Measure

Sensitivity^{†}

Specificity^{†}

PPV^{†}

NPV^{†}



n

%

(se)

n

%

(se)

n

%

(se)

n

%

(se)


3month survival

2974/2984

99.7

(0.1)

68/2639

2.6

(0.3)

2974/5545

53.6

(0.7)

68/78

87.2

(3.8)

6month survival

2329/2360

98.7

(0.2)

207/3263

6.3

(0.4)

2329/5385

43.3

(0.7)

207/238

87.0

(2.2)

1year survival

1762/1823

96.7

(0.4)

543/3800

14.3

(0.6)

1762/5019

35.1

(0.7)

543/604

89.9

(1.2)

2year survival

1235/1329

92.9

(0.7)

1099/4294

25.6

(0.7)

1235/4430

27.9

(0.7)

1099/1193

92.1

(0.8)

 PPV: positive predictive value
 NPV: negative predictive value
 se: standard error

* As 10% was chosen as the cutoff value for predicted probability, patients with a predicted probability of survival < 10% were classified as a group that would die before the end of observation period, and those with a predicted probability of survival > = 10% were classified as a group that would survive the whole observation period. By comparison of predicted outcomes with actual outcomes, we further calculated the four measures for reflecting the quality of predictions in different perspectives.

^{†} The formulae for these measures are below:
 sensitivity = (the number of patients with a predicted probability of survival > = 10%)/(the number of patients who actually survive the whole observation period);
 specificity = (the number of patients with a predicted probability of survival < 10%)/(the number of patients who actually died before the end of observation period);
 PPV = (the number of patients who actually survive the whole observation period)/(the number of patients with a predicted probability of survival > = 10%);
 NPV = (the number of patients who actually died before the end of observation period)/(the number of patients with a predicted probability of survival < 10%).