The MRC Multicentre Study of Cognitive Function and Ageing: a EURODEM incidence study in progress.

The purpose of this paper is to describe the design and methodology of this multicentre study of cognitive function and ageing, which is currently funded by the Medical Research Council (MRC) and the Department of Health for a period of 5 years. The study is designed to estimate and compare the prevalence and incidence of dementia in five centres in the United Kingdom, to examine the natural history of cognitive decline and dementia in the population and to evaluate the degree of disability associated with any decline. This will be achieved by the examination, twice, of the cognitive function of individuals aged 65 and over, with an interval of 2 years between the examinations. A 20% subsample, taken across the full range of cognitive function will be reviewed annually in more detail to chart the level of cognitive function and to ascertain a diagnosis of dementia. This represents the first systematic examination of different populations using a common methodology in the United Kingdom.