Table 4.

Variable Importance (VIMP) ranking for cognitive impairment (Part A) and dementia (Part B).

Rank	A: Cognitive Impairment	Irel		B: Dementia	Irel
1	African American	1.00		BMI Slope	0.42
2	Wealth	0.59		Emotional Distress	0.40
3	Education	0.57		Diabetes	0.34
4	BMI Slope	0.33		African American	0.33
5	Subjective Health	0.27		Childhood Traumas	0.23
6	Emotional Distress	0.27		Hemoglobin A1C	0.20
7	Ethnicity (Hispanic)	0.22		Education	0.19
8	Grip Strength	0.17		Life Satisfaction	0.17
9	Childhood Traumas	0.16		Ethnicity (Hispanic)	0.15
10	Smoking	0.15		Childhood Health	0.15
11	Marital Status	0.13		Funct. Limitations	0.13
12	Social Contact	0.11		Subjective Health	0.10
13	Cystatin C	0.10		Stroke	0.09
14	Income	0.08		Social Contact	0.08
15	Cholesterol	0.07		Activity Total	0.07
16	Work	0.07		Openness	0.07
17	Childhood Health	0.06		Hearing	0.07
18	Polygenic Score with APOE ε4	0.05		Cystatin C	0.06
19	Openness	0.05		Purpose in Life	0.06
20	Functional Limitations	0.05		Alcohol	0.06
21	Hemoglobin A1C	0.04		Income	0.05
22	Race (Other)	0.03		Positive Affect	0.05
23	Conscientiousness	0.03		Lifetime Traumas	0.04
24	Agreeableness	0.02		Work	0.03
25	Cancer	0.02		Marital Status	0.03
26	Alcohol	0.02		Agreeableness	0.03
27	Gender	0.02		Hypertension	0.02
28	Lifetime Traumas	0.02		Moderate Activity	0.02
29	Hearing	0.01		Wealth	0.01
30	Vigorous Activity	0.01		Polygenic Score with APOE ε4	0.01
31	Optimism	0.01		Mild Activity	0.01
32	Mild Activity	0.01		Conscientiousness	0.01
33	Polygenic Score without APOE ε4	0.01		Optimism	0.01
34	Activity Total	0.01		Highest BMI	0.01
35	Extraversion	0.00		Hear Aid	0.00
36	Purpose in Life	0.00		Type Home	0.00
37	Diabetes	0.00		Extraversion	−0.01
38	Life Satisfaction	0.00		Vigorous Activity	−0.01
39	High Density Lipoprotein	0.00		Race (Other)	−0.01
40	Type Home	0.00		Gender	−0.01
41	Hear Aid	0.00		Polygenic Score without APOE ε4	−0.01
42	Stroke	−0.01		High Density Lipoprotein	−0.02
43	Heart Disease	−0.01		Sleep Medication	−0.02
44	Highest BMI	−0.01		Grip Strength	−0.02
45	Moderate Activity	−0.01		Heart Disease	−0.02
46	Sleep Medication	−0.01		Cancer	−0.04
47	Hypertension	−0.01		Cholesterol	−0.04
48	BMI	−0.01		BMI	−0.05
49	Waist Circumference	−0.02		C Reactive Protein	−0.07
50	Positive Affect	−0.02		Smoking	−0.07
51	C Reactive Protein	−0.04		Waist Circumference	−0.07
52	Age at Baseline	−0.40		Age at Baseline	−1.00

Note. Random forest survival analysis (RFSA) was conducted in a subsample (n = 4,990) separately for cognitive impairment and dementia. Relative importance (I_rel) refers to the relative importance in predicting risk of cognitive impairment and dementia, respectively.