Prediction of the Probability and Risk Factors of Early Abdominal Aortic Aneurysm Using the Gradient Boosted Decision Trees Model

Figures & data

Table 1. AAA features

No	Feature	Explain
A1	Age	Age (year)
A2	Sex	1 = male, 0 = female
A3	BP	systolic pressure at rest (mmHg)
A4	TG	Triglycerides (mmol/L)
A5	LDL-C	Low density lipoprotein cholesterol (mmol/L)
A6	Glu	Fasting plasma glucose (mmol/L)
A7	Smoke	Smoking (1 = current smoking and average daily smoking * age >400, 0 = nonsmoking or average daily smoking * age <400)
A8	Drink	Drinking (1 = currently drinking, and average weekly drinking >7 standard drinking units, 0 = no drinking or average weekly drinking <7 standard drinking units)
A9	FH	Family History (1 = medical history of AAA within three generations, 0 = no medical history of AAA within three generations)
A10	BMI	Body mass index = weight (Kg)/ height (cm)^2
A11	Hcy	Homocysteine, u
A12	UA	Uric acid (umol/L)
A13	COPD	Chronic obstructive pulmonary disease.1 = yes, 0 = no
A14	CHD	History of coronary heart disease.1 = yes, 0 = no
A15	CVD	A history of cerebrovascular disease.1 = yes, 0 = no
A16	Target	AAA. 1 = yes, 0 = no

Figure 1. AAA sample set.

Table 2. GBDT parameters

parameter	value
n_trees	50
max_depth	3
n_batches_per_layer	1
center_bias	true

Table 3. The accuracy of NN and GBDT algorithm

Algorithm	Training samples	Test samples	Parameter	Accuracy
NN	320	80	Epoch = 500	89%
GBDT	320	80	Trees = 50	96%

Table 4. Some predicted results of samples (Original and predict target: AAA 1 = yes, 0 = no)

No	Original Target	Probability	Predict Target	Result
0	1	0.47	0	false
1	1	0.89	1	true
2	1	0.95	1	true
3	1	0.93	1	true
4	0	0.13	0	true
5	1	0.93	1	true
6	1	0.89	1	true
7	0	0.25	0	true
8	1	0.93	1	true
9	0	0.06	0	true
…	…	…	…	…

Table 5. Samples of failure predictions (Original and predict target: AAA 1 = yes, 0 = no)

No	Original Target	Probability	Predict Target	Result
0	1	0.47	0	false
33	1	0.47	0	false
74	0	0.66	1	false

Table 6. Weight of each feature

Feature	Weight	Feature	Weight
Age	0.42	FH	0
Sex	0	BMI	0.01
BP	0.17	Hcy	0
TG	0.21	UA	0
LDL-C	0.11	COPD	0
Glu	0.08	CHD	0
Smoke	0	CVD	0
Drink	0

Figure 2. Features in order of weight.

Table 7. DFCs of a healthy person

Feature	Value	Contribution	Feature	Value	Contribution
Age	70	0.1118	FH	0	0
Sex	0	0	BMI	22.7	0
BP	115	0.0248	Hcy	12.9	0
TG	2.78	0.002	UA	381	0
LDL-C	1.65	−0.0696	COPD	0	0
Glu	5.97	−0.0684	CHD	0	0
Smoke	1	0	CVD	0	0
Drink	0	0	Target	0

Figure 3. DFCs of a healthy person.

Table 8. DFCs of an AAA patient

Feature	Value	Contribution	Feature	Value	Contribution
Age	73	0.2579	FH	0	0
Sex	0	0	BMI	22.5	0
BP	147	0.0973	Hcy	14.7	0
TG	4.65	0.0326	UA	362	0
LDL-C	2.89	0.0159	COPD	0	0
Glu	5.9	−0.0204	CHD	0	0
Smoke	0	0	CVD	0	0
Drink	1	0	Target	1

Figure 4. DFCs of an AAA patient.

Figure 5. Age contribution.

Figure 6. BP contribution.

Figure 7. TG contribution.

Figure 8. LDL-C contribution.