Welcome!

On these pages, you can find the latest version of the "RoB 2 specifications for the use in psychotherapy trials" extended manual", which is the basis of the Metapsy risk of bias tool.

Preliminary considerations

The specifications explained in this document should not be considered as a substitution of the Cochrane’s RoB 2 tool manual. Rather, the guidance provided in this document attempts to provide further recommendations when using the RoB 2 tool in the context of psychotherapy trials.

Guidance for each of the five domains of the RoB 2 tool is operationalized in 24 items that assist the application of the RoB 2 signaling questions in the context of psychological interventions. All items are formulated in the same direction, in which “Yes/PY” answers are indicative of lower risk of bias.

The current recommendations of this extended manual are applicable for individually randomized parallel-group trials. Some of the core specifications from this extension can be applied for cluster randomized trials or crossover trials, however, these types of designs pose specific challenges that should be further evaluated. Cochrane’s RoB 2 tool includes specific versions of the tool for these types of designs.

As recommended by the RoB 2 tool, assessment of risk of bias should be specific to a particular result (e.g., standardized mean difference between psychotherapy and control condition) for a particular outcome (e.g., depression severity) and measured at a particular time (e.g., post-test), although some biases may apply to the whole study.

The recommendations of these documents are aimed at examining the effect of assignment to intervention, given that this is the type of assessment of primary choice by clinical guideline developers and policy makers. However, if reviewers wish to assess the effect of adhering to intervention, the RoB 2 tool contains a section specific to that aim.

"createRobRatings"

Variables marked with the tag createRobRatings↗ do not need to be answered manually by the reviewers if there is a Metapsy formatted dataset that has already collected required variables for these items: rating, attrition in each arm, and randomization ratio.

PDF Version

A PDF version of this handbook can be found here.