Graphical enhancements to summary receiver operating characteristic plots to facilitate the analysis and reporting of meta-analysis of diagnostic test accuracy data

Diagnostic test accuracy (DTA) systematic reviews are conducted to summarize evidence on the accuracy of a diagnostic test including a critical evaluation of the primary studies. Where appropriate, the evidence is meta-analyzed to obtain pooled estimates of effectiveness.In this study, we reviewed and critiqued three DTA guidance documents with respect to the graphical presentation of DTA meta-analysis results. All three documents recommended the use of two forms of graphical presentation: (a) forest plots displaying meta-analysis results for sensitivity (ie, the true positive rate) and specificity (ie, true negative rate) separately, and (b) Summary Receiver Operating Characteristic (SROC) curve to provide a global summary of test performance. Two primary shortcomings were identified: (a) lack of incorporation of quality assessment results into the main analysis and; (b) ambiguity with which the contribution of individual studies is represented on SROC curves. In response, two alternative graphical approaches were developed:

1. A quality assessment enhanced SROC plot which displays the results from individual studies in the meta-analysis with multiple indicators of quality assessed using QUADAS-2; and
2. A percentage study weights enhanced SROC plot which accurately portrays the percentage contribution each study makes to the meta-analysis.

The proposed enhanced SROC curves facilitate the exploration of DTA data, leading to a deeper understanding of the primary studies included in a DTA meta-analysis including identifying reasons for between study heterogeneity and why specific study results may be divergent. Both plots can easily be produced in the free online interactive application, MetaDTA (https://crsu.shinyapps.io/dta_ma/).