Arq. Bras. Cardiol. 2017; 109(2): 94-96
Calcium Score Use in Isolation in Acute Chest Pain Setting – Is it Sufficient?
DOI: 10.5935/abc.20170116
The clinical usefulness of any test in Medicine depends on the population studied, because even an accurate test will yield no benefit if applied to the wrong population. While sensitivity and specificity are characteristics inherent in the diagnostic method, the individual probability of having a disease when the test is positive (positive predictive value, PPV) and the probability of not having the disease when the test is negative (negative predictive value, NPV) depend on the disease prevalence in the population and the individual probability of having the disease before undergoing the test, the pretest probability.
The PPV and NPV are the information that matters for clinicians. In the presence of a positive test, clinicians are interested in the patient’s real probability of having the disease. However, in the presence of a negative test, Clinicians want to know the true probability of the disease even with the negative result. Thus, PPV and NPV should be considered before requesting a test, because some cases a positive test might not sufficient to confirm the presence of disease, while a negative test might not be able to exclude it safely.
[…]
509