Table 2.

Key assumptions of NMA

Assumption
Similarity	Are the studies included in the NMA similar enough in terms of research question (PICOS) to be pooled together?
Transitivity	Are there any effect modifiers (patient or study characteristics) known or thought to influence the treatment effect? If so, are there no systematic differences in the distribution of effect modifiers between the included trials?
Consistency	For mixed comparisons, is there agreement between the direct (head-to-head) and indirect (via a common comparator) evidence within the network?
Homogeneity	Are there no imbalances in population, interventions, outcomes, or study design across direct and indirect comparisons within the NMA?

NMA network meta-analysis; PICOS population, intervention, comparator, outcome, setting