MRC CFAS began in the late 1980s with the initial aim of investigating dementia and cognitive decline in a representative sample of more than 18,000 people aged over 65 years. The study primarily aimed to find out how common dementia and associated conditions are in England and Wales and also, how many new cases of dementia develop each year. The range of information collected in the interviews has also allowed the study to also investigate depression and physical disability in the older population in addition to looking at healthy active life expectancy. MRC CFAS ran from 1989 – 2011. Having provided estimations of dementia occurrence for the UK, CFAS was increasingly asked to provide evidence on generational change in dementia, cognition and life expectancy by the government and the public, leading to its daughter studies, CFAS II & CFAS Wales.