The use of network meta-analysis in updating WHO living maternal and perinatal health recommendations.

Drawing on two recent examples of WHO living guidelines in maternal and perinatal health, this paper elucidates a pragmatic, stepwise approach to using network meta-analysis (NMA) in guideline development in the presence of multiple treatment options. NMA has important advantages. These include the ability to compare multiple interventions in a single coherent analysis, provide direct estimates of the relative effects of all available interventions, infer indirect effect estimates for interventions not directly compared and generate rankings of the available treatment options. It can be difficult to harness these advantages in the face of a lack of current guidance on using NMA evidence in guideline development, with several challenges emerging. Challenges include the choice of conceptual approach, the volume and complexity of the evidence, the contribution of treatment rankings, and the fact that the preferable treatment is not always obvious. This paper describes a layered approach to resolving these challenges, which supports systematic guideline decision-making and development of trustworthy clinical guidelines when multiple treatment options are available.