Drug Evaluation Committee Introduction to the NICE TSD Evidence Synthesis Series: Focusing on Network Meta-Analysis
December 2020
In April 2019, a cost-effectiveness evaluation system was institutionalized to complement the existing drug pricing system.Under this new framework, when conducting a cost-effectiveness analysis, it is necessary to assess, through a systematic review, whether the technology under evaluation offers additional benefits compared to the comparator technology. However, in the case of new medical technologies (such as new drugs), there is often insufficient evidence available for direct comparison with a comparator technology in cost-effectiveness evaluations, making indirect comparisons necessary in some cases.In such cases, simple indirect comparisons are not recommended, and the use of adjusted indirect comparisons is required. Therefore, when indirect comparisons involving three or more groups are necessary, it is permissible to consider a method called network meta-analysis (NMA), which allows for the comprehensive utilization of trials that do not include the technology under evaluation or its comparator.Since NMA comprehensively utilizes evidence and can adjust for confounding factors present across trials, it is expected to reduce bias and improve the accuracy of estimates compared to simple indirect comparisons.
On the other hand, since NMA has certain assumptions that must be met to ensure the validity of its results, there are numerous points to keep in mind when using it. Therefore, an understanding of its methodology and an assessment of the validity of the NMA model (examination of heterogeneity and inconsistency) are essential, and careful interpretation of the results is crucial.
Since there are extremely few practical resources in Japan regarding NMAs for cost-effectiveness evaluations, the FY2019 DS Subcommittee Continuing Project T5 summarized the methodology and considerations for evidence synthesis centered on NMAs based on the Evidence Synthesis series (TSD1–7) of the Technical Support Documents (TSD) Evidence Synthesis series (TSD1–7) issued by the UK’s NICE, summarizing the methodology and key considerations for evidence synthesis centered on NMAs, and prepared a report that included Explanations incorporating the WinBUGS user guides and analysis examples found in the appendices of each TSD.
Please note that any references to or citations of the individual TSDs in this report represent the interpretations of this task force, and NICE bears no responsibility whatsoever.Furthermore, not all TSDs are presented here; only selected excerpts are included. In presenting these excerpts, the Task Force has added its own interpretations and supplementary explanations. Please note that these are the Task Force’s independent findings and do not represent the views of NICE.
Japan Pharmaceutical Manufacturers Association, Drug Evaluation Committee, Data Science Subcommittee
FY2019 Continuing Task Force 5