Umbrella Reviews: Concepts, Methodological Frameworks, and Step-by-Step Implementation.

The exponential growth of secondary literature has created an imperative for researchers to identify credible and methodologically sound studies within an increasingly complex information landscape. In light of the growing emphasis on evidence-based medicine in both domestic and international contexts, umbrella reviews (URs) have emerged as a critical methodological approach in biomedical research. As an advanced form of tertiary evidence synthesis, URs systematically integrate findings from multiple systematic reviews and meta-analyses, thereby providing a comprehensive evidence base for specific research questions or related fields. This methodological framework enhances the quality of evidence through critically evaluating the validity and reliability of conclusions drawn from secondary or primary studies. The present overview systematically examines the conceptual framework, distinctive characteristics, development process, and methodological quality assessment of URs, with the objective of establishing a theoretical foundation and practical reference for future research in this domain.