De prevalentie bij ouderen van de ziekte van Alzheimer, vasculaire dementie en dementie bij de ziekte van Parkinson; het ERGO-onderzoek

To assess the prevalence of dementia and its subtypes in the general population aged 55 years and over.

Design

Population based, cross-sectional study.

Setting

Ommoord, a suburb of Rotterdam, the Netherlands.

Methods

From July 1989 until July 1993, 7528 participants of the Rotterdam study, aged 55 to 106 years, were screened for dementia using the ‘Mini-mental state examination’ and the ‘Geriatric mental state schedule, community version’. Screenpositive persons were further examined extensively for dementia. In persons with a dementia syndrome the subdiagnosis was established.

Results

The prevalence of dementia was 6.3, ranging fro 0.4 in those aged 55-59 years to 43.2 in those aged 95 years and older. From the age of 60 to 85 years the prevalence doubled with every five years increase of age. Alzheimer's disease was the major subtype (72) followed by vascular dementia (16) and dementia associated with Parkinson's disease (6).

Conclusion

The prevalence of dementia increased exponentially with age. Over one-third of those aged 85 years and older suffered from a dementia syndrome. About three-quarters of all dementia cases were classified as Alzheimer's disease. Based on these prevalence figures it is estimated that 160,000 of the Dutch aged 55 years and older suffer from dementia.