The specificity of a test is the number of true-negative test results divided by the number of all patients without the disease.
specificity =
= (d / (b + d))
where:
• d = true negatives
• (b + d) = false positives + true negatives = all people without disease
Comments:
• The better the sPecificity of the test, the fewer the false Positives.
• The specificity is the true negative rate.