Introduction to network meta-analysis for evidence synthesis

Abstract

This article belongs to a collaborative methodological series of narrative reviews about biostatistics and clinical epidemiology. The goal is to present basics concepts concerning the systematics reviews of multiple treatments comparisons with network meta-analysis. For clinical ques-tions with several therapeutic alternatives to be compared, the central question is how to classify or rank their effectiveness (benefit and harm) to choose the best option. The network meta-analysis aims to answer questions related to the effectiveness and safety of comparing multiple treatments by the simultaneous analysis of results raised from direct and indirect comparisons. The network geometry is the general graphical representation of the network meta-analysis and allows to understand and assess the strength of comparisons. The network meta-analysis should check several assumptions to be valid, especially the transitivity assumption, which allows assuming that there are no systematic differences among the included comparisons, except their compared interventions. Thus, it is possible to know the relative therapeutic effectiveness of each pair of interventions included in the network meta-analysis and their ranking in terms of categorization. It has been proposed to use a modified Grading of Recommendation, Assessment, Development, and Evaluation (GRADE) approach considering the distinctive features of network meta-analysis to assess the certainty of the evidence for each comparison and the ranking of interventions.

Description of massage interventions in randomised clinical trials for neck pain; a review using the TIDieR checklist

“…19 Other reviews have also noted that, when using the TIDieR checklist, reporting of conservative interventions is at best moderate and did not improve over time. 24,27,36,[72][73][74] Our scores were comparable to other recent reviews regarding most checklist items. [23][24][25]72 One review reported a low score (55% of studies) on the description of the rationale, theory, or goal of manipulations and mobilisations, 23 while we found that 86% of the studies described a clear rationale for using massage (often relaxation purposes).…”

Systematic reviews: Key concepts for health professionals

“…Es importante señalar que existen otras formas de síntesis sistemática de evidencia, que se abordan con más detalle en otras notas metodológicas de Medwave [6]. Entre ellas se encuentran las revisiones panorámicas y mapeos de evidencia [15], las revisiones rápidas [16], las revisiones vivas (de actualización continua) [17], los metanálisis en red [18] y las revisiones de revisiones sistemáticas (u overviews).…”

“…Existe un abordaje adicional llamado metanálisis en red (network meta-analysis), cuya metodología permite el uso de evidencia de comparaciones directas e indirectas. El detalle de este tipo de estudio está descrito en detalle en otro artículo de esta serie metodológica [18].…”

A guide to appropriately planning and conducting meta-analyses: part 3. Special considerations—the network meta-analysis

“…Underlying the foundation of all network meta‐analyses is the assumption that transitivity is held true for every included indirect comparison [14]. Moreover, coherence must be maintained within all comparisons in the network [4]. Finally, heterogeneity among the direct comparisons should also be minimal in accordance with prior recommendations for traditional meta‐analyses as outlined in part 2 of this series.…”