These videos, originally part of the RoB 2: Learning Live webinar series, explain how to use the fourth domain of the RoB 2: bias in measurement of the outcome. The presenters discuss the signalling questions, including whether the method of measuring the outcome was inappropriate; if the measurement or ascertainment of the outcome could have differed between the intervention groups; whether outcome assessors were aware of the intervention received by study participants; if assessment of the outcome could have been influenced by knowledge of the intervention received and if it is likely that assessment of the outcome was influenced by knowledge of the intervention received. Finally, the presenters show the algorithm for how answers to signalling questions are mapped to judgements about risk of bias for the domains, along with worked examples..

This session was intended for people who are interested in using RoB 2 to assess risk of bias in their review. In addition to review author teams, CRG editors can learn about the risk of bias in measurement of the outcome so that they are able to assist authors with any queries they may have and also ensure information included in the review for this domain are relevant.

The webinar was delivered in September 2020 and below you will find the videos from the webinar, together with accompanying slides to download [PDF].

Part 1: Bias mechanisms and empirical evidence
Part 2: Assessing the risk of bias in measurement of the outcome: signalling questions 1-2
Part 3: Assessing the risk of bias in measurement of the outcome: signalling questions 3-5
Part 4: Questions and answers

Presenter Bios

Asbjørn Hrobjartsson is Professor of evidence based medicine and clinical research methodology in the University of Southern Denmark’s Department of Clinical Research and Head of research of Centre for Evidence-based Medicine Odence (CEBMO) at Odense University Hospital. He is co-convenor of the Cochrane Bias Methods Group, member of the Cochrane Scientific Committee and a former interim senior editor of the Cochrane Library. His research interests involves theoretical and empirical issues related to bias in clinical trials and systematic reviews, blinding, placebo, and conflicts of interests, as well as reporting guidelines and tools to address risk of bias.

Isabelle Boutron is professor of epidemiology at the Université de Paris, head of the Methods Team (INSERM- Epidemiology and Statistics Research Centre-CRESS). She is director of Cochrane France and co-convenor of the Cochrane Bias Methods Group and member of the SPRIT-CONSORT executive committee. Her research focusses on meta-research, methodological issues of assessing interventions (blinding, external validity, complex interventions), transparency, reporting guidelines development and implementation and research synthesis. She is also coordinating the MiRoR projects (http://miror-ejd.eu/) an innovative and ambitious joint doctoral training programme funded by Marie Skłodowska-Curie Actions, dedicated to Methods in Research on Research (MIROR) in the field of clinical research.

Part 1: Bias mechanisms and empirical evidence

Part 2: Assessing the risk of bias in measurement of the outcome: signalling questions 1-2

Part 3: Assessing the risk of bias in measurement of the outcome: signalling questions 3-5

Part 4: Questions and answers

Additional materials

Download the slides from the webinar [PDF]