The ZARADEMP project (ZARAgoza DEMentia
DEPression project) was designed as a longitudinal,
community-based study to examine the incidence
of dementia and the risk factors in incident cases of
dementia. It was carried out in Zaragoza, a typical,
large city in Spain, with an important proportion
of inhabitants coming from surrounding rural
areas (12). A stratified random sample of individuals
55 years of age and older, with proportional
allocation by age and sex, drawn from the eligible
individuals (n = 157 787) in the Spanish official
census lists of 1991, was invited to participate in
the baseline examination.

The Atherosclerosis Risk in Communities Study (ARIC) is a prospective epidemiologic study conducted in four U.S. communities. ARIC is designed to investigate the etiology and natural history of atherosclerosis, the etiology of clinical atherosclerotic diseases, and variation in cardiovascular risk factors, medical care and disease by race, gender, location, and date. Since 2011 a large ancillary study, the ARIC Neurocognitive Study (ARIC-NCS) has been assessing neurocognitive status and adjudicating possible cases of dementia.

Four ARIC field centers each randomly selected and recruited a cohort sample of approximately 4,000 individuals aged 45-64 from a defined population in their community. A total of 15,792 participants received an extensive baseline examination (visit 1, 1987-1989), including medical, social, and demographic data collection. Subsequent examinations occurred in 1990-92 (visit 2), 1993-95 (visit 3), 1996-98 (visit 4), 2011-2013 (visit 5) and 2016-2017 (visit 6). Visit 7 (2018-2019) is currently in progress. Follow-up occurs annually (semi-annually since 2012) by telephone to maintain contact with participants and to assess health status of the cohort.

The Confucius Hometown Aging Project (CHAP) is a longitudinal study of vascular risk factors, ageing, and health in people aged 60 years or older who live in a rural community near Qufu (hometown of Confucius), Shandong, China. The study was done by local hospital staff consisting of clinicians and nurses.

JSTAR project researchers aimed to construct a world-class longitudinal dataset on middle-aged and elderly Japanese persons to enable researchers worldwide to perform scientific investigation on aging and retirement from an international perspective. Despite the rapid aging of the Japanese population, no statistical survey that could properly capture the diversity of the elderly population from various viewpoints had been carried out in Japan until recently. RIETI, Hitotsubashi University jointly launched a comprehensive survey of elderly people in 2007 to collect panel data on their lives and health, with the University of Tokyo joining from 2009 onward.
The 2009 JSTAR survey includes a follow-up survey of the respondents to the 2007 survey and an initial survey of elderly people in two additional municipalities, i.e., Tosu in Saga Prefecture and Naha in Okinawa Prefecture, whereas the 2011 JSTAR Survey includes follow-up surveys of the respondents to the 2007 and 2009 surveys plus an initial survey of elderly people in three additional municipalities, Tondabayashi, Chofu, and Hiroshima

LifeGene is a national collaborative project designed to build up a resource for research in all medical disciplines, enabling new and groundbreaking research on the relationships among heredity, environment and lifestyle. The study includes studying several hundred thousand Swedes with the aim of creating new tools to prevent, diagnose and treat our most common diseases. LifeGene constitutes a platform for a myriad of biomedical research projects. Researchers not only in biomedicine and biotechnology but also behavioral and social sciences may benefit from access to LifeGene. By combining a biological perspective with e-epidemiology, LifeGene opens up new possibilities for a greater understanding of the interplay between heredity, lifestyle and the environment as regards to our most common diseases.

The 1970 British Cohort Study (BCS70) follows the lives of more than 17,000 people born in England, Scotland and Wales in a single week of 1970. Over the course of cohort members lives, the BCS70 has collected information on health, physical, educational and social development, and economic circumstances among other factors.

The National Child Development Study (NCDS) is a longitudinal study which follows the lives of 17,000 people born in England, Scotland and Wales in a single week of 1958. Also known as the 1958 Birth Cohort Study, it collects information on physical and educational development, economic circumstances, employment, family life, health behaviour, wellbeing, social participation and attitudes.

Since the birth survey in 1958, there have been nine further ‘sweeps’ of all cohort members at ages 7, 11, 16, 23, 33, 42, 46, 50 and 55. In 2003 (at age 45), 9,000 cohort members also participated in a special bio-medical survey to learn more about how development, environments and lifestyles affect people’s health. CLS will carry out a new survey of the NCDS cohort at age 60 in 2018.

NCDS is part of CLOSER (Cohort & Longitudinal Studies Enhancement Resources) which aims to maximise the use, value and impact of the UK’s longitudinal studies.

The MyHeART study is longitudinal cohort study of 1361 schoolchildren (13-years old) attending 15 public secondary schools from the central (Kuala Lumpur and Selangor) and northern (Perak) regions of Peninsular Malaysia. The study used a stratified sampling design to select the study participants. Data collected at baseline included socio-economic, lifestyle (e.g. smoking, physical activity assessment, fitness assessment, seven-day diet history), and environmental information, anthropometric measurements, blood pressure, handgrip strength and bone mineral density. Blood samples for fasting blood glucose and lipid profiles, full blood count, renal profile, as well as bone profile and serum vitamin D were taken. This study cohort will be followed up again when participants turn 15, 17 and lastly, after a period of ten years (around the age of 27).

Recruitment Period: 2004
Sample size at start or planned sample size if still recruiting: 16,122 (15,770 households included at Sweep 1; 352 ethnic boost interviews added at Sweep 4)
Estimated current sample size: 15,629
Age at recruitment: 13-14

Next Steps (previously known as the Longitudinal Study of Young People in England – LSYPE) is a major innovative cohort study of young people. The study began in 2004 and included all young people in Year 9, aged between 13 and 14, who attended state and independent schools in England.

Next Steps is one of the main information sources for the formation and appraisal of policies relating to young people and will continue to be so for at least the next 10 years. The baseline data will be used to monitor the progress of the cohort group, evaluate the success of policies aimed at this group and provide an evidence base for further policy development. The study brings together data from a wide range of sources and reflects the variety of influences on learning and progression.

Following the initial survey at age 13-14, the cohort members were visited every year until 2010, when they were age 19-20. Young people were interviewed along with their parents up to sweep 4 (age 17).

The most recent survey took place in 2015/16, when the cohort members were 25 years old. It maintained the strong focus on education, but the content was broadened to become a more multi-disciplinary research resource. Data was collected about cohort members’ housing and family life, employment and economic circumstances, education and job training, physical and emotional health, and identity and participation. A wide range of administrative data linkage consents were collected in the domains of health, education, economics and criminal behaviour.

The Nurses’ Health Study II (NHS II) was established by Dr. Walter Willett and colleagues in 1989 with funding from the National Institutes of Health to study oral contraceptives, diet, and lifestyle risk factors in a population younger than the original NHS cohort.

Why a new cohort of nurses?
This younger generation of nurses included women who started using oral contraceptives during adolescence and were thus maximally exposed during their early reproductive life. Several case-control studies suggesting such exposures might be associated with substantial increases in breast cancer risk provided a particularly strong justification for investment in this large cohort. Researchers also planned to collect detailed information on the types of oral contraceptives used, which was not obtained in the Nurses’ Health Study.

In addition, NHS II obtained information on physical activity and diet in adolescence and early adult life.