Table 4.

Sensitivity, specificity, PPV, and NPV of variables for predicting ecchymosis after TKA.

Parameters	AUC (95%CI)	Cut-off	Sensitivity (95%CI)	Specificity (95%CI)	PPV (%)	NPV (%)	LR+	LR–	Accuracy (%)
ΔCI	0.794 (0.730, 0.849)	0.1805	74.55 (61.0, 85.3)	72.99 (64.7, 80.2)	52.6 (44.7, 60.3)	87.7 (81.8, 91.9)	2.76 (2.0, 3.8)	0.35 (0.2, 0.6)	73.4375
Hidden blood	0.681 (0.610, 0.746)	311.63	60.00 (45.9, 73.0)	76.64 (68.7, 83.4)	50.8 (41.5, 59.9)	82.7 (77.3, 87.0)	2.57 (1.8, 3.7)	0.52 (0.4, 0.7)	71.3542
loss (mL)

ΔCI, change of coagulation index. CI, confidence interval; PPV, positive predictive value; NPV, negative predictive value. TKA, total knee arthroplasty.