Assessment of Risk of Bias in Randomized Trials Using RoB 2: Reflections From a Systematic Review of Complex Interventions.

The Cochrane risk-of-bias tool (RoB 2) is used to assess the risk of bias in randomized trials in systematic reviews. However, studies have shown that the tool is often incorrectly used and published reviews rarely include detail regarding how it was applied or offer reflections on using it. This paper is a transparent applied case example with lessons learned and limitations of using RoB 2 in a (non-Cochrane) systematic review evaluating the effectiveness of remote therapies for alcohol and drug use disorders. We share our reflections on aspects to plan in advance (pre-selecting the outcome(s) and their results and piloting the tool); factors to consider when applying the tool (multiple outcomes within a study and navigating resources); overcoming common problems within specific domains (developing a review-specific guidance document). Through our worked example, this article illustrates how review teams can engage with the RoB 2 tool within a specific review context to enhance its correct application.