stratified weighting (SW), inverse-probability weighting (IPW), hot deck imputation (HDI), ordinal logistic regression (OLR) and multiple imputation (MI), were applied to handle the missing data yielded by a dataset that include 2231 non-responders.

RESULTS

Compared with the results of the complete case analysis, the differences in the prevalence rates of dementia and mild cognitive impairment (MCI) calculated by the prevalence-estimating methods after adjusting for non-responders were less than 7% and 6%, respectively. In contrast to the results of other methods, the estimated prevalence of dementia and MCI calculated by MI increased when more predictive factors were included, and the lowest rate of missing data was achieved using MI. Using the participants' ages, the cognitive screening sores and activity of daily life sores as predictive variables when correcting for missingness induced relatively larger effects on the estimated dementia prevalence.

CONCLUSIONS

When adjusting for missingness while estimating the prevalence of dementia in cross-sectional studies, a simple method, such as SW, is recommended when limited information is available, whereas MI is the preferred method when additional information is available. Further simulation studies are needed to determine the optimal approach.

A systematic review of the quality of studies on dementia prevalence in Italy

Background

Dementia, including Alzheimer’s disease (AD), is one of the most burdensome medical conditions. In order to better understand the epidemiology of dementia in Italy, we conducted a systematic search of studies published between 1980 and April 2014 investigating the prevalence of dementia and AD in Italy and then evaluated the quality of the selected studies.

Methods

A systematic search was performed using PubMed/Medline and Embase to identify Italian population-based studies on the prevalence of dementia among people aged ≥60 years. The quality of the studies was scored according to Alzheimer’s Disease International (ADI) criteria.

Results

Sixteen articles on the prevalence of dementia and AD in Italy were eligible and 75 % of them were published before the year 2000. Only one study was a national survey, whereas most of the studies were locally based (Northern Italy and Tuscany). Overall, the 16 studies were attributed a mean ADI quality score of 7.6 (median 7.75).

Conclusions

Available studies on the prevalence of dementia and AD in Italy are generally old, of weak quality, and do not include all regions of Italy. The important limitations of the few eligible studies included in our analysis, mostly related to their heterogeneous design, make our systematic review difficult to interpret from an epidemiologic point of view. Full implementation of a Dementia National Plan is highly needed to better understand the epidemiology of the disease and monitor dementia patients.

A systematic review of the quality of studies on dementia prevalence in Italy

BACKGROUND

Dementia, including Alzheimer's disease (AD), is one of the most burdensome medical conditions. In order to better understand the epidemiology of dementia in Italy, we conducted a systematic search of studies published between 1980 and April 2014 investigating the prevalence of dementia and AD in Italy and then evaluated the quality of the selected studies.

METHODS

A systematic search was performed using PubMed/Medline and Embase to identify Italian population-based studies on the prevalence of dementia among people aged ≥60 years. The quality of the studies was scored according to Alzheimer's Disease International (ADI) criteria.

RESULTS

Sixteen articles on the prevalence of dementia and AD in Italy were eligible and 75 % of them were published before the year 2000. Only one study was a national survey, whereas most of the studies were locally based (Northern Italy and Tuscany). Overall, the 16 studies were attributed a mean ADI quality score of 7.6 (median 7.75).

CONCLUSIONS

Available studies on the prevalence of dementia and AD in Italy are generally old, of weak quality, and do not include all regions of Italy. The important limitations of the few eligible studies included in our analysis, mostly related to their heterogeneous design, make our systematic review difficult to interpret from an epidemiologic point of view. Full implementation of a Dementia National Plan is highly needed to better understand the epidemiology of the disease and monitor dementia patients.

Normative Data for the Cognitively Intact Oldest-Old: The Framingham Heart Study

BACKGROUND/STUDY CONTEXT: The number of individuals who reach extreme age is quickly increasing. Much of the current literature focuses on impaired cognition in extreme age, and debate continues regarding what constitutes "normal" cognition in extreme age. This study aimed to provide oldest-old normative data and to compare cognitive performances of cognitively intact elderly individuals from the Framingham Heart Study.

METHODS

A total of 1302 individuals aged 65+ years from the Framingham Heart Study were separated into 5-year age bands and compared on cognitive tests. Multivariate linear regression analyses were conducted, adjusting for gender, the Wide Range Achievement Test-Third Edition (WRAT-III) Reading score, and cohort. Analyses also included comparisons between 418 individuals aged 80+ and 884 individuals aged 65-79, and comparisons within oldest-old age bands.

RESULTS

Normative data for all participants are presented. Significant differences were found on most tests between age groups in the overall analysis between young-old and oldest-old, and analysis of oldest-old age bands also revealed select significant differences (all ps <.05).

CONCLUSION

As aging increases, significant cognitive differences and increased variability in performances are evident. These results support the use of age-appropriate normative data for oldest-old individuals.

Characteristics of participants' and caregivers' influence on non-response in a cross-sectional study of dementia in an older population

OBJECTIVE

The issue of non-response in dementia epidemiological studies, which may result in the underestimation of the prevalence of dementia, has attracted little attention. We aimed to explore the causes and related factors of non-response in a dementia survey among Chinese veterans.

