TABLE 5.

Relationship between plasma biomarker levels and Aβ‐PET positivity status.

	Base							Adj
	N	OR1	SE1	Z	95% CI1	p	q	N	OR1	SE1	Z	95% CI1	p	q
NfL	140	1.07	0.31	0.23	0.57, 1.96	0.819	0.936	81	1.13	0.44	0.28	0.45, 2.62	0.778	0.936
GFAP	140	1.97	0.31	2.2	1.11, 3.75	0.020	0.053	81	1.59	0.42	1.12	0.74, 3.85	0.244	0.434
Aβ42/40	140	0.49	0.24	−2.9	0.30, 0.78	0.002	0.008	81	0.77	0.3	−0.9	0.43, 1.43	0.379	0.606
p‐tau181	140	2.03	0.27	2.61	1.26, 3.68	0.003	0.009	81	5.2	0.51	3.23	2.10, 15.7	<0.001	0.001

	F‐Adj							F‐Adj‐Dx
	N	OR1	SE1	Z	95% CI1	p	q	N	OR1	SE1	Z	95% CI1	p	q
NfL	77	1.01	0.5	0.02	0.34, 2.65	0.988	0.988	77	0.74	0.62	−0.5	0.20, 2.28	0.626	0.911
GFAP	77	1.91	0.49	1.32	0.77, 5.50	0.168	0.336	77	2.01	0.51	1.37	0.74, 5.94	0.166	0.336
Aβ42/40	77	1.13	0.43	0.29	0.52, 2.86	0.770	0.936	77	1.05	0.5	0.11	0.44, 3.18	0.916	0.977
p‐tau181	77	4.7	0.55	2.8	1.82, 16.1	<0.001	<0.001	77	5.61	0.66	2.63	1.94, 26.0	<0.001	<0.001

Note: Logistic regression models assessed associations between plasma biomarker levels and amyloid PET positivity status before and after adjusting for covariates and comorbid health complications. Here, all plasma biomarkers were entered simultaneously to predict amyloid PET positivity status. All continuous predictors were z‐scored prior to analysis.

Abbreviations: Aβ, Amyloid‐Beta; Adj, linear models adjusted for comorbidities (eGFR, BMI); Base, baseline model with all plasma biomarkers as predictors; F‐Adj, linear models adjusted for comorbidities (eGFR, BMI) & covariates (Age, Sex, Race, Education, APOE‐ε4 status); F‐Adj‐Dx., Full adjusted model plus diagnosis; CI, confidence interval; NfL, neurofilament light chain; GFAP, glial acid fibrillary protein; p‐Tau, Phosphorylated Tau at Threonine 181; OR, odds‐ratio; SE, standard error; q, Benjamini‐Hochberg false discovery rate.