Influence of Lifestyles on Mild Cognitive Impairment: A Decision Tree Model Study

Figures & data

Table 1 MCI Studies Variable Assignment

Research Variables	Assignment Situation
Cognitive state	MCI=1, NC=2
Gender	Male=1, female=2
Age group (years)	60–64=1, 65–69=2,70–74=3,75–79=4, ≥80=5
Educational level	Illiteracy =1, primary school =2, middle school =3, high school =4, university =5
Occupation	Mental labour =1, physical labour =2
Living condition	Live alone =1, live with family =2
Drinking	Yes = 1, no = 2
Smoking	Yes = 1, no = 2
Drink tea	Yes = 1, no = 2
Sleep time (hours)	<7=1,7–9=2,>9=3
Nap	Yes = 1, no = 2
Physical exercise	Yes = 1, no = 2
Social engagement	Yes = 1, no = 2
Hobbies	Yes = 1, no = 2
High-fat diet	Yes = 1, no = 2

Table 2 Single Factor Analysis of the Influence of Lifestyle on MCI

Research Variables	Category	NC	MCI	Total	MCI Constituent Ratio (%)	χ^2	P
Gender	Male	137	164	301	55	0.662	0.416
	Female	158	166	324	51
Age group (years)	60–64	112	79	191	41	21.083	<0.001
	65–69	78	83	161	52
	70–74	57	76	133	57
	75–79	28	60	88	68
	≥80	20	32	52	62
Educational level	Illiteracy	27	43	70	61	33.547	<0.001
	Primary school	115	163	278	59
	Middle school	69	70	139	50
	High school	48	49	97	51
	University	36	5	41	12
Occupation	Mental labour	121	127	248	51	0.417	0.518
	Physical labour	174	203	377	54
Living condition	Live alone	13	68	81	84	36.235	<0.001
	Live with family	282	262	544	48
Drinking	Yes	94	97	191	51	0.443	0.508
	No	201	233	434	54
Smoking	Yes	79	118	197	60	5.816	0.016
	No	216	212	428	50
Drink tea	Yes	213	117	330	35	84.405	<0.001
	No	82	213	295	72
Sleep time (hours)	<7h	154	175	329	53	0.272	0.873
	7–9h	123	138	261	53
	>9h	18	17	35	49
Nap	Yes	215	194	409	47	13.680	<0.001
	No	80	136	216	63
Physical exercise	Yes	213	170	383	44	28.096	<0.001
	No	82	160	242	66
Social engagement	Yes	178	74	252	29	93.051	<0.001
	No	117	256	373	69
Hobbies	Yes	240	164	404	41	68.302	<0.001
	No	55	166	221	75
High-fat diet	Yes	101	236	337	70	87.116	<0.001
	No	194	94	288	33

Table 3 Binary Logistic Regression Analysis of the Influence of Lifestyle on MCI

Research Variables	β	Walds	P	OR (95% CI)
60–64 years	−1.450	10.184	0.001	0.235 (0.096–0.572)
65–69 years	−1.174	6.653	0.010	0.309 (0.127–0.754)
70–74 years	−0.751	2.647	0.104	0.472 (0.191–1.166)
75–79 years	−0.092	0.034	0.854	0.912 (0.343–2.428)
Illiteracy	2.505	12.704	0.000	12.248 (3.088–48.571)
Primary school	2.194	11.199	0.001	8.975 (2.482–32.452)
Middle school	1.863	7.843	0.005	6.445 (1.749–23.743)
High school	1.854	7.144	0.008	6.386 (1.640–24.873)
Live alone	1.615	14.732	0.000	5.026 (2.204–11.463)
Smoking	0.994	16.544	0.000	2.702 (1.674–4.362)
Drink tea	−1.254	29.943	0.000	0.285 (0.182–0.447)
Nap	−0.569	5.379	0.020	0.566 (0.350–0.916)
Physical exercise	−0.091	0.155	0.694	0.913 (0.581–1.435)
Social engagement	−1.928	64.496	0.000	0.145 (0.091–0.233)
Hobbies	−0.865	13.227	0.000	0.421 (0.264–0.671)
High-fat diet	1.084	22.694	0.000	2.955 (1.892–4.615)

Figure 1 Decision tree model of the influence of lifestyles on MCI. This tree is generated by the software through 10 cross-validations. Each box is numbered sequentially. The blue icon represents MCI, and the red icon represents NC. Each box has its own percentage and specific number of examples. Below each box is the influence factor of the next classification; at the top of each box is the corresponding category of influence factor.

Notes: MCI is mild cognitive impairment, NC is normal cognitive function.

Figure 2 Importance of predictive variables in decision tree model. This figure shows the importance of each influence factor to the result prediction in the decision tree model. As a root node variable, social engagement is the most important predictive variable.

Figure 3 ROC curve of MCI occurrence predicted by decision tree model. The broken line in the figure represents the ability of the decision tree model to predict the occurrence of MCI. The AUC was 0.827, P < 0.001.