. 2024 Jul 5;20(9):6183–6204. doi: 10.1002/alz.14100

TABLE 2.

Plasma p‐tau217 mixed‐effects model sets output in healthy control group (Aim 1).

	1 (predictor = sex)			2 (predictor = npscore)			3 (predictor = BMI)			4 (predictor = CKD‐EPI)			5 (predictor = LIBRA)			6 (combined)
Predictors	Estimates	CI	p	Estimates	CI	p	Estimates	CI	p	Estimates	CI	p	Estimates	CI	p	Estimates	CI	p
(Intercept)	−0.15	−0.32 to −0.02	0.076	−0.15	−0.31 to −0.00	0.054	−0.13	−0.30 to −0.04	0.137	−0.14	−0.34 to −0.06	0.178	−0.27	−0.54 to −0.00	0.048	−0.49	−0.78 to −0.21	0.001
c60age	0.04	0.02 to −0.06	<0.001	0.04	0.03 to −0.06	<0.001	0.04	0.02 to −0.06	<0.001	0.04	0.02 to −0.06	<0.001	0.04	0.02 to −0.06	<0.001	0.04	0.02 to −0.06	<0.001
c60age²	0.00	0.00 to −0.00	0.030	0.00	0.00 to −0.00	0.034	0.00	0.00 to −0.00	0.031	0.00	0.00 to −0.00	0.026	0.00	0.00 to −0.00	0.028	0.00	0.00 to −0.00	0.033
Male	0.31	0.02 to −0.60	0.035													0.33	0.05 to −0.61	0.022
npscore				0.19	0.06 to −0.33	0.006										0.21	0.07 to −0.34	0.003
BMI [obese]							0.22	−0.06 to −0.51	0.129
CKD EPI [Stage 2]										0.15	−0.13 to −0.42	0.294
CKD EPI [Stage 3]										0.35	−0.53 to 1.23	0.436
LIBRA [Moderate]													0.20	−0.15 to −0.55	0.255	0.21	−0.13 to −0.55	0.236
LIBRA [High]													0.37	0.03 to −0.72	0.033	0.41	0.08 to −0.75	0.015
Random Effects
σ²	0.38			0.38			0.38			0.38			0.38			0.38
τ₀₀	0.70_Reggieid			0.68_Reggieid			0.70_Reggieid			0.71_Reggieid			0.70_Reggieid			0.65_Reggieid
τ₁₁	0.00_{Reggieid.c60age}			0.00_{Reggieid.c60age}			0.00_{Reggieid.c60age}			0.00_{Reggieid.c60age}			0.00_{Reggieid.c60age}			0.00_{Reggieid.c60age}
ρ₀₁	0.20_Reggieid			0.18_Reggieid			0.20_Reggieid			0.23_Reggieid			0.22_Reggieid			0.19_Reggieid
ICC	0.74			0.73			0.74			0.74			0.74			0.72
N	222_Reggieid			222_Reggieid			222_Reggieid			222_Reggieid			222_Reggieid			222_Reggieid
Observations	665			665			665			665			665			665
Marginal R ²/Conditional R ²	0.106/0.763			0.103/0.759			0.097/0.764			0.098/0.766			0.104/0.765			0.140/0.758
AICc	1750.1			1747.2			1752.3			1755.1			1752.0			1742.3
$Δ$ AICc	−2.44			−5.37			−0.26			2.62			−0.54			−10.18

Note: The base model is age fixed effects up to cubic polynomial (retaining highest order significant term and lower order terms; centered at age 60 (c60)) and random effects. Models 1–5 started with predictor^*age included and then removed if non‐significant (NS). Model 6 brings in significant main effects and interactions from Models 1–5, removes NS interactions sequentially (least significant out first) until only significant interactions (and their supporting main effects) or significant main effects (if no corresponding interactions are significant) remain. Change in Akaike information criterion ΔAICc is calculated relative to the base model; negative numbers indicate a better fit in the expanded model. Bold values are statistically significant. npscore is the Apolipoprotein E neuropathology‐based risk score; BMI body mass index; CKD EPI chronic kidney disease epidemiology collaboration; LIBRA Lifestyle for Brainhealth Index; ICC intraclass correlation coefficient; Reggieid is the person‐level study number.