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. Author manuscript; available in PMC: 2017 Mar 22.
Published in final edited form as: Hypertension. 2017 Feb 6;69(4):731–738. doi: 10.1161/HYPERTENSIONAHA.116.08620

Table 2.

Screening statistics for the primary outcomes by maternal risk status using the threshold of sFlt-1:PlGF ratio of >38 at 28wkGA and 36wkGA.

28wkGA*
Preeclampsia with preterm delivery		 36wkGA*
Preeclampsia with severe features
Screening statistic All High risk Low risk All High risk Low risk
Sensitivity (%) 23.1
(6.9-39.3)		 22.2
(3.0-41.4)		 25.0
(0.0-55.0)		 54.7
(45.2-64.2)		 53.3
(40.7-66.0)		 56.5
(42.2-70.8)
Specificity (%) 99.7
(99.5-99.8)		 98.8
(98.0-99.6)		 99.9
(99.8-100.0)		 86.2
(85.0-87.3)		 80.6
(77.5-83.6)		 87.4
(86.2-88.5)
Positive predictive value (%) 31.6
(10.7-52.5)		 30.8
(5.7-55.9)		 33.3
(0.0-71.1)		 10.2
(7.7-12.7)		 20.3
(14.0-26.5)		 6.4
(4.0-8.7)
Negative predictive value (%) 99.5
(99.3-99.7)		 98.2
(97.2-99.1)		 99.8
(99.7-100.0)		 98.5
(98.1-98.9)		 94.9
(93.1-96.7)		 99.2
(98.9-99.6)
Positive likelihood ratio† 70.3
(29.0-170.8)		 18.6
(6.3-54.9)		 200.6
(42.6-944.1)		 4.0
(3.3-4.8)		 2.7
(2.1-3.6)		 4.5
(3.4-5.9)
Negative likelihood ratio‡ 0.77
(0.63-0.95)		 0.79
(0.61-1.01)		 0.75
(0.50-1.12)		 0.53
(0.43-0.65)		 0.58
(0.44-0.76)		 0.50
(0.36-0.69)
*

wkGA denotes weeks of gestational age (of measurement of the sFlt-1:PlGF ratio).

†

Positive likelihood ratio was defined as the ratio between the proportions of screen positives among cases and screen positives among non-cases ([S+|D+]/[S+|D-]).

‡

Negative likelihood ratio was defined as the ratio between the proportions of screen negatives among cases and screen negatives among non-cases ([S-|D+]/[S-|D-]).

See Supplemental Tables for raw data from 2x2 tables.