The interpretation of diagnostic tests

Laboratory diagnostic tests are central in the practice of modern medicine. Common uses include screening a specific population for evidence of disease and confirming or ruling out a tentative diagnosis in an individual patient. The interpretation of a diagnostic test result depends on both the ability of the test to distinguish diseased from nondiseased subjects and the particular characteristics of the patient and setting in which the test is being used. This article reviews statistical methodology for assessing laboratory diagnostic test accuracy and interpreting individual test results, with an emphasis on diagnostic tests that yield a continuous measurement. The article begins with a summary of basic concepts and terminology, then briefly discusses study design and reviews methods for assessing the accuracy of a single diagnostic test, comparing the accuracy of two or more diagnostic tests and interpreting individual test results.