Understanding the design of test accuracy studies

Test accuracy studies evaluate the performance of a medical test: to what extent the test is able to distinguish patients with the target condition from those without. This chapter provides an overview of the most common designs used to assess test accuracy. It provides a description of the basic study design for evaluating the accuracy of a single test, followed by a description of variations of this basic study design. The chapter then identifies various types of reference standards and describes designs for studies to evaluate and compare the accuracy of two or more tests. In the basic design for a test accuracy study, a single group of consecutive participants is included, all suspected of having the target condition. A variation on the basic study design, which is commonly observed in test accuracy studies, is the study that uses two or more sets of eligibility criteria.