Correlations between plasma and PET beta-amyloid levels in individuals with subjective cognitive decline: the Fundació ACE Healthy Brain Initiative (FACEHBI)

Table 4 Summary of logistic regression models and AUROC analysis

Characteristic	Model 1		Model 2a		Model 2b		Model 3		Model 4
Characteristic	OR (95% CI)	p	OR (95% CI)	p	OR (95% CI)	p	OR (95% CI)	p	OR (95% CI)	p
Age	1.091 (1.016–1.172)	0.017	1.114 (1.033–1.202)	0.005	1.097 (1.017–1.183)	0.017	1.113 (1.029–1.205)	0.008	–	–
APOE	–	–	7.319 (2.503–21.401)	2.8E-04	–	–	7.208 (2.431–21.373)	3.7E-4	–	–
Log TP42/40	–	–	–	–	0.131 (0.021–0.819)	0.030	0.126 (0.017–0.944)	0.044	0.133 (0.021–0.829)	0.031
AUROC	0.702		0.806		0.754		0.818		0.681
Youden’s index	0.42		0.54		0.49		0.55		0.42
Cut-off	0.101		0.147		0.115		0.092		0.081
Specificity	69.6		87.3		76.8		77.3		59.1
Sensitivity	72.2		66.7		72.2		77.8		83.3
PPV	19.1		34.3		23.6		25.5		16.7
NPV	96.2		96.3		96.5		97.2		97.2

Logistic regression models were used to assess predictors of FBB-PET SUVR positivity (cut-off > 1.45) after adjustment by selected covariates in 199 participants
Model 1 included only age as a predictor; model 2 requires a blood extraction (APOE ε4 carrier status (0–1) or log TP42/40, model 2a and 2b respectively); model 3 included age, APOE, and log TP42/40, and model 4 only included the target plasma biomarker log TP42/40
The criterion for choosing the operating point along the ROC curve was Youden’s index maximum
AUROC area under the receiver operating characteristic curve, CI confidence interval, NPV negative predictive value, OR odds ratio, PPV positive predictive value, TP total plasma

ISSN: 1758-9193