Indirect and mixed‐treatment comparison, network, or multiple‐treatments meta‐analysis: many names, many benefits, many concerns for the next generation evidence synthesis tool

Abstract

The ever increasing number of alternative treatment options and the plethora of clinical trials have put systematic reviews and meta-analysis under a new perspective by emphasizing the need to make inferences about competing treatments for the same condition. The statistical component in reviews that compare multiple interventions, network meta-analysis, is the next generation evidence synthesis toolkit which, when properly applied, can serve decision-making better than the established pairwise meta-analysis. The criticism and enthusiasm for network meta-analysis echo those that greeted the advent of simple meta-analysis. The main criticism is associated with the difficulty in evaluating the assumption underlying the statistical synthesis of direct and indirect evidence. In the present article, the assumption of the network meta-analysis are presented using various formulations, the statistical and nonstatistical methodological considerations are elucidated, and the progress achieved in this field is summarized. Throughout, focus is put on highlighting the analogy between the concerns and difficulties that the scientific community had some time ago when advancing from individual trials to their quantitative synthesis via meta-analysis and those currently expressed about the transition from head-to-head meta-analyses to network meta-analysis. Copyright © 2012 John Wiley & Sons, Ltd.

Bibliographic study showed improving statistical methodology of network meta-analyses published between 1999 and 2015

“…The PRISMA statement was published only recently and we do not expect it to have had any major impact on the improvements in reporting observed in our study. The educational papers published several years ago [12,27,28,56,57] might, however, have had some impact. Alternatively, improvements in NMA methods might be due to statisticians and clinicians becoming more experienced with NMA techniques.…”

“…Suggestions of accompanied detailed protocols on which authors should base their NMA reviews [12,27] have started to be applied. Among other merits, establishment of NMA protocol registration could substantially improve reporting and evaluation of transitivity through the a priori description of approaches that will be used to assess it.…”

“…In recent years, the methodology of NMA has been further refined and many tutorials and guidance papers have been published [12,[27][28][29][30][31]. Efthimiou inconsistency [33,34].…”

“…We recorded whether and how the authors evaluated the plausibility of transitivity (the comparability of the distribution of effect modifiers across treatment comparisons) prior to the data synthesis [27]. For networks including at least one closed loop, we also recorded the use of any statistical method to evaluate consistency (e.g.…”

A strengthening evidence-base for mass deworming, but questions remain

“…We should aim for minimum monetary and human cost involved and efficient future research planning. The use of network metanalysis [9] -a methodological tool which can include many competing treatments and make use of a wider evidence space by including direct and indirect comparisons could be a promising vehicle to answer some of these key questions.…”