1. Epidemiology of Dementias
Gerald van Belle
Biostatistics and ADRC
University of Washington

2. Outline Definition of dementia, AD Prevalence and incidence
Risk factors (including protective)
Assessing disease progression
Why is AD research so hard?
Summary

3. Definitions Dementia: original meaning madness Current meaning:
“…global, non-reversible impairment of cerebral function with preservation of clear consciousness. It usually results in loss of memory…executive function…changes in personality.” (BMJ/CE).

4. Definitions Alzheimer’s disease
“…insidious onset...slow deterioration…may be diagnosed after other systemic and neurological causes of dementia have been excluded clinically and by laboratory investigation.” (BMJ/CE).

5. Prevalence of AD South Carolina Study (Laditka et al, 2004)
Rate per 1000
Age
Men
Women
Eur. Am
Afr. Am

6. Prevalence of Dementia— Jorm Model
Rate per 1000 person years
Age Model

7. Incidence of Dementia Kukull et al (2002) Rate per 1000 person years
Age Dementia AD

8. Incidence of Dementia— Jorm-like Model
Rate per 1000 person years
Age Model

9. “Risk” Factors for AD Genetic/familial Environmental Cultural Medical
Other categories?
Subject of lots of research

10. Assessing Disease Progression
Activity of daily living
Cognitive assessment
Clinical/caregiver setting (ADL is key)
Research setting (Cognitive enters)
Clinical trials
Disease modeling
Risk factor assessment

11. Why is AD Research so Hard?
Diagnosis by exclusion
Gold standard (neuropath) is tarnished
Treatments are palliative
Cognitive tests are biased
Slow disease progression
Inability of subject to contribute detailed information
Competing risks

12. Summary
Prevalence of dementia doubles every five years. Rate at age 65 about 1 per 100
Approximately 70% of dementia is AD
Very few disease-specific risk factors
Disease progression research focuses on cognition
AD has unique aspects