
Medmastery: PPV and prevalence
Franz Wiesbauer looks at how a doctor can work out the probability of disease when confronted with a positive or a negative test result and how the prevalence of a given disease affects this probability.

Franz Wiesbauer looks at how a doctor can work out the probability of disease when confronted with a positive or a negative test result and how the prevalence of a given disease affects this probability.

Diagnostic tests and terms: sensitivity; specificity; positive predictive value; negative predictive value; likelihood ratio; receiver operator characteristic curve (ROC curve)