Table 4.

Operating Characteristics of Algorithms

	Sensitivity	Specificity	PPV	NPV	+LR	−LR
PERC	1.00 (0.78–1.00)	0.10 (0.06–0.17)	0.13 (0.08–0.20)	1.00 (0.73–1.00)	1.12 (1.05–1.18)	0
Wells/D-dimer	1.00 (0.78–1.00)	0.16 (0.10–0.23)	0.14 (0.09–0.21)	1.00 (0.81–1.00)	1.19 (1.10–1.28)	0

PERC = Pulmonary embolism rule out criteria; PPV = positive predictive value; NPV = negative predictive value; +LR = positive likelihood ratio; −LR = negative likelihood ratio

95% Confidence Intervals are shown in parentheses