Transcript A MINUTE ALZHEIMER SCREEN

Screening for
Alzheimer’s Disease
General Principles
J.W. Ashford,
University of Kentucky
Veterans Affairs Medical Center
Lexington
AAGP – 3/3/03
Early Recognition of AD: Consensus
Statement
(AAGP, AGS, Alzheimer’s Association)
AD continues to be missed as diagnosis
AD is unrecognized and under-reported
patients do not realized
 families tend to compensate

Effective treatment and management
techniques are available
Small et al., JAMA, 1997
Why Diagnose AD
Early?
Safety (driving, compliance, cooking, etc.)
Family stress and misunderstanding (blame, denial)
Early education of caregivers of how to handle
patient (choices, getting started)
Advance planning while patient is competent (will,
proxy, power of attorney, advance directives)
Patient’s and Family’s right to know
Specific treatments now available


May slow underlying disease process
May delay nursing home placement longer if started
earlier
Importance of screening
for Alzheimer’s disease
Early treatments may:



Slow the course of the disease
Delay nursing home placement
Decrease the cost of the disease
Very early treatments may prevent dementia
What is the cost of testing versus the cost of
not testing?
At what age is testing cost-effective?
U.S. Census 2000 by age
Males,
138,053,563
Females,
143,368,343
2,500,000
2,250,000
# people
2,000,000
1,750,000
1,500,000
1,250,000
Total = 281,421,906
>60 = 45,809,291
>65 = 35,003,844
>85 = 4,251,678
>100=
62,545
1,000,000
750,000
500,000
250,000
0
0
10
20
30
40
50
Age
60
70
80
90 100
U.S. mortality by age - 1999
Males, 1,175,460
45,000
Number of people
40,000
Females, 1,215,939
35,000
30,000
25,000
20,000
15,000
10,000
5,000
0
0
10
20
30
40
50
Age
60
70
80
90
100
U.S. mortality rate by age
1999 CDC / 2000 census
Males
Females
dementia incidence
probability
1.0000
0.1000
0.0100
0.0010
0.0001
0
10 20
30 40 50 60 70
Age
80 90 100
U.S. mortality rate by age
1999 CDC / 2000 census
probability
1.0000
0.1000
0.0100
y = 9 E- 0 5 e
0.0010
R 2 = 0.9974
y = 3 E- 0 5 e 0 . 0 9 2 6 x
0. 0848x
R 2 = 0.9973
0.0001
30
Males,
40
50
60
Td = 8.2 yrs
Females, Td = 7.5 yrs
70
80
Age
90
100
# / yr
U.S. Dementia Incidence
(4 million / 8yr)
male=170,603
16000
14000
12000
10000
8000
6000
4000
2000
0
female=329,115
50
60
70
80
Age
90
100
Proportional risk / yr
Dementia incidence by individual
male=34%
0.016
0.014
0.012
0.01
0.008
0.006
0.004
0.002
0
female=66%
50
60
70
80
Age
90
100
Age Specific Dementia Rate
Probability / yr
1
0.1
0.01
0.001
0.0001
50
60
70
80
Age (years)
90
100
Factors Influencing
Variation in Age of Onset
Genetics (especially APOE), family history
Neurological factors


Stroke
Brain injury
Medical factors


Vascular disease
Medications: NSAIDS, statins, female HRT
Education
Gender
Ageism (more concern for younger individuals)
Age-Associated Memory Impairment
(loss of memory without loss of social function)
vs
Mild Cognitive Impairment / Early Alzheimer
Memory declines with age

At what point is memory abnormal?

Heisenbergian uncertainty –


How does age affect consideration of abnormality?


the earlier problem is, the less clearly defined it is.
Memory problems are more tolerated in older individuals
Older individuals remember more complex items and
relationships
Older individuals are slower to respond
ALZHEIMER’S DISEASE
Estimate MMSE as a function of time
MMSE score
30
25
20
15
10
5
0
-10
-8
-6
-4
-2
0
2
4
6
Estimated years into illness
Ashford et al., 1995
AAMI / MCI
DEMENTIA
8
10
100%
90%
80%
60%
AD
MCI
Non-Affected
50%
40%
30%
20%
10%
Age
84
82
80
78
76
74
72
70
68
66
64
62
0%
60
Percentage
70%
Yesavage et al., 2002
BLT/Ashford Memory Test
(to detect AD onset)
New test to screen patients for
Alzheimer’s disease using the WorldWide Web – based testing
Test only takes 1-minute
Test can be repeated often (quarterly)
Any change over time can be detected
Test is at: www.ibaglobal.com/BLT
For info, see: www.medafile.com