Variable Interactions in Risk Factors for Dementia
Jim O’ Donoghue, Mark Roantree and Andrew McCarren
Research funded by:European Union Seventh Framework Programme, grant agreement number 304979and Science Foundation Ireland, grant agreement number SFI/12/RC/2289.
Dementia
1 Alzheimer Europe, The prevalence of Dementia in Europe, Online: http://www.alzheimer-europe.org/Policy-in-Practice2/Country-comparisons/The-prevalence-of-dementia-in-Europe; Last Accessed 30-05-16 .
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Dementia
2 Alzheimer Society, Dementia 2014 Report: Opportunity for Change; Online: https://www.alzheimers.org.uk/dementia2014; Last Accessed 30-05-16.
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Dementia
2 Alzheimer Society, Dementia 2014 Report: Opportunity for Change; Online: https://www.alzheimers.org.uk/dementia2014; Last Accessed 30-05-16.
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Test dementia factors
:7 combinations testedImprove survival predictions
:Neural networksDetermine factor interactions
:Hidden layer analysis
Process2. Parameter optimisation
1. initialise architecture
2. construct hypothesis
3. build cost
4.
5.29
Process2. Parameter optimisation
1. initialise architecture
2. construct hypothesis
3. build cost
4. construct model
5.30
Process2. Parameter optimisation
1. initialise architecture
2. construct hypothesis
3. build cost
4. construct model
5. train31
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a(1)0
InputVisible Layer
h(1)
……𝑥2
a(1)o…a(1)
2a(1)1
Hidden
𝑥1 𝑥𝑛𝑥0
Layer
𝑥
OutputVisible Layer 𝑜
W(1)
38
a(1)0
InputVisible Layer
W(1)
h(1)
……𝑥2
a(1)o…a(1)
2a(1)1
W(2)
Hidden
𝑥1 𝑥𝑛𝑥0
Layer
𝑥
D1
OutputVisible Layer
CD2S 𝑜
Classifications
S -> Surivival
D1 -> Dementia
D2 -> Death (without dementia)
C -> Censorship (study drop-out)
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a(1)0
InputVisible Layer
W(1)
h(1)
……𝑥2
a(1)o…a(1)
2a(1)1
W(2)
Hidden
𝑥1 𝑥𝑛𝑥0
Layer
𝑥
D1
OutputVisible Layer
CD2S 𝑜
40
a(1)0
InputVisible Layer
W(1)
h(1)
……𝑥2
a(1)o…a(1)
2a(1)1
W(2)
Hidden
𝑥1 𝑥𝑛𝑥0
Layer
𝑥
D1
OutputVisible Layer
CD2S 𝑜
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VariablesMaastricht Ageing Study (MAAS)
840x25 subset
-> 15 binary
-> 9 continuous/discrete
-> 1 derived
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Combinations14 factors
-> 11 modifiable
3 protective
- Cognitive ativity
- Physical activity
- Moderate alcohol use46
Combinations14 factors
-> 11 modifiable
8 risk- Smoking
- Mid-life obesity
- Mid-life hypertension
- Diabetes
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- Cholesterol- Cardiovascular
disease- Kidney disease - Depression
Combinations14 risk factors
-> 11 modifiable
-> 3 non-modifiable
7 combinations tested
-> 3 baseline no relative risk weight
-> 4 with relative risk48
Combinationswithout relative risk weights
B1 = BinaryBaseline1
B2 = BinaryBaseline2
CB = ContinuousBaseline
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Combinationswithout relative risk weights
B1 + B2:
11 binary modifiable;
adjusting for age, sex + education
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Combinationswithout relative risk weights
B1 + B2:
11 binary modifiable;
adjusting for age, sex + education
dementia yes/no vs. multi-class
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Combinationswithout relative risk weights
B1 + B2:
binary modifiable; adjusting;
dementia yes/no vs. multi-class
CB:
6 binary; ;
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Combinationswithout relative risk weights
B1 + B2:
binary modifiable; adjusting;
dementia yes/no vs. multi-class
CB: 6 binary; ;
modifiable; adjusting; multi-class53
Combinations
BW1: 11 binary mod. adjusted
BW2: 11 mod. adj.
BW3: 11 mod.
CW: 6 binary; 5 continuous
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batch size (1, 50)
n hidden nodes (2, 20)
learning rate (0.0001, 0.3)
regularisation (0.0001, 0.1)
max epochs (100, 2000)
max iterations (5000, 100000)
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batch size (1, 50)
n hidden nodes (2, 20)
learning rate (0.0001, 0.3)
regularisation (0.0001, 0.1)
max epochs (100, 2000)
max iterations (5000, 100000)
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0.0187
0.0002
0.0221
0.003
0.0001 0.0002
B2-sd CB-sd BW1 BW2-sd BW3 CW-sd
Predictive Significance
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Risk Interactions
-0.39178
-0.004
-0.003
-0.002
-0.001
0
0.001
0.002
0.003
0.004
h1 h2 h3 h4 h5 h6
age_risk educ_risk cog_actphys_inact obese diabetesdi_alcohol smokes depressedhyperT cholesterol cvdkidney
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Risk Interactions
-0.39178
-0.004
-0.003
-0.002
-0.001
0
0.001
0.002
0.003
0.004
h1 h2 h3 h4 h5 h6
age_risk educ_risk cog_actphys_inact obese diabetesdi_alcohol smokes depressedhyperT cholesterol cvdkidney
Neural network framework
Confirm and improve predictionsCandidate risk interactions
Continuous Data + Relative Risk Weight Importance
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Research funded by:European Union Seventh Framework Programme, grant agreement number 304979and Science Foundation Ireland, grant agreement number SFI/12/RC/2289.
Middle-aged individuals (40 – 60)
Risk Profiler +
Support Environment
Dementia Risk Factors
In-Mindd
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