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Semin Liver Dis 2018; 38(02): 103-111
DOI: 10.1055/s-0038-1655776
Review Article
Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

A Primer on Systematic Reviews and Meta-Analyses

Nghia H. Nguyen
1   Department of Internal Medicine, University of California San Diego, La Jolla, California
,
Siddharth Singh
2   Division of Gastroenterology, University of California San Diego, La Jolla, California
3   Division of Biomedical Informatics, University of California San Diego, La Jolla, California
› Author Affiliations
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Publication History

Publication Date:
05 June 2018 (online)

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Abstract

With the rapid growth of biomedical literature, there is increasing need to make meaningful inferences from a comprehensive and complex body of evidence. Systematic reviews with or without meta-analyses offer an objective and summative approach to synthesize knowledge and critically appraise evidence to inform clinical practice. Systematic reviews also help identify key knowledge gaps for future investigation. In this review, the authors provide a step-by-step approach to conducting a systematic review. These include: (1) formulating a focused and clinically-relevant question; (2) designing a detailed review protocol with explicit inclusion and exclusion criteria; (3) performing a systematic literature search of multiple databases and unpublished data, in consultation with a medical librarian, to identify relevant studies; (4) meticulous data abstraction by at least two sets of investigators independently; (5) assessing risk of bias in individual studies; (6) quantitative synthesis with meta-analysis; and (7) critically and transparently ascertaining quality of evidence.

Keywords

knowledge synthesis - evidence-based medicine - pooled analysis

Disclosures

Dr. Singh is supported by the American College of Gastroenterology and Crohn's and Colitis Foundation, and has received research grants from Pfizer and AbbVie. Dr. Nguyen does not have any relevant financial disclosures.


 

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