Risk of Bias in Network Meta-Analysis (RoB NMA) tool
Systematic reviews with network meta-analysis (NMA) have potential biases in their conduct, analysis, and interpretation. If the results or conclusions of an NMA are integrated into policy or practice without any consideration of risks of bias, decisions could unknowingly be based on incorrect results, which could translate to poor patient outcomes. The RoB NMA (Risk of Bias in Network Meta-Analysis) tool answers a clearly defined need for a rigorously developed tool to assess risk of bias in NMAs of healthcare interventions. In this guidance article, we describe and provide a justification for the tool’s 17 items, their mechanism of bias, pertinent examples, and how to assess an NMA based on each response option. A network meta-analysis (NMA) is a type of quantitative analysis that can be performed as part of a systematic review.1234 An NMA is an extension of a pairwise meta-analysis that compares the effects of multiple interventions simultaneously on one clinical, public health, or
