Positive predictive value

Positive predictive value is how convincing or believable a positive test result is in a given population

The positive predictive value (PPV) of a test relates to how believable a positive test is within a given population. As the prevalence of a disease state increases, the positive predictive value of a diagnostic test will increase due to the existence of more cases being picked up in the population.
For positive predictive value, researchers focus on this part of the 2x2 table:
Positive predictive value (PPV) is focused on the participants that tested positive with the diagnostic test.
Everyone in the calculation tested "positive" using our diagnostic test. Thus, researchers can calculate proportion of people with the disease as measured by "gold standard" that tested "positive" using our test. With higher values of PPV, the "believability" or confidence of the test increases. 
Here is the formula for positive predictive value:
Positive predictive value (PPV) is a calculation related to how believable a positive test result is in a given population. As prevalence of a disease state increases, PPV will increase.
Positive Predictive Value (PPV)
Click on the Negative Predictive Value button to continue.
Negative Predictive Value
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