specificity (definition)
Last edited 09/2023 and last reviewed 09/2023
The specificity of a test can be described as the proportion of true negatives it detects of all the patients without the target disorder.
It is thus the proportion of patients without the target disorder who have a negative test result (specificity is the proportion of people who do not have a target disease that are tested negative).
All negatives are the sum of (detected) true negatives (TN) and (misdiagnosed) false positives (FP).
| Target Disorder Present | Target Disorder Absent | |
| Test result positive | True Positive (TP) | False Positive (FP) |
| Test result negative | False Negative (FN) | True Negative (TN) |
Specificity is therefore:
- TN / (TN + FP) x 100%