Table 1:

Participant characteristics at baseline. Factors included in analyses are shown in bold.

	Total (n = 137)	Aβ42/Aβ40 − (n = 83)	Aβ42/Aβ40 +(n = 54)a	Testa
Age, years	73.80 ±4.76	72.84 ±4.51	75.28 ±4.79	p < 0.01**
Sex, N = female, %	62 (45.26)	41 (49.40)	21 (38.89)	p = 0.292
Education, years	16.50 ±2.27	16.25 ±2.27	16.87 ±2.25	p = 0.120
Raceb, N = White, %	120 (87.59)	69 (83.13)	51 (94.44)	p = 0.064
APOE ε4+ carrier, N, %	47 (34.31)	13 (15.66)	34 (62.96)	p < 0.001***
Biomarkers
CSF: Aβ 42 /Aβ 40	0.074 ±0.023	0.091±0.008	0.048 ±0.010	p < 0.001***
CSF: t-Tau	353.76 ±179.72	295.30 ±157.17	443.62 ±176.31	p < 0.001***
CSF: p-Tau	46.91±22.82	36.28 ±14.80	63.25 ±23.42	p < 0.001***
MRI c : Hippocampal volume (normalized), cm 3	7.48 ±0.95	7.47 ±0.94	7.50 ±0.96	p = 0.874
Driving
Trips with speeding, %	9.02 ±9.29	9.18 ±8.69	8.80 ±10.21	p = 0.821
Trips with hard braking, %	9.11 ±7.28	9.79 ±7.85	8.06 ±6.22	p = 0.153
Trips with hard acceleration, %	4.11 ±6.67	4.03 ±6.82	4.24 ±6.49	p = 0.863
Trips with any adverse driving events, %	18.53 ±12.76	19.16 ±12.43	17.57 ±13.31	p = 0.485
Trips, N	2866.86 ±1615.77	3033.22 ±1656.63	2611.17 ±1530.75	p = 0.130
Cognitive assessment
Free & Cued Serial Reminding Task, free recall score	30.28 ±6.76	31.80 ±6.21	27.94 ±6.96	p < 0.01**
Animal Fluency, total animals named	21.09 ±4.86	21.34 ±4.97	20.72 ±4.71	p = 0.466
Trailmaking A, seconds to complete	30.98 ±9.72	29.96 ±8.84	32.54 ±10.83	p = 0.148
Trailmaking B, seconds to complete	75.93 ±29.18	75.80 ±30.11	76.15 ±27.96	p = 0.944
Composite score	−0.15 ±0.72	−0.05 ±0.73	−0.31 ±0.70	p < 0.05*

^aMeans were compared using t-tests. Frequencies were compared using Fisher’s exact test.

^bThe sample contains only Black and White races.

^cData only available for 106 participants. Biomarker negative = 65 (61.32%), biomarker positive = 41 (38.68%).

APOE= Apolipoprotein E; CSF = Cerebrospinal fluid; MRI = Magnetic Resonance Imaging.

^*p<0.05;

^**p<0.01;

^***p<0.001