METHODS

A two-phase, cross-sectional study investigated the prevalence of dementia and mild cognitive impairment in Chinese veterans aged ≥ 60 years. We collected the socio-demographic data and prior medical history, evaluated the health status of veterans and their caregivers, assessed the cognitive status of veterans, and evaluated the care burden of caregivers by Caregiver Burden Inventory (CBI).

RESULTS

Of 9676 eligible participants, 525 (5.4%) veterans in phase 1 and 1706 (35.0%) veterans among 4875 veterans in phase 2 did not respond. Illness, hospitalization and death accounted for 63.0% and 75.5% non-response in phases 1 and 2, respectively. Non-participation in social activities, self-perceived poor health status, worsened health changes, self-reported need for life care, and history of hearing loss or glaucoma independently predicted non-response in phase 1 or 2. The heavy care burden, suggested by the higher CBI scores and self-reported health deterioration of the primary caregivers, predicted non-response in phase 1 or 2.

CONCLUSIONS

The negative factors from both the participants and their caregivers independently predicted the non-response in the dementia study in an older population. Preventative strategies from the perspectives of the participants and caregivers should be developed to improve the response rates in both phases in a cross-sectional study.

Pflegebedürftigkeit und Multimorbidität

Menschen, die derzeit in Pflegeheimen betreut werden, sind in der Regel hochbetagt und fortgeschritten multimorbid. Die Mehrzahl von ihnen ist an Demenz erkrankt. Daher haben sich die Hauptaufgaben der Pflegeheime in den vergangenen 25 Jahren grundlegend verändert. Gute Lebensqualität für die Betroffenen kann nur durch fachgerechte Pflegeleistungen, professionelle geriatrische und palliativmedizinische Behandlung, sowie Kompetenz aller Mitarbeiter in Kommunikation mit Menschen mit Demenz gewährleistet werden.

Midlife Hypertension Risk and Cognition in the Non-Demented Oldest Old: Framingham Heart Study

Midlife cardiovascular risk, hypertension (HTN) in particular, has been related cross-sectionally to poorer neuropsychological (NP) performance in middle age and older adults. This study investigated whether a similar relationship persists between midlife HTN or systolic blood pressure (SBP) and NP performance approximately 30 years later. 378 Framingham stroke and dementia-free Original cohort participants, with HTN and SBP ascertained between 50-60 years of age (mean age 55 ± 1, 65% women), were administered a NP assessment at age ≥80 years. Tests included Logical Memory, Visual Reproduction, Paired Associate, Hooper Visual Organization Test, Trail Making A & B, Digit Span Forward and Backward, Controlled Word Association Test (COWAT), and Similarities. Multivariable linear regression, adjusted for age, time interval between risk factor and NP testing, gender, and premorbid intelligence, assessed association between midlife HTN/SBP and NP outcomes. Midlife HTN was not significantly associated with NP outcome measures. Midlife SBP was associated with poorer Digit Span Forward and COWAT performance (p <  0.05). No significant interaction of age on HTN/SBP to NP associations was found. There was a significant interaction between ApoE4 status and SBP in their effects on COWAT (pinteraction = 0.074); SBP was negatively associated with COWAT only in those with the ApoE4 allele (p = 0.025). While midlife HTN is not associated with late life cognitive impairment, midlife SBP is related to late life attention and verbal fluency impairments, particularly among ApoE4+ individuals. These results offer insight into processes that are operative in the absence of overt cognitive impairment and dementia.

European studies on the prevalence of dementia in the elderly: time for a step towards a methodological consensus

OBJECTIVE

The aim of this study was to discuss methodological limitations in studies on the prevalence of dementia across European countries with particular attention to post-EURODEM studies.

METHODS

Two people independently focused on an iterative literature search for studies published in the years 2000-2012 using the following keywords: 'dementia', 'Alzheimer', 'incidence', 'prevalence' that were cross-linked with names of European countries. After that, the results obtained were compared and publications in English were included in a subsequent analysis.

RESULTS

We included 26 studies published in the years 2000-2012. The majority of epidemiological studies come from Spain and Italy. The past decade has not provided prevalence rates from a considerable number of countries. There is also a lack of nationwide surveys on the prevalence of dementia. Predominantly, epidemiological studies on the prevalence of dementia follow a two-stage approach that consists of a screening phase and a subsequent confirmation of dementia. However, several differences, particularly with regard to the neuropsychological instruments used, still exist and contribute to inconsistent prevalence rates.

CONCLUSIONS

Although the EURODEM study was a milestone in the epidemiology of dementia in Europe and provided several future directions for research, methodological limitations are apparent in a number of European studies on the prevalence of dementia and require particular attention. In particular, a variety of diagnostic instruments requires unification for future studies. On the other hand, given the lack of epidemiological studies from a number of countries and the increasing prevalence of dementia, the need for population-based surveys should be emphasized.