Sensitivity and specificity

Sensitivity and specificity are a recurring theme in medicine and pathology.

Definitions

Sensitivity

$Sensitivity=TP/(TP+FN)$

Specificity

$Specificity=TN/(TN+FP)$

Notes:

• TP = true positive.
• FN = false negative.
• TN = true negative.
• FP = false positive.

Memory device:

• "SpPins and SnNouts" = specific positive test rules in, sensitive negative test rules out.

See also

• Basics.
• Positive predictive value.
• Negative predictive value.

External links

• CEBM (ktclearinghouse.ca).