Prevalence of Dementia in England and Wales

Prevalence – the number of cases of a disease that are present in a particular population at a given time.

MRC CFAS used identical methods in five sites, two in rural areas and three in cities (Cambridgeshire, Nottingham, Gwynedd, Newcastle and Oxford). Each of these sites has different prevalence of risk factors and mortality rates. 

The initial population sample was drawn from registers of general practitioners (Family Health Service Authorities lists) and random selection was carried out to recruit at least 2,500 individuals in each centre. The prevalent cases were identified in two stages. The entire study sample underwent a screening interview to pick up potential cases, and those potential cases then had a more detailed assessment. Table 1 below shows the results of this prevalence study.

  

Table 1      Prevalence of dementia by age and sex (%) (pooled results from five centres of the Medical Research Council Cognitive Function and Ageing Study)

Age-group

Men (%)

Women (%)

65-69

1.4

1.5

70-74

3.1

2.2

75-79

5.6

7.1

80-84

10.2

14.1

85+

19.6

27.5

 

The prevalence of cognitive impairment and dementia did not show much variation across the centres examined in the study, so the combined prevalence data is generalisable for the national population.

Standardised to the England and Wales population estimates for 1991 the overall prevalence of dementia and above in the 65 years and over population was 6.6% (95% CI 5.9-7.3).

Table 2       Prevalence of dementia - Overall estimates standardized to the population of England and Wales aged over 65 years

 

 

Men

5.6

Women

7.0

Total population

6.6 (5.9-7.3)

 

These estimates suggest that around half a million (543,000) people in England and Wales would be expected to be suffering from dementia of mild or greater severity.

Reference
MRC CFAS (1998) Cognitive function and dementia in six areas of England and Wales: the distribution of MMSE and prevalence of GMS organicity level in the MRC CFA Study. Psychological Medicine, 28: 319-335

Health and Society

CFA Studies

Aims of the CFA Studies
Design of the CFA Studies
Biological Samples

Summary of Findings

Prevalence of Dementia
Prevalence of Dementia in Institutional Care
Incidence of Dementia
Risk Factors for Dementia
Disability and Healthy Ageing
Costs of Dementia
Healthy Active Life Expectancy
Neuropathology

Supplementary Information From Publications

Operationalisation of Mild Cognitive Impairment