Meta analysis of diagnostic and prognostic studies Seminar

Abstract
In this talk I will discuss some of my recent research on meta-analysis for diagnostic and prognostic studies. In the first part, I will consider the issue of multiple thresholds. When meta-analysing diagnostic test accuracy studies, each study may provide results for one or more thresholds; however, the thresholds reported by each study often differ. In this situation researchers typically meta-analyse each threshold independently. Here, I rather consider jointly synthesising the multiple thresholds to gain more information. Two approaches are examined: a multivariate meta-analysis model and a linear imputation method. Both these can be followed by a meta-regression that constrains sensitivity/specificity estimates to decrease/increase as threshold value increases, thereby producing a clinically interpretable summary ROC curve. In the second part, I present a review of individual patient data (IPD) meta-analyses of prognostic factor studies, and evaluate how they are conducted and reported. IPD has long been considered the 'gold-standard' approach to meta-analysis, but I will show that it does not solve all the problems and much work is needed in the IPD field.