CFAS -Incidence of Dementia

Incidence of Dementia

Incidence measures the number of new events or cases of disease that develop in a population of individuals at risk during a specified time interval.

CFAS published estimates of the incidence of Dementia in England and Wales in 2005.

The study 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.

Table 1 presents the incidence rates for dementia found by the CFAS study. The results show that the increase in incidence with age is marked for both sexes, and continues into the oldest age groups with no tailing off.

Dementia - Incidence
rate by age
Powerpoint slide

Table 1 Incidence Rate per 1,000 Person Years with 95% Confidence Intervals (all centres combined)

Age group	Men	Women	Men & Women
65-69	6.9 (3.3-14.5)	6.3 (2.9-15.6)	6.7 (3.8-12.4)
70-74	14.5 (7.4-34.1)	6.1 (2.8-12.6)	10.3 (6.2-19.9)
75-79	14.2 (6.7-25.1)	14.8 (8.5-25.1)	14.5 (9.6-20.7)
80-84	17.0 (6.7-34.1)	31.2 (21.2-34.1)	26.5 (18.3-37.7)
85+	58.4 (27.3-96.7)	71.7 (52.0-96.7)	68.5 (52.5-88.1)

There was no convincing evidence of variation across the different centres and the incidence rates did not reflect the variations in the prevalence of possible risk factors in these sites.

From the CFAS results it can be estimated that approximately 163,000 new cases of dementia occur in England and Wales each year. (95% CI 96,000 to 272,000)

Matthews F, Brayne C, Investigators MRC CFAS (2005) The Incidence of Dementia in England and Wales: Findings from the Five Identical Sites of the MRC CFA Study. PLoS
Med 2(8): e193
http://medicine.plosjournals.org/perlserv/?request=get-document&doi=10.1371/
journal.pmed.0020193

Correction – Some of the data in the abstract and the results were incorrect
(2005) Correction: The incidence of dementia in England and Wales: Findings from the five identical sites of the MRC CFA study. PLoS Med 2 (10):e389
http://medicine.plosjournals.org/perlserv?request=get-document&doi=10.1371/
journal.pmed.0020389

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