Objectives: To provide the reviewer with a background to the problem of outcome reporting bias (ORB) and how it might lead to misleading conclusions, to demonstrate how a reviewer might identify such bias in their review, and to present techniques for assessing the robustness of the meta-analysis to such bias.
Description: There is a wealth of empirical evidence for the existence of ORB in both benefit and harm outcomes. Methods for the identification of ORB in a meta-analysis and an individual study will be described and illustrated using examples. The workshop will also describe two sensitivity approaches to adjust pooled effect estimates in the presence of ORB; multivariate meta-analysis [1] and a modelling approach [2]. Participants will be encouraged to undertake such assessments for examples provided and will be provided with the opportunity to apply the adjustment approaches.

[1] Kirkham JJ, Riley RD, Williamson PR. A multivariate meta-analysis solution for reducing the impact of outcome reporting bias in systematic reviews. Statistics in Medicine 201);31(20):2179-95.
[2] Copas J, Dwan KM, Kirkham JJ, Williamson PR. A model-based correction for outcome reporting bias in meta-analysis. Biostatistics 2014;15(2):370-83.