The Prospective Epidemiological Risk Factor (PERF) Study is an ambidirectional population-based study of postmenopausal women set up with the purpose of obtaining a better understanding of the aetiology and pathogenesis of age-related diseases. Participants were recruited from a source population of 8875 women residing in Denmark. The baseline examination (PERF I) comprised 5855 women with mean age of 70.8 years (49.7-88.8) and took place between 1999 and 2001. All subjects have been followed up with registry linkage using population-based national registries. Further, a subcohort was re-invited to attend a follow-up visit between 2013 and 2014 (PERF II). Registry data are available for all baseline participants. From the baseline population, 2103 were enrolled in PERF II.

For the Esprit study, 1863 non-institutionalized persons aged 65 years and over were randomly recruited in 1999 from the Montpellier district electoral rolls, and re-examined 6-times at 2-3 yearly intervals. Objectives:

1) To determine current and lifetime prevalence as well as incidence of psychiatric disorder in the elderly;
2) to determine the risk factors for these disorders, their relative weight and interactions;
3) to study clinical heterogeneity;
4) to estimate the probability of transition towards a subsyndromic state or a given pathology;
5) to elaborate predictive etiological models.

The main objective of the FINGER study is to find out if a multi-domain intervention could prevent cognitive decline among older people. With this intervention we also aim to investigate the effect of the multidomain intervention on disability, quality of life, depressive symptoms, the use of health care services and vascular risk factors.

Participants of the FINGER study have previously taken part in population-based non-intervention studies. They have an increased risk of cognitive decline. At the beginning of the study they are 60-77 years old. The FINGER study enrols approximately 1200 participants in six centers in Finland: Helsinki, Kuopio, Oulu, Seinäjoki, Turku and Vantaa.

The Maastricht Aging Study (MAAS) was designed to specify the usual and pathological aging of cognitive function. MAAS is devoted to the age-related decline of memory and other cognitive functions in normal people and the factors that may be involved in this process. What determines a decline in memory function? Why do some individuals show a greater decline than others? Over the past years, a host of factors, including biological, medical, psychological and social variables, have been proposed to have an impact on adult cognitive development. MAAS tries to study these factors in an integrative way. This can be achieved only by studying large numbers of normal healthy adults of all ages and by monitoring them for several years.

The health of the agricultural population has been previously explored, particularly in relation to the farming exposures and among professionally active individuals. However, few studies specifically focused on health and aging among elders retired from agriculture. Yet, this population faces the long-term effects of occupational exposures and multiple difficulties related to living and aging in rural area (limited access to shops, services, and practitioners). However, these difficulties may be counter-balanced by advantages related to healthier lifestyle, richer social support and better living environment. The general aim of the AMI cohort was to study health and aging in elderly farmers living in rural area through a multidisciplinary approach, with a main focus on dementia.

The study started in 2007, with two follow-up visits over 5 years. Baseline visits were conducted at home by a neuropsychologist then by a geriatrician for all cases suspected of dementia, for all subjects suspected of being demented. The 10-year visit is currently on going.

The aim of the Cambridge Centre for Ageing and Neuroscience (Cam-CAN) project is to identify the neural mechanisms underpinning successful cognitive ageing. The study recruitment participants over 18 from resident within Cambridge City and used epidemiological, behavioural, and neuroimaging data to understand how individuals can best retain cognitive abilities into old age. A major aim of the research programme is to understand the nature of brain-cognition relationships across the lifespan, and to highlight the importance of abilities that are maintained into old age.

This population study was not designed to have repeated measures for each participant, but rather as one extended and comprehensive study visit that took place over 3 stages.

