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Systematic reviews and other evidence synthesis projects

What is a Systematic Review?

"A systematic review (SR) attempts to collate all empirical evidence that fits pre-specified eligibility criteria in order to answer a specific research question.  It uses explicit, systematic methods that are selected with a view to minimizing bias, thus providing more reliable findings from which conclusions can be drawn and decisions made.

Key characteristics of a systematic review are:

  • a clearly defined topic, with pre-defined eligibility criteria for studies
  • a systematic and reproducible search strategy
  • a critical appraisal of included studies
  • data extraction and processing
  • analysis and interpretation of results"

Higgins, Julian. Cochrane Handbook for Systematic Reviews of Interventions. Hoboken, NJ, USA: John Wiley & Sons, 2009. https://training.cochrane.org/handbook/archive/v5.0.2/.

Note: The full systematic review methodology is outside the scope of almost all class assignments or dissertation/thesis. If you are considering assigning one, please meet with a librarian about a modified version that will fit your course's needs and limits.

Steps in Producing a Systematic Review

  1. Define the question

  2. Check for recent systematic reviews and protocols

  3. Create a review protocol, and register it if appropriate

  4. Design and conduct reproducible, comprehensive searches

  5. Organize and screen search results

  6. Appraise the quality of the studies

  7. Extract data

  8. Analyze / synthesize data

  9. Write the review

Recommended viewing:

For a more thorough introduction, consider this free, asynchronous training course on conducting systematic reviews and meta-analyses from Johns Hopkins University through Coursera. (~13 hours)

Guides for Conducting Systematic Reviews

Multiple guidelines and standards exist to aid researchers in the creation of high quality systematic reviews and other evidence syntheses.

Reviews may be conducted in accordance to specific internationally-established guidelines, such as Cochrane, the Joanna Briggs Institute, the Campbell Collaboration, and the Collaboration for Environmental Evidence. These follow the most rigorous standards for planning and executing this type of research. Even if you are not conducting a review for one of these organizations, you may still find it valuable to review their guidance documents.Many of these guidelines have additional guidance on specific review content, such as Cochrane's section on systematic reviews on patient-reported outcomes or JBI's section on systematic reviews of qualitative evidence.

  • Cochrane Collaboration Handbook
    Official document that describes in detail the process of preparing and maintaining Cochrane systematic reviews on the effects of healthcare interventions.
  • JBI Manual for Evidence Synthesis
    Official document that describes in detail the process of preparing a JBI systematic or scoping review. Includes instructions for reviews focusing on different types of evidence, such as effectiveness, prevalence, and qualitative evidence. 
  • Campbell Collaboration
    Systematic reviews of research evidence on the effectiveness of social programs, policies, and practices, including crime and justice, education, international development, and social welfare.
  • AMSTAR checklist
    The AMSTAR checklist can be used to evaluate the methodological quality of an extant systematic review or as a guide when creating a systematic review. Short for "A MeaSurement Tool to Assess systematic Reviews."
  • AHRQ Methods Guide for Comparative Effectiveness Research (CER)
    AHRQ definitions and descriptions of methods for systematic reviews of CER
    "For an SR to meet the definition of CER, it should compare at least two alternative interventions, treatments, or systems of care (IOM, 2009b). The interventions and comparators should enable patients and clinicians to balance the benefits and harms of potential treatment options."

 

Reviews may also adhere to reporting standards, such as PRISMA or MOOSE. These can be useful tools for planning your review, too, used alongside (but not instead of!) guidelines.
The checklists below help you plan what steps you will need to do, you follow guidelines that describe how to do those steps, and the reporting standards help you rigorously and transparently report your process when writing your review.