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SEQUENTIAL TESTING PPV SERIAL
SEQUENTIAL TESTING PPV SERIES

A false positive result could also be the result of a sample being mislabelled, mixed up with another person’s, or some other clerical or technical error. When the result is borderline, experienced staff give more consistently accurate results. Depending on the testing device, reading the test result may rely on subjective interpretation. There are other reasons why a test may give a false positive result. The latest news and research on types of HIV tests Tests are not meant to react to other types of antibodies, but it sometimes happens. The main cause of false positive results is that the test has detected antibodies, but they are not antibodies to HIV – they are antibodies to another substance or infection. These are proteins produced by the immune system in response to a foreign substance, such as HIV. HIV tests are based on the detection of antibodies to HIV.

SEQUENTIAL TESTING PPV SERIES

Because it is upsetting and disturbing to receive a false positive result, preliminary positive (‘reactive’) results must always be verified with a series of confirmatory tests. While many HIV tests are extremely accurate, they do not achieve 100% accuracy.Ī false positive is a test result that says a person has HIV when, in fact, they do not have it. The ideal HIV screening test would correctly identify all HIV-positive and HIV-negative individuals 100% of the time.

A diagnosis of HIV is never made on the basis of a single test result.

To ensure accurate diagnosis, a sequence of confirmatory tests is used to verify all reactive results.

In settings where very few people have HIV, a higher proportion of reactive results will be false positives.

Tests always produce a small number of false positive results.

Specificity is higher than for either test alone. Sensitivity is higher than for either test alone.įor A "and" B, if A is negative, then the second test does not need to be performed.

sensitivity: (A) sen + x (B) senįor A "or" B, if A is positive, then the second test does not need to be performed.

SEQUENTIAL TESTING PPV SERIAL

Serial testing is more useful in some clinical scenarios to potentially eliminate the need for the second test. the overall specificity is greater than for either alone.the overall sensitivity is less than for either alone.When two studies are combined in an "and" manner: the overall specificity is less than for either alone.the overall sensitivity is greater than for either alone.When two studies are combined in an "or" manner: if either test is positive, then the disease or condition is present.if both tests are positive, then the disease or condition is present.serial: studies are performed sequentially, with the second study dependent on the results of the first.parallel: studies are performed at the same time or at approximately the same time.These two tests can be interpreted in an "and" or an "or" manner. Sensitivity and specificity of multiple tests is a common statistical problem in radiology because frequently two tests (A and B) with different sensitivities and specificities are combined to diagnose a particular disease or condition.