Table 2 Preoperative prediction of blood transfusion with a sensitivity, specificity, precision, accuracy, and F1 score of 0.22, 0.37, 0.15, 0.43, and 0.18 retrospectively

Transfusion

True-positive

False-negative

Ja /Ja

Ja/Nein

31

0

False positive

True negative

Nein/Ja

Nein/Nein

175

103

Sensitivity = true positive/ (true positive + false negative)

Sensitivity = 31/(31 + 103) = 31/144 = 0.22

Specificity = true negative/(true negative + false positive)

Specificity = 103/103 + 175 = 0.37

Precision = true positive / (true positive + false positive)

Precision = 31/(31 + 175) = 0.15

Accuracy = (true positive + true negative)/total number of prediction

Accuracy = 31 + 103/309 = 0.43

F1 Score = 0.18