手法を比較

	ナラティブレビュー	Umbrella Review
分野	科学計量学	エビデンス統合
系統	Process / pipeline	Process / pipeline
提唱年	Pre-20th century practice; peer-reviewed methodological guidance from 2000s onward	2009
提唱者	Traditional academic practice; formalized discussion by Green, Johnson & Adams (2006)	Grant & Booth (2009), Refined by AMSTAR-2 (Shea et al., 2017)
種類	Literature review methodology	Framework
原典	Green, B. N., Johnson, C. D., & Adams, A. (2006). Writing narrative literature reviews for peer-reviewed journals: secrets of the trade. Journal of Chiropractic Medicine, 5(3), 101–117.	Grant, M. J., & Booth, A. (2009). A typology of reviews: An analysis of 14 review types and associated methodologies. Health Information & Libraries Journal, 26(2), 91–108.
別名	traditional review, expert review, unsystematic review, narrative synthesis	Overview of Reviews, Meta-Review, Review of Reviews
関連	6	2
概要	A narrative review is a broad, author-directed synthesis of published literature on a topic, written to summarize, interpret, and contextualize existing knowledge without following the rigorous, pre-registered search and selection protocols that characterize systematic reviews. It draws on the author's expertise to weave disparate sources into a coherent account that identifies themes, debates, and directions for future research.	An umbrella review is a systematic synthesis of multiple systematic reviews addressing overlapping or related research questions, typically on the same topic or intervention. Also called a 'review of reviews' or 'overview of reviews,' umbrella reviews consolidate evidence when two or more high-quality systematic reviews exist on the same clinical question. Grant and Booth (2009) formally categorized this methodology; Shea et al. (2017) developed AMSTAR-2, the critical appraisal tool for assessing the quality of included reviews. Umbrella reviews are essential when numerous systematic reviews produce conflicting conclusions, when rapid synthesis of evidence is needed for policy or clinical guidance, or when evidence has accumulated faster than any single systematic review can capture.