Test result | Disease state | ||
---|---|---|---|
Present | Absent | Total | |
Sensitivity = a/(a+c). | |||
Specificity = d/(b+d). | |||
Positive predictive value = a/(a+b). | |||
Negative predictive value = d/(c+d). | |||
Positive likelihood ratio = sensitivity/(1−specificity). | |||
Negative likelihood ration = (1−sensitivity)/specificity. | |||
Positive | A | b | a+b |
Negative | C | d | c+d |
Total | a+c | b+d | a+b+c+d |