Our concept
We propose to switch :
From a series of conventional meta-analysis focusing on specific treatments
to a single systematic review and evidence synthesis
through automatic updates.
We need a comprehensive, up-to-date synthesis of evidence for all treatments available for a given disease.
For many conditions, multiple competing treatments are available, many of which have been assessed in randomized trials. Clinicians and patients who are making medical decisions need to know which treatments work best among all treatments available for the condition of interest. They increasingly use meta-analyses that synthesize the results of randomized trials to inform the relative efficacy and safety of the different treatments. Conventional meta-analyses assess comparisons between only two treatments and thus focus on specific parts of the existing evidence.
An exhaustive synthesis could be provided by a network meta-analysis. This technique allows for comparing all treatments to each other, even if randomized controlled trials are not available for some treatment comparisons.
Research is wasted when meta-analyses fail to provide a complete and up-to-date evidence synthesis
In a specific condition, second-line treatments of advanced non-small-cell lung cancer, we have shown that, when considered collectively, the 29 meta-analyses published from 2001 to 2015 did not encompass the whole available randomized evidence. In fact, more than 40% of treatments, of treatment comparisons and of trials were missing.
Another potential concern is that few meta-analyses are updated while, according to the clinical area, a meta-analysis may become quickly out-of-date. In a sample of 100 meta-analyses, about a quarter was out of date within two years of publication .
Conventional meta-analyses do not provide an exhaustive up-to-date synthesis of all available treatments, and thus prevent from answering easily to the real questions of interest.
Methodological steps of living network meta-analysis
The figure shows the methodological steps for a living NMA. It is initiated with a NMA. Six methodological steps are then repeated at regular intervals to keep the NMA updated over time: adaptive search for treatments and trials, screening of reports and selection of trials, data extraction, assessment of risk of bias, update of the network of trials and evidence synthesis and lastly dissemination.
The iterations and the update frequency are designed to maintain the high-quality standards of the systematic review and to ensure that they are feasible.
An important aspect is the creation of a community of experts and its involvement at different steps of the process. Such a community will increase the clinical relevance, methodological validity and practical feasibility of the living NMA.
We call this approach “live cumulative network meta-analysis” or “living network meta-analysis” or “living NMA”
References
- Créquit P, Trinquart L, Yavchitz A, Ravaud P. Wasted research when systematic reviews fail to provide a complete and up-to-date evidence synthesis: the example of lung cancer. BMC Med. 2016 Jan 20;14(1):8. doi: 10.1186/s12916-016-0555-0. PubMed PMID: 26792360; PubMed Central PMCID: PMC4719540.
- Crequit P, Trinquart L, Ravaud 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. BMJ Open 2016;6(8):e011841.
- Créquit P, Martin-Montoya T, Attiche N, Trinquart L, Vivot A, Ravaud P. Living network meta-analysis was feasible when considering the pace of evidence
generation. J Clin Epidemiol. 2019 Apr;108:10-16. doi: 10.1016/j.jclinepi.2018.12.008. Epub 2018 Dec 12. PubMed PMID: 30552957.
