Key summaries
Open Access

Table 4

Terms of the sensitivity and specificity measurements.

Retreat case Non-retreat case
Test positive to predict retreat cases True Positives (TP) False Positives (FP) Total test positives
Retreat cases Retreat cases
a (TP) b (FP) a + b
Test positive to predict non-retreat cases False Negatives (FN) True Negatives (TN) Total test negatives
Retreat cases Retreat cases
c (FN) d (TN) c + d
Total retreat cases Total non-retreat cases Total population
a + c b + d a + b + c + d