The Cribari Matric is used to assess undertriage and overtriage in a trauma center. It is comparable to the true positive and false negative rates.
Axes for 2x2 matrix:
(1) major trauma (ISS > 15, positive NFTI, or other criteria) vs minor trauma
(2) full trauma team activation or not
|
Major Trauma (ISS > 15)
|
Minor Trauma (ISS <= 15)
|
Full Team Activated
|
a
|
b
|
Full Team Not Activated
|
c
|
d
|
undertriage = false negative rate =
= (number with full team not activated AND major trauma) / (total number with full trauma team not activated) =
= c / (c + d)
overtriage = false positive rate =
= (number activated and minor trauma) / (total with full trauma team activated) =
= b / (a + b)
correctly triaged =
= (a + d) / (a + b + c + d)