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Systematic Reviews

Systematic reviewing

Introduction

Image courtesy: Centre for Health Communication and Participation La Trobe University, Australasian Cochrane Centre

This LibGuide is an introduction to the art and science of systematic reviewing.  According to Gopalakrishnan and Ganeshkumar (2013) - systematic review and meta-analysis are ways of summarizing the research evidence.  Not all disciplines use systematic reviews, but they are common in medicine, nursing, education, social care and social work.  The technique is also being developed in other fields such as geography, history, archaeology and theology.  Also systematic reviews may not be the best technique to use for your study.  

Given all of this and the usage in health and social care - this guide pertains in the main to health/social care related reviewing.

The information gathered through these processes can form the foundation for evidence based research, education and practice in a wide range of contexts.

The LibGuide is based on the guide (opens in new window) developed by Cambridge University Medical School Library and we thank them for their help in allowing us to use their guide as the basis for this one.

What is a systematic review?

Systematic reviews seek to collate evidence that fits pre-specified eligibility criteria in order to answer a specific research question. They aim to minimize bias by using explicit, systematic methods documented in advance with a protocol - Cochrane Handbook (link opens in new window).  The Campbell Collaboration (link opens in new window)  and EPPI-Centre (link opens in new window) also provide information and advice.

Types of review

There are many types of reviews (including systematic reviews), each having slightly different purposes and methodologies.

  • Rapid review: narrow, quick search and assessment of very specific question
  • Scoping review: assessment of potential size/scope of available literature
  • Integrative review: includes qualitative/quantitative/ theory
  • Umbrella review: review of systematic reviews

For details of other review types see:

Grant M, Booth A. A typology of reviews: an analysis of 14 review types and associated methodologies (link opens in new window). Health Information & Libraries Journal. 2009;26(2):91-108.

Systematic review stages

A systematic review consists of many separate stages.  Some of the keys stages are illustrated on the timeline below.

Systematic reviewing is a time consuming activity.  You can save a lot of time at the beginning of your review by ensuring you are asking the right questions and phrasing these correctly.  In turn this will save a lot of time later when you are developing the search and carrying out the screening process.

At every stage of the review it is good practice to document:

  • search strategies (including numbers of articles each term retrieves) 
  • inclusion and exclusion criteria when screening,
  • method used to critically appraise papers, and
  • how data was extracted and analysed.

All this documentation will be crucial when reaching the final stage which is writing up and submitting the systematic review for publication, assessment or any other context the review may be used for eg policy development..

Timescales

Please also be aware that undertaking a systematic review can take a significant amount of time.  One of the main players in the production of systematic reviews is the Cochrane Collaboration.  The term Collaboration is crucial here as no one could compile a complete systemic review on their own - it is too onerous a task.  If you are a student working on a review it is very likely that you will be undertaking a "slimmed down" version of a complete systematic review.

The table below (from an archived version of the Cochrane Handbook) illustrates the time elements involved 

Month                    Activity
1 - 2    Preparation of protocol
3 - 8    Searches for published and unpublished studies
2 - 3    Pilot test of eligibility criteria
3 - 8    Inclusion assessments
3    Pilot test 'Risk of bias' assessment
3 - 10    Validity assessments
3    Pilot test of data collection
3 - 10    Data collection
3 - 10    Data entry
5 - 11    Follow up of missing information
8 - 10    Analysis
10 - 11    Preparation of review report
12 -    Keeping the review up-to-date

Further Support

This LibGuide concentrates on the practicalities of retrieving the information forming the basis of the review.  There is a whole range of other support available to you via your institution and/or supervisor.  Remember to utilise this support as well.

Contact Us

For any assistance/advice required please contact the Library Team at: hhsl@uhi.ac.uk