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(Created page with "Any single test or investigation has a certain characteristics which are important to know about. == True and false positive and negative == When researching a certain test's characteristics and usefulness in diagnosing a certain disorder, one would perform the test on both healthy people and people with the disorder. A good test will be positive in most people with the disorder and negative in most people without the disorder. However, because no test is perfect, the t...") |
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As with PPV, the negative predictive value of a test depends not only on the test's characteristics but also the pre-test probability of the disorder. However, in contrast to PPV, NPV ''decreases'' as the prevalence increases. As such, even if the test is really accurate and has a high specificity and sensitivity, the test may have a low negative predictive value regardless if the prevalence is high (the disease is common). | As with PPV, the negative predictive value of a test depends not only on the test's characteristics but also the pre-test probability of the disorder. However, in contrast to PPV, NPV ''decreases'' as the prevalence increases. As such, even if the test is really accurate and has a high specificity and sensitivity, the test may have a low negative predictive value regardless if the prevalence is high (the disease is common). | ||
[[Category:Public Health]] | |||
[[Category:Laboratory Medicine]] |