Calculate Sensitivity and Specificity of ELISA in a population screened for HIV. Data is given below HIV Present HIV Absent ELISA +ve 80 40 ELISA -ve 20 60
HIV Present HIV Absent ELISA + ve 80 = a 40 =b ELISA -ve 20 = c 60 =d Sensitivity = a/a+c x 100 = 80/100 X 100 = 80% Specificity = d/ b+d x 100 = 60/100 X 100 = 60% PPV 80/120 X 100 = 66% NPV 60/80 X 100 = 75%
60%, 80%
80%, 60%
66.6%, 75%
75%, 66.6%
Sensitivity, Specificity, PPV, NPV