Health and wealth does not affect incidence of dementia in England and Wales
23 August 2005
Results from the Medical Research Council (MRC) Cognitive Function and Ageing Study show that improved health and mortality are not likely to guard against the risk of developing dementia, according to a paper published today in Public Library of Science Medicine by Dr Fiona Matthews of the MRC Biostatistics Unit in Cambridge and Professor Carol Brayne from the University of Cambridge.
The Medical Research Council Cognitive Function and Ageing study (MRC CFAS) interviewed 13,004 individuals aged 65 years and above using identical methodology from five diverse locations across England and Wales. The multi-centre study measures robustly, for the first time, any variation of the incidence of dementia across five sites within England and Wales and produces overall estimates by age and sex. It concludes that there is no convincing evidence of variation in dementia rates across England and Wales.
Dementia is a change in mental function sufficiently severe to interfere with day-to-day living and affects around 550,000 people in the UK. The incidence of dementia is known to vary between nations, but clear variation has not been shown in western countries. This is the first study of its kind within a single country.
Incidence rates for dementia rise with age both in men and women. In individuals aged 75-79 years, 1 in 70 people will develop dementia in any given year. In those aged 85 years and above, where the population is set to increase the most over the next decade, this increases to 1 in 15. The study estimates that approximately 163,000 new cases of dementia occur in England and Wales each year.
Dr Matthews, Senior Research Scientist at the MRC Biostatistics Unit said, "One quarter of people aged 85 and over suffer from dementia. This new research will help those planning services for people with dementia to estimate requirements now and in the future. However, more research is needed to find out if the incidence of dementia in the UK is rising or falling"
Professor Brayne, Professor of Public Health Medicine at the Department of Public Health and Primary Care, University of Cambridge, said, "Unlike with many chronic diseases, the rates of new development of dementia across England and Wales do not seem to be influenced by factors such as health and overall mortality. This could be because the moderate lifestyle differences and variation in mortality across England and Wales are not sufficiently great to influence the incidence of dementia, whereas in many parts of the world the differences in incidence of dementia between countries are sufficiently large to be easily detectable."
For more information or to arrange an interview with Dr Matthews or Professor Brayne, contact the MRC Press Office: 020 7637 6011/pressoffice@headoffice.mrc.ac.uk
Notes for Editors
1. The Medical Research Council (MRC) is a national organisation funded by the UK tax-payer. Its business is medical research aimed at improving human health; everyone stands to benefit from the outputs. The research it supports and the scientists it trains meet the needs of the health services, the pharmaceutical and other health-related industries and the academic world. MRC has funded work that has led to some of the most significant discoveries and achievements in medicine in the UK. About half of the MRC's expenditure of approximately £500 million is invested in its 40 Institutes, Units and Centres. The remaining half goes in the form of grant support and training awards to individuals and teams in universities and medical schools.
2. The MRC Cognitive Function and Ageing Study is a collaborative study set up by the MRC and the Department of Health in the early 1990's. Researchers from across England and Wales have been involved since it began. The core analysis is currently based at the Department of Public Health and Primary Care, University of Cambridge and the MRC Biostatistics Unit also in Cambridge. Lead principal investigators involved in the fieldwork since the study began are Prof. Tom Arie (Nottingham), Prof. John Bond (Newcastle), Prof. Carol Brayne (Chair 2000 onwards, Cambridge), Prof. John Copeland (Gwynedd), Prof. Nick Day (Chair 1989-2000, Cambridge), Dr Devakumar (Gwynedd), Dr Mike Dewey (Nottingham), Dr. Andrew Fairbairn (Newcastle), Prof. John Grimley-Evans (Oxford), Dr F Huppert (Cambridge), Prof. David Kay (Newcastle), Mrs. Cherie McCracken (Gwynedd), Prof. Ian McKeith (Newcastle), Prof. Kevin Morgan (Nottingham), Prof. Gene Paykel (Cambridge).
3. The University of Cambridge's reputation for outstanding academic achievement is known worldwide and reflects the intellectual achievement of its students, as well as the world-class original research carried out by the staff of the University and the Colleges. As Cambridge approaches its 800th anniversary in 2009, it is looking to the future. It continues to change in response to the challenges it faces. The modern University is an international centre of teaching and research in a vast range of subjects: about half of the students study science or technology. Members of the University have won over 80 Nobel Prizes. The University website is http://www.cam.ac.uk.
4. The MRC Biostatistics Unit, located in Cambridge, was founded over 40 years ago. Its aims are to advance the cause, natural history and treatment of disease, and to evaluate public health strategies, through the development of statistical methods and their application to the design, analysis and interpretation to biomedical studies.
5. The five locations included in this study are: rural Cambridgeshire (Ely and surrounding villages); Gwynedd and Ynos Mon (Anglesey); Nottingham; Newcastle upon Tyne and Oxford.
