COGNITIVE FUNCTION AND DEMENTIA IN 6 AREAS OF ENGLAND AND WALES - THEDISTRIBUTION OF MMSE AND PREVALENCE OF GMS ORGANICITY LEVEL IN THE MRC CFA STUDY

Background. This two-stage prevalence survey involved geographically d elimited areas, four urban (Liverpool, Newcastle, Nottingham and Oxfor d) and two rural (Cambridgeshire and Gwynedd), including institutions. Methods. Stratified random population samples of people in their 65th year and above, from Family Health Service Authorities were studied. The sample was stratified (65-74 years and greater than or equal to 75 ) to provide equal numbers. In Liverpool equal numbers in 5 year age g roups were taken. After an initial screening interview, approximately 20% were selected on the basis of age, AGECAT organicity confidence le vel and MMSE score to proceed to a detailed assessment interview from which the full AGECAT organicity confidence level could be derived. Re sults. Major influences on MMSE were confirmed as age, sex, social cla ss and educational level. Estimates of prevalence of AGECAT O3 and abo ve for each centre and the entire sample according to age are given, b ased on 1991 Census population structure, and suggest that around half a million (543 400) people in England and Wales would be defined as c ase level by this method. The five centres employing the same methodol ogy showed no heterogeneity in prevalence. Conclusions. Prevalence of cognitive impairment and dementia appear not to vary widely across the centres examined in this study, which provides stable estimates by ag e and sex for AGECAT O3 and above, and norms for MMSE. Using these est imates as an indication of the size of the population affected, around 550 000 individuals in England and Wales would be expected to be suff ering from dementia of mild or greater severity.