Σύγκριση μεθόδων

	Επισκόπηση Ομπρέλας Βάσει Πρωτοκόλλου	Επισκόπηση Ομπρέλας
Πεδίο	Επιστημομετρία	Σύνθεση Τεκμηρίων
Οικογένεια	Process / pipeline	Process / pipeline
Έτος προέλευσης	2011-2015 (PROSPERO launched 2011; JBI umbrella review guidelines 2015)	2009
Δημιουργός	Developed from umbrella review methodology; protocol registration practice formalized through PROSPERO (York) and JBI	Grant & Booth (2009), Refined by AMSTAR-2 (Shea et al., 2017)
Τύπος	Registered evidence synthesis review	Framework
Θεμελιώδης πηγή	Aromataris, E., Fernandez, R., Godfrey, C. M., Holly, C., Khalil, H., & Tungpunkom, P. (2015). Summarizing systematic reviews: methodological development, conduct and reporting of an umbrella review. JBI Evidence Implementation, 13(3), 132-140.	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.
Εναλλακτικές ονομασίες	pre-registered umbrella review, prospero-registered umbrella review, registered overview of reviews, protocol-driven umbrella review	Overview of Reviews, Meta-Review, Review of Reviews
Συναφείς	5	2
Σύνοψη	A protocol-based umbrella review is an umbrella review — a synthesis of existing systematic reviews and meta-analyses on a common topic — conducted under a publicly pre-registered protocol, typically in PROSPERO or a similar registry. Pre-registering the protocol before data collection begins commits the research team to prospectively defined eligibility criteria, search strategy, appraisal tools, and synthesis methods, sharply reducing the risk of outcome reporting bias and post-hoc analytical flexibility.	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.