Skip to main content

Systematic Reviews & Other Review Types

This guide will help you get started with your next systematic review, Scoping Review, or other review types.

Other names for a Network Meta-Analysis

NMA, MTC Meta-Analysis, Multiple Treatment Meta-Analysis, Mixed Treatments Comparison, Multiple Treatments Comparison, Pair-Wise Meta-Analysis, Indirect Treatment Comparison, Multiple Treatment Comparison Meta-Analysis, Live Cumulative Network Analysis (New type)

What is a Network Meta-Analysis?

"Network meta-analysis compares multiple interventions simultaneously by analyzing studies making different comparisons in the same analysis."

(Source: M. Petticrew et al (2013))

Network meta-analyses are best designed for:

  • Conditions with multiple interventions
  • Many combinations of direct or indirect interactions 
  • To answer more relevant clinical questions
  • To make treatment estimates for an entire treatment network instead of scanning each individual pair-wise comparison
  • To give the "full picture" to clinicians
  • Gain precision by considering all available evidence, not just (A vs. B comparisons)
  • Potential to more explicitly "rank" treatments using summary outputs

How a Network Meta-Analysis differs from a traditional Systematic Review

Timeframe: 12-18+ months.  Same as a traditional systematic review.  *Varies beyond the type of review. Depends on many factors such as but not limited to: resources available, the quantity and quality of the literature, and the expertise or experience of reviewers" (Grant et al. 2009)

Question: Addresses PICO for multiple interventions or treatments (3 or more).  These may be broad or narrow.  Combines indirect (triangular approach) or direct comparisons (pairwise approach). 

Sources and searches: Requires a large search to locate all of the trials using transparent & reproducible methods.

Selection: Same as a systematic review--based upon clear inclusion/exclusion criteria.  Requires a lot more screening of trials.

Appraisal: Formal quality assessment of all studies.  Still includes Risk of Bias and quality of evidence assessments.

Synthesis: Statistical analysis when possible (heterogeneity a potential problem with indirect comparisons)--uses different statistical methods than a systematic review. Creates a web-like analysis called a Network Diagram or Network Comparison.  May use bayesian frameworks or meta-regression analysis.

Example of a published Treatment Network for the Drugs Considered in the Example Multiple Treatment Comparison on Generalized Anxiety Disorder

Sample Network Comparison for a Network Meta-analysis

Source: 

  • Mills, Edward J., John P. A. Ioannidis, Kristian Thorlund, Holger J. Schünemann, Milo A. Puhan, and Gordon H. Guyatt. 2012. How to use an article reporting a multiple treatment comparison meta-analysis. Jama 308 (12): 1246-53.  http://jamanetwork.com/journals/jama/fullarticle/1362030

Resources:

Assessing the Feasibility of a Network Meta-Analysis (VIDEO) https://youtu.be/N-BlViss6AU

Petticrew M, Rehfuess E, Noyes J, et al.  Synthesizing evidence on complex interventions: how meta-analytical, qualitative, and mixed method approaches can contribute.  J Clin Epid. 2013;66:1230-1243.

Li T, Puhan MA, Swaroop SV, Dickersin K, et al.  Network meta-analysis-highly attractive but more methodological research is needed.  bmc medicine.  2011.  

Reporting Guidelines-PRISMA NMA for Network Meta-Analyses (Published in 2015)

http://www.prisma-statement.org/Extensions/NetworkMetaAnalysis.aspx

Cochrane Network Meta-analysis Toolkit http://methods.cochrane.org/cmi/network-meta-analysis-toolkit

Link to Published Network Meta-Analyses 

Graphical Tools for Network Meta-Analysis in STATA 

http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0076654

ISPOR Task Force on Indirect Comparisons and Network Meta-Analysis

https://www.ispor.org/workpaper/interpreting-indirect-treatment-comparison-and-network-meta-analysis-studies-for-decision-making.pdf​

What is a Live Cumulative (NMA) Network Meta-Analysis:

An NMA that is updated at regular intervals via crowdsourcing of a research community.

Resources:

http://livenetworkmetaanalysis.com

Créquit PTrinquart LRavaud P.  Live cumulative network meta-analysis: protocol for second-line treatments in advanced non-small-cell lung cancer with wild-type or unknown status for epidermal growth factor receptor.  http://bmjopen.bmj.com/content/6/8/e011841.full

Limitations of a Network Meta-Analysis

  • Requires specialist statistical expertise and software
  • Assumes that all interventions included in the "network" are equally applicable to all populations and contexts of the studies included.
  • May introduce study selection bias.
  • Ease of software may lead researchers to undertake this type of review even though it may not be the most appropriate study design for their research question.
  • Complex methodological approaches
  • Still an evolving method

(Source: M. Petticrew et al (2013) and Li T. et al (2011))

Library help

If you have any questions or need help, contact Stephanie Roth, stephanie.roth@temple.edu, 215-707-9469.

You can also use our Ask A Librarian options to get assistance. Ask a Librarian