February, 2003
© 2000, 2001, 2003 Scott S. Emerson, M.D., Ph.D.
Diagnostic Testing: 3
Predictive Values of Positive and Negative
We are actually interested in the diagnostic utility of the test: Predictive value of positive and negative
Predictive value of a positive test: Probability of disease when test is positive
·Pr ( D | + )
·
Predictive value of a negative test: Probability of health when test is negative
·Pr ( H | - )