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Advanced Literature Search Guide for Nursing and Health Sciences: Systematic reviews

Systematic reviews guide

This page explains what a systematic review is and provides further resources to help you carry out this type of review. 

Literature (narrative) reviews

Traditional literature reviews are those where researchers have sought to organise existing knowledge and publish summary of a variety of topics. They are useful for background reading and gathering information on a specific topic.

  • They are rigorous than a SLR and conducted by one researcher.
  • Based on one or more databases.
  • Uses appropriate terms with synonyms, related terms etc.
  • Include an audit trail (usually presented in a table) showing how you arrived at your final articles.

The evidence hierarchy

Top of hierarchy

Secondary research (pre-appraised and synthesized)

  • Evidence based guidelines
  • Systematic reviews (syntheses of existing studies)


Primary research(original first hand research)

  • Single large group study e.g. Randomised Controlled Trials (RCTs)
  • Other groups studies e.g. observation studies
  • Case study or report
  • Background information or expert opinion
Bottom of hierarchy

Systematic reviews

A systematic review is a review of a clearly formulated question that uses systematic and explicit methods to identify, select and critically appraise relevant research and to collect and analyse data from the studies that are included in the review (Cochrane Handbook, 2011).Often conducted by a team rather than a single researcher, it is not merely a descriptive summary of the studies you have chosen but should aim to do the following:

  • Focus on a single topic with strict criteria parameters and consistent methodology.
  • Cover all the available research relating to the question.
  • Draw the evidence together and start to relate the studies together.
  • Combine findings across the studies and look for themes and patterns, similarities and overlaps and differences between the studies.
  • Draw together different study perspectives and recommendations for practice.
  • Acknowledge the study limitations as presented by the authors themselves or, alternatively, include an assessment of the strengths and weaknesses of the studies.
  • Examine, compare and summarise each piece of research identified.
  • Aim for a considered judgement and a balanced and unbiased conclusion.

More about systematic reviews

Below are some links to further information about systematic reviews.

Conducting a systematic review

Further information about how to carry out a systematic review. 

All images included in this guide are available from Upsplash through Creative Commons licensing CC-BY-2.0