February 2025
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30 Reads
STANDFIRST This scoping review represents the initial step in updating the Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) extension for network meta-analysis (NMA) to improve the usability and relevance of systematic reviews with NMA for diverse audiences. The update will address gaps in reporting, such as documenting methods for assessing NMA homogeneity and transitivity, defining intervention nodes, and considering advances in statistical modeling. It will align with PRISMA 2020 and incorporate input from diverse knowledge users, including patients and the public. This scoping review included 61 studies, comprising 23 guidance documents and 38 overviews of reviews evaluating the completeness of reporting and methodological quality of published NMAs. We identified 37 additional NMA items for inclusion in the next step—the Delphi survey. Building on a 2014 scoping review by our team, we incorporated recent studies to inform the PRISMA-NMA update, adhering to established standards for guideline development. SUMMARY POINTS Network meta-analyses (NMAs) are increasingly prominent in evidence synthesis, but their methodological transparency and reporting completeness remain inconsistent, which affects the reliability of results. This scoping review highlights the need to update PRISMA-NMA to address evolving methodologies (e.g., component NMA) and reporting challenges to improve accessibility and utility of NMA findings. The review underscores progress and gaps in NMA reporting since the 2015 PRISMA-NMA extension, focusing on synthesis methods, homogeneity, consistency and transitivity assessments, and network geometry. Key recommendations, such as defining pre-specified nodes, specifying statistical methods, and addressing competing interests, were often overlooked in NMA reporting, but addressing these gaps could enhance transparency, reproducibility, and trust in NMA results.