| Target disorder |
---|
Present | Absent |
---|
Diagnostic test result | Positive | True positive a | False positive b |
Negative | False negative c | True negative d |
- Sensitivity a/(a + c)
- Specificity d/(b + d)
- Positive predictive value a/(a + b)
- Negative predictive value d/(c + d)
- Prevalence (pre-test probability) (a + c)/(a + b + c + d)
- Positive likelihood ratio (LR+) sensitivity/(1-specificity)
- Negative likelihood ratio (LR−) (1–sensitivity)/specificity