Systematic Reviews: Writing the Review

šFollow one of the high-quality guides such as PRISMA, Cochrane, or MOOSE. The PRISMA 27-item checklist is an excellent and easy to use set of guidelines for the writing process. MOOSE is particularly useful if your review consists primarily of observations studies such as cohorts and case-controls. š

Basic Review Structure (Note: Read the selected journal's author instructions)

• Title
• Abstract
• Introduction (Rationale and clearly-stated PICO question)
• Methods
  • Search Protocol: databases searched, search terms used, date of searching, sample search strategy for at least 1 database. (Full search protocol may be included as supplementary material or made available upon reader request, depending on journal requirements.)
  • Inclusion/Exclusion criteria
  • Study Selection Process
  • Additional Searching (Grey Lit, handsearching, snowballing, etc.)
  • Data Collection and Evaluation Methods
  • Primary Outcome Measures
  • Address potential causes of bias in the review, often publication bias (for example, explain any search limitations such as dates, language, geographical region, etc.). There are tools that can be used to estimate and present publication bias.
  • Methods of synthesis of results (i.e. any statistics used, esp. for a meta-analysis)
• Results
  • Flow Diagram of the Study Selection Process with numbers (see example)
  • Number of selected studies/item
  • Discuss results of individual studies and comparisons
  • Summary Tables of Findings/Synthesis of results (see example)
  • Statistics and results of meta-analysis if done (see example)
  • Any additional analysis such as subgroup analyses
  • Report Risk of Bias in Included Studies (See Box on Bias on this Page)
  • Primary conclusions
• Discussion
  • Summary of key findings and their impact and implications
  • Limitations
    • Include any conflict of interest and funding sources, both for your review and for the included studies.
• Conclusion

From: Blackwood B, Alderdice F, Burns K, Cardwell C, Lavery G, O'Halloran P. Use of weaning protocols for reducing duration of mechanical ventilation in critically ill adult patients: Cochrane systematic review and meta-analysis. BMJ. 2011 Jan 13;342:c7237. PMID: 21233157; PMCID: PMC3020589.

Schnuriger, Beat; Inaba, Kenji; Konstantinidis, Agathoklis; Lustenberger, Thomas; Chan, Linda; Demetriades, Demetrios. Outcomes of Proximal Versus Distal Splenic Artery Embolization After Trauma: A Systematic Review and Meta-Analysis. Journal of Trauma-Injury Infection & Critical Care. 70(1):252-260, January 2011. DOI: 10.1097/TA.0b013e3181f2a92e

šPRISMA = Preferred Reporting Items for Systematic Reviews and Meta-Analyses

The PRISMA statement is the result of an international collaboration to promote quality and transparency in reporting systematic review research. It replaces the older QUORUM and is the ‘gold standard’ for reporting systematic reviews and meta-analyses.

šIt was published simultaneously in the BMJ, Annals of Internal Medicine, Journal of Clinical Epidemiology, and PLoS Medicine in 2009. An update was published in 2015 as PRISMA-P.

The PRISMA website 

• Download the full-text of the PRISMA Statement.
• Download the PRISMA 27-item checklist as PDF or MSWord Doc. 
• Download a template of the PRISMA Flow Diagram as PDF or MSWord Doc.

Please note that the published PRISMA checklists contain an error in the wording for Item 21. The item should read: "Present the main results of the review. If meta-analyses are done, include for each, confidence intervals and measures of consistency" in accordance with the text in the Explanation and Elaboration document.

The Cochrane Collaborationš is an internationally-recognized leader in creating high-quality systematic reviews and advancing Evidence-Based Medicine.

SBU has access to the searchable Cochrane Library which includes all of the Systematic Reviews, the Central Registry of Controlled Trials, Protocols for Reviews in Process, DARE (Other Reviews), Method Studies, Technology Assesssments, and Economic Evaluations.

The most valuable resource for conducting and writing systematic reviews is the free, online Cochrane Handbook for Systematic Reviews of Interventions. Cochrane also provides resources on reviews of diagnostic studies. A Handbook for Systematic Reviews of Diagnostic Studies is being created.

The Cochrane Collaboration provides an assessment tool for risk of bias.

See Higgins, 2008 for a discussion of the development of the assessment tool.

See The Cochrane Handbook for Interventional Studies, Chapter 8, for detailed instructions.

An example of a "Risk of bias graph" figure:

An Example of a "Risk of bias summary" Figure: