Table 3: Infrequency Index (CII) Operating Characteristics at Various Cut Scores.

 

Cut Score

Sn

Sp

PPP

NPP

Hit Rate

IPPP

INPP

Overall CII

³ 21

0.36

0.85

0.44

0.80

0.73

0.19

0.05

 

³ 22

0.32

0.89

0.49

0.80

0.75

0.24

0.05

 

³ 23

0.26

0.96

0.68

0.80

0.79

0.43

0.05

Paper CII

³ 21

0.34

0.85

0.43

0.79

0.72

0.18

0.04

 

³ 22

0.26

0.85

0.37

0.78

0.70

0.12

0.03

 

³ 23

0.20

1.00

1.00

0.79

0.80

0.75

0.04

Online CII

³ 21

0.39

0.86

0.48

0.81

0.74

0.23

0.06

 

³ 22

0.39

0.93

0.65

0.82

0.80

0.40

0.07

 

³ 23

0.32

0.93

0.60

0.80

0.78

0.35

0.05

Note. Sn = sensitivity; Sp = specificity; PPP = positive predictive power; NPP = negative predictive power; IPPP = incremental positive predictive power; INPP = incremental negative predictive power.