Calculating the important features of screening test

FeatureFormulaData (see table 3)Value
Sensitivitya/ (a+c)6/2722.2%
Specificityd/ (b+d)966/97399.3%
Positive predictive valuea/ (a+b)6/1346.2%
Negative predictive valued/ (c+d)966/97397.8%
Accuracy(a+d)/ (a+b+c+d)972/100097.2%
Likelihood ratio:
Positive testSensitivity/ (l-specificity)22.2/0.732
Negative test(l-sensitivity)/specificity77.8/99.0.783