This is a feasibility study which has a Longitudinal Cohort design, following up participants at selected time points over a 1 year duration. The study will recruit 2 distinct groups: (1) patients with symptoms of cognitive impairment, and (2) study partners who are cognitively normal. The patients recruited to group 1 will have been recently referred to a Memory Assessment Service by their GP with suspected Mild Cognitive Impairment (MCI) & mild dementia. All patients referred to a Memory Assessment Service for this reason will be potentially eligible for inclusion in the study. Close friends or family members involved in looking after the cognitively impaired participants will also be asked to participate as study partners to attempt to measure the impact that looking after a partner, friend or family member with memory problems can have on a carer’s Quality of Life and other variables such as financial burden. Both cognitively impaired participants and their study partners will be given the option of additionally participating in two sub-studies:

– Mobile data collection: Using a web/mobile app to collect self-reported data on a more regular basis from home

– Wearable device: Using a wearable device that looks like a watch to collect information on activity and sleep

The Vallecas Project is developed in the Research Unit of the Alzheimer’s Center of the Reina Sofía Foundation by researchers of the CIEN Foundation. Its main objective is to determine a probabilistic algorithm for the identification of individuals at risk of dementia type Alzheimer’s disease (AD) in the course of a few years. This algorithm will be based on the combination of sociodemographic, clinical, neurological, neuropsychological, biological (from blood determinations) and neuroimaging (various 3 Tesla magnetic resonance modalities).

The recruitment phase of the Vallecas Project participants was extended from October 2011 to December 2013. Finally, a total of 1,213 volunteers aged between 70 and 85 and of both sexes were initially evaluated. Once included in the study, it is monitored annually for 5 years in order to assess the evolutionary profile of all participants, specifically identifying those who develop cognitive impairment and / or dementia. The cohort is being followed up annually for 4 years after the baseline.

This project comprises of two complementary parts. One part is aimed at the development of innovative diagnostic techniques to detect molecular signatures of AD based on disturbances of amyloid metabolism and glutamate neurotransmission. In this part, the focus is on the two most promising diagnostic approaches in AD: (molecular) imaging techniques and molecular diagnostic tests of CSF. In the second part of this study, techniques for which proof-of-concept has been found in humans are applied in a large group of AD patients. These patients are recruited in an established network of 4 collaborating memory clinics in The Netherlands, which use a standardized diagnostic protocol and share an extensive common database. Furthermore, more mature molecular, structural, and functional imaging and molecular diagnostic CSF techniques as well as the conventional diagnostic work-up will be applied from the start of the study in patients from the same network of memory clinics.

LEILA75+ is a prospective population-based cohort study on the epidemiology of dementia and other neurodegenerative disorders. The main aims of the study included to determine a) the prevalence and incidence of dementia as well as subtypes of dementia, b) the prevalence and incidence of mild cognitive impairment (MCI) and c) the occurrence of other related conditions, such as subjective cognitive decline (SCD). Likewise, it was aimed at identifying risk factors and groups of high-risk-individuals for the development of dementia, MCI and SCD.

Overall, 1,692 individuals of at least 75 years of age (from private households as well as from institutions) were approached via random selection from the registry office of the city of Leipzig (response rate: 81%). Finally, the LEILA75+ cohort consisted of 1,265 individuals at baseline. Data collection took place at participants homes through structured interviews (incl. socio-demographic variables, a cognitive test battery/SIDAM, functional and psychosocial assessments, medical conditions). If participants’ were not able to complete assessments, proxy information was gathers from relatives. After baseline assessment in 1997/1998, 5 follow-up waves were conducted every 1.5 years. Additionally, a long-term follow-up was performed 15 years after baseline.

Further study details have been published in:
Riedel-Heller SG, Busse A, Aurich C, Matschinger H, Angermeyer MC. Prevalence of dementia according to DSM-III-R and ICD-10: results of the Leipzig Longitudinal Study of the Aged (LEILA75+) Part 1. British Journal of Psychiatry 2001; 179: 250-254.

Riedel-Heller SG, Busse A, Aurich C, Matschinger H, Angermeyer MC. Incidence of dementia according to DSM-III-R and ICD-10: results of the Leipzig Longitudinal Study of the Aged (LEILA75+), Part 2. British Journal of Psychiatry 2001; 179: 255-260.

Riedel-Heller S, G, Schork A, Matschinger H, Angermeyer M, C, Recruitment Procedures and Their Impact on the Prevalence of Dementia. Neuroepidemiology 2000;19:130-140.