Understanding test accuracy measures

Before undertaking a test accuracy meta-analysis, it is necessary to understand the distinct types of data, as well as the presentation and meaning of statistical summaries of test accuracy reported in the primary studies. The accuracy of a test can be presented using several individual measures or pairs of measures. This chapter explains and illustrates the most commonly encountered measures. It provides an overview of types of test data, followed by how to deal with inconclusive test results and a summary of issues in defining the target condition. The chapter then focuses on analysis, including the basic analysis of a primary test accuracy study, thresholds for defining test positivity and their relationship with estimates of test accuracy, generating and understanding receiver operating characteristic curves, and concluding with an analysis of comparative accuracy studies.