what is prognosis test

A prognostic test is used to predict a patients likelihood of developing a disease or experiencing a medical event. Unlike diagnostic tests, which diagnose specific diseases and conditions, prognostic tests predict something, such as the likely progress of a disease (prognosis), such as the likelihood of experiencing repeated flares or the likelihood of developing complications. Prognostic markers, also known as biomarkers, are characteristics that help to identify or categorize people with different risks of specific future outcomes. The clinical usefulness of a prognostic test depends largely on its ability to sort patients into different prognostic groups. In some contexts, it may be informative to categorize subjects as those who did or did not experience the predicted outcome within a specified time interval, and then look back to categorize the results of the prognostic test. A systematic review of a prognostic test could assess the accuracy of the prognostic test by calculating the sensitivity and specificity and predictive values for that point in time.