The Irish Longitudinal Study on Ageing (TILDA)
The Irish Longitudinal Study on Ageing (TILDA) is a longitudinal study of a nationally representative sample of older 8,000 older people aged 50 years and over living in the community in Ireland. The overarching aim of TILDA is to improve the understanding of how health, economic and social circumstances contribute to (successful) ageing and to make Ireland the best place in the world to grow old.
TILDA collects information on health, economic and social circumstances from people aged 50 and over in a series of data collection waves once every two years. Over 8,500 people took part in the first wave of TILDA in 2009 and 2010. Participants were asked questions about a range of topics including health, housing, social support, work, retirement, pensions and quality of life and this was followed up with a health assessment. The results are published in a report called ‘Fifty Plus in Ireland 2011: First Results from The Irish Longitudinal Study on Ageing’ (Barrett et al., 2011).
Wave 2 of the study, which commenced in early 2012, is now complete. Wave 2 involved re-visiting and re-interviewing participants from the first wave. In addition to the topics covered in Wave 1, some new questions were added, including on personality. There was no separate health assessment during this wave, but the interviewers took a measure of handgrip strength and walking speed when they visited participants in their homes. The first results from Wave 2 have now been published in a report titled 'The Over 50s in a Changing Ireland: Economic Circumstances, Health and Well-Being' (Nolan et al., 2014).
Wave 3 of the study was completed in 2015. Participants were interviewed in their own home with 80% also completing a health assessment. Both the interview and health assessment included cognitive testing. The health assessment also included measures of sensory function, and cardiovascular health. Questions on cardiovascular disease and behavioural health (smoking, physical activity and sleep) cholesterol screening, employment, and social connectedness have much relevance for the potentially modifiable risks factors associated with dementia. There is evidence that occupational level, educational level, and social engagement can enhance brain function and protect against or at least delay the onset of dementia.
The first results from Wave 3 were published in a report entitled ‘Health and Wellbeing: Active Ageing for Older Adults in Ireland. Evidence from the Irish Longitudinal Study on Ageing’.
Wave 4 took place during 2016 with over 6000 interviews carried out in participants own homes. New questions in this wave were related to health literacy and childhood health. No health assessment was carried out in this wave but a measure of handgrip strength and walking speed were taken.
Wave 5 is scheduled to take place in 2018. This will again involve a personal interview in the participant's home and a self-completion questionnaire. There will be no health assessment but measures of hand grip strength and walking speed will be taken.
A comprehensive list of TILDA reports, academic papers and study documents can be found on the TILDA website, several of which address cognitive function/impairment and which have relevance of policy and practice on dementia, but none address dementia specifically.