Placental growth factor for the prognosis of women with preeclampsia (fullPIERS model extension): context matters

Table 4 Reclassification Table for Extended Model with PlGF (fullPIERS plus PlGF)

fullPIERS Model without PlGF
Predicted probability	Women with events	Women without events	Total
0 to 9%	37	475	512
≥ 10%	7	22	29
Total	44	497	541
fullPIERS model with PlGF
Predicted probability	Women with events	Women without events	Total
0 to 9%	29	416	445
≥ 10%	15	81	96
Total	44	497	541

Net reclassification index (NRI) calculation
Original fullPIERS model
Sensitivity = 37/44*100 = 84.1%; Specificity = 22/497*100 = 4.4%
fullPIERS model + PlGF (extended fullPIERS model)
Sensitivity = 29/44*100 = 65.9%; Specificity =81/497*100 = 16.3%
Improved sensitivity = 65.9–84.3% = −18.4%; Improved specificity = 16.3–4.4% = 11.9%
NRI = Improved sensitivity + Improved specificity = − 18.4% + 9.7% = −8.7%

ISSN: 1471-2393