A high Z-score might increase the positive predictive value of cell-free noninvasive prenatal testing for singleton-pregnant women

Figures & data

Table 1. Performance of NIPT-positive results for T21/T18/T13 among different groups.

	TP			FP			Total TP	Total FP	PPV
	T21	T18	T13	T21	T18	T13
Group 3 ≤ Z < 6	5	3	1	2	4	3	9	9	50.00%
Group 6 ≤ Z < 10	28	12	4	3	2	3	44	8	84.62%
Group Z ≥ 10	61	10	2	4	0	6	73	10	87.95%
Total	94	25	7	9	6	12	126	27	82.35%

TP: true positive; FP: false positive; PPV: positive predictive value; T: trisomy.

Table 2. Multivariable analysis between Z-score and PPV for T21, T18, and T13.

Group	OR	95% CI	p
T21	1.051	0.935, 1.181	.407
T18	1.773	1.102, 2.854	.018
T13	0.891	0.692, 1.147	.371

OR: odds ratio; CI: confidence interval.

Figure 1. Structural equation analyses. (A) True positive trisomy (T) 21. (B) False positive T21. (C) True positive T18. (D) False positive T18. (E) True positive T13. (F) False positive T13.

Data availability statement

This article includes all the relevant data generated or analyzed during this study.