A step-by-step guide to the systematic review and meta-analysis of diagnostic and prognostic test accuracy evaluations

In evidence-based medicine (EBM), systematic reviews and meta-analyses have been widely applied in biological and medical research. Moreover, the most popular application of meta-analyses in this field may be to examine diagnostic (sensitivity and specificity) and prognostic (hazard ratio (HR) and its variance, standard error (SE) or confidence interval (CI)) test accuracy. However, conducting such analyses requires not only a great deal of time but also an advanced professional knowledge of mathematics, statistics and computer science. Regarding the practical application of meta-analyses for diagnostic and prognostic markers, the majority of users are clinicians and biologists, most of whom are not skilled at mathematics and computer science in particular. Hence, it is necessary for these users to have a simplified version of a protocol to help them to quickly conduct meta-analyses of the accuracy of diagnostic and prognostic tests. The aim of this paper is to enable individuals who have never performed a meta-analysis to do so from scratch. The paper does not attempt to serve as a comprehensive theoretical guide but instead describes one rigorous way of conducting a meta-analysis for diagnostic and prognostic markers. Investigators who follow the outlined methods should be able to understand the basic ideas behind the steps taken, the meaning of the meta-analysis results obtained for diagnostic and prognostic markers and the scope of questions that can be answered with Systematic Reviews and Meta-Analyses (SRMA). The presented protocols have been successfully tested by clinicians without meta-analysis experience.