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Library: Systematic Reviews

Essential Elements of Systematic Reviews

A systematic review uses systematic and reproducible methods to identify, select and critically appraise all empirical evidence that fits pre-specified eligibility criteria in order to answer a specific research question.  

The key characteristics of a systematic review are:

  • a clearly stated set of objectives with pre-defined eligibility criteria for studies;

  • an explicit, reproducible methodology;

  • a systematic search that attempts to identify all studies that would meet the eligibility criteria;

  • an assessment of the validity of the findings of the included studies, for example through the assessment of risk of bias; and

  • a systematic presentation, and synthesis, of the characteristics and findings of the included studies.

Higgins JPT, Green S (editors). Cochrane Handbook for Systematic Reviews of Interventions Version 5.1.0 [updated March 2011]. The Cochrane Collaboration, 2011. Available from

Difference between a Systematic Review and a Literature Review

Systematic Review Literature Review
Focused on a single question Not necessarily focused on single question - may describe an overview
A peer review protocol or plan is included No protocol is included
Clear objectives identified Objectives may or may not be identified
Inclusion/exclusion criteria stated before review is conducted Criteria not specified
Comprehensive search conducted and documented systematically Search strategy not explicitly stated
Process of article selection clear and explicit Process of article selection is not described
Formally assesses the quality of studies and generates a conclusion relating to the focused research question Summary based on studies where the quality may not be specified and may also be influenced by reviewer's theories, needs and beliefs

Adapted from: University of Newcastle Library

Conducting Systematic Reviews : Research Skills

Systematic reviews play an important role in health research. They provide a high level summary of studies and can inform policy and practice relevant to a particular area of inquiry. Understanding review methodologies is useful for those who wish to undertake a systematic review, or just read one.

Conducting Systematic Reviews video

Documenting the Search

Start documenting the search process from day one and continue to the end.

Create an account with the databases that you search and save your searches.

You will need to keep track of:

  • Databases searched, including database provider/platform (eg. OVID Medline, PsycINFO, Emcare)
  • Date search was conducted
  • Search strategy: subject headings and keywords used, including whether terms were exploded, truncated and how terms were combined
    TIP!  Copy and past the search exactly as run and include numbers of records retrieved
  • Years searched
  • Filters used
  • Number of results retrieved for each search
  • Total number of records 
  • Duplicates identified
  • Numbers pre-screening and post-screening

In addition, all searches conducted via hand searching must identify the source (name of journal, conference proceedings etc.) and the year.