About TILDA
TILDA: Ireland's Flagship Ageing Study
The Irish Longitudinal Study on Ageing (TILDA) is Ireland’s dedicated national research project, following the lives of over 10,000 adults aged 50 and older across Ireland. It is the largest and most complex undertaking of its kind in Ireland, providing the scientific evidence needed to identify the key factors that influence the ageing process and ultimately improve the quality of life for current and future generations of older adults.
The Ageing Opportunity & Our Mission
Ireland is experiencing an unprecedented demographic shift, with the number of people aged 65 and over projected to increase dramatically. This presents a vital opportunity to create a more inclusive, productive, and healthy society. To prepare for successful population ageing, we urgently require accurate and representative health and socio-economic data.
Our Core Aims are to:
- Determine:
- The health status and health needs of older people.
- The social and economic status and needs of older people.
- The health, economic and social needs of families and carers of older people.
- The biological and environmental components of "successful ageing."
- The contributions that older people are making to society and the economy.
- How Ireland can meet the needs and choices of its citizens in a personalised and positive environment and with due dignity and respect.
- Provide:
- Access to TILDA data following the FAIR Guiding Principles.
- Secure research datasets meeting data protection best practices to keep our participants' personal data safe.
Who Benefits?
- Policy-makers and public sector service planners
- Voluntary sector actors enhancing social integration
- Private sector companies in insurance and services
- Society, young and old, by providing insights for promoting longer, healthier, and more productive lives.
The TILDA Difference: A Longitudinal Approach
Unlike one-off studies that capture a moment in time, TILDA is a longitudinal study. This means we re-interview our participants every two years, observing the changes that occur in their lives over time. This approach provides a rich, dynamic dataset that is unparalleled for understanding the complex process of ageing.
By tracking the same individuals, we can:
- Identify the factors that predict good health and independence in later life.
- Understand the trajectories of physical, mental, and cognitive decline.
- Determine the effectiveness of policy interventions and lifestyle changes.
Our Participants & Data Collection
The Initial Sample Selection
The method used to select participants for the TILDA study was rigorously designed to ensure the sample would be truly nationally representative of the Irish population aged 50 and over.
Recruitment Methodology (Wave 1)
An initial multi-stage sample of addresses was chosen by means of the RANSAM sampling procedure, which was developed by the Economic and Social Research Institute (ESRI). RANSAM is based on the Irish Geodirectory, a comprehensive and up-to-date listing of residential addresses, ensuring each address in the country had an equal probability of selection.
The selected addresses were visited by an interviewer, and all persons aged 50 or over (and their spouses/partners of any age) were canvassed to participate. The final Wave 1 cohort consisted of 8,504 participants, including 8,175 respondents aged 50+ and 329 younger partners. The household response rate to the study was 62%.
Expansion: In 2022, TILDA expanded for the first time to include adults aged 45-64, refreshing the participant group to better understand how modern life shapes ageing across different stages.
Data Collection Methods
Data is collected approximately every two years using three integrated methods:
1. Face-to-Face Interviews (CAPI)
Detailed interviews covering early life experiences, family relationships, emotional/physical health, and financial planning.
2. Self-Completion Questionnaires (SCQ)
Completed privately by the participant for more sensitive topics.
3. Detailed Health Assessment
A comprehensive assessment measuring movement, mobility, muscle strength, heart rate, blood pressure, oral health, memory, and brain blood flow. Participants also generously provide biosamples (blood, stools, hair, and saliva) for biomarker analysis of the ageing process.
All biosamples are processed and stored under strict data protection and quality controls at our state-of-the-art laboratory at St James’s Hospital.
Core Research Domains
TILDA collects comprehensive data across the following interconnected domains:
Physical Health & Function
Cardiovascular health, sensory function, bone density, grip strength, mobility, and health service utilization.
Mental Health & Cognition
Self-rated mood, depression, anxiety, chronic pain, cognitive function, and quality of life measures.
Socio-economic Status
Employment status, pensions, income, assets, education, and housing arrangements.
Lifestyle & Behaviour
Physical activity, nutrition, sleep, alcohol and smoking status, and other personal health behaviours.
Social & Family Context
Social networks, community participation, social support, loneliness, and intergenerational transfers/caring responsibilities.
Research in Action: Policy and Impact
At TILDA, our research highlights that genetic factors only account for 20-30% of the ageing process; lifestyle behaviours and environmental exposures play a pivotal role. The insights generated are immediately translated into real-world applications, shaping national conversations and government policy.
Key Policy Influence Areas
| Policy Area | TILDA's Contribution |
|---|---|
| Healthcare | Findings transformed healthcare strategies, from improving screening for heart arrhythmias and falls, to uncovering untreated conditions like high blood pressure and depression. |
| Public Health | Provided evidence on the critical link between physical activity, diet, and cognitive function, supporting public health strategies like Healthy Ireland. |
| Social Policy | Findings on social isolation and loneliness were instrumental in developing policies aimed at enhancing community engagement and social supports. Also influenced urban planning for age-friendly environments (e.g., accessible pedestrian crossings). |
| Economic Security | Identified challenges related to retirement income and employment beyond age 65, informing public debates on pensions and the future of the labour force. |
Global Leadership: WHO Collaborating Centre
In recognition of our work, the World Health Organization has designated TILDA as its Collaborating Centre for Longitudinal Studies on Ageing and the Life Course. Through this designation, we are helping to develop and refine global ageing studies, supporting the WHO’s goal of establishing similar research in 60% of countries worldwide.
We are deeply grateful to our participants,
whose contribution has created a living record of life, health, and wellbeing in Ireland, helping to shape new policies and advance global education.