The probability of a test detecting a truly positive person from the population of diseased is the
Specificity of the test
Positive predictive value of the test
Sensitivity of the test
Likelihood ratio
Sensitivity of a screening test detects: true positives among all diseased.
Specificity of a screening test detects: true negatives among all healthy.
PPV detects: true positives among all those who are positive on a screening test
NPV detects: true negatives among all those who are negative on a screening test.