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Systematic Reviews

An overview of the Systematic Review process.

Definition of a systematic review

High quality systematic reviews aim to:

  • Identify all relevant published and unpublished evidence on the subject of the review
  • Select studies for inclusion
  • Assess the quality of each study
  • Synthesis the findings in an unbiased way
  • Present a balanced summary of the findings

(University of York, 10 tips for Systematic Reviews)

Further information

Cochrane Handbook for Systematic Reviews of Intervention - the official guide that describes in detail the process of preparing and maintaining Cochrane systematic reviews on the effects of healthcare interventions.

University of York Library: 10 tips for Systematic Reviews - useful guide to undertaking systematic reviews.

The difference between a Systematic Review and a Literature Review - pictorial illustration of the main differences between systematic reviews and literature reviews (Kysh, L., University of Southern California).

Example search strategy using the PICO framework

Using alternative keywords in PICO framework

combining alternative keywords with or in PICO framework, patient and intervention

combining alternative keywords with or in PICO framework, comparison and outcome

combining concepts with and in PICO framework

combining concepts with and in PICO framework

Getting started: The eight stages of a systematic review

  • Defining the review question and developing criteria for including studies

  • Searching for studies

  • Selecting studies and collecting data

  • Assessing risk of bias in included studies

  • Analysing data and undertaking meta-analyses

  • Addressing reporting biases

  • Presenting results and 'Summary of findings' tables

  • Interpreting results and drawing conclusions
    Cochrane Handbook for Systematic Reviews of Intervention

This guide will provide guidance on the first three stages of the process.

Documenting your search

Systematic reviews necessitate the provision of an accurate account of the processes undertaken to find evidence. Give details of:

  • Databases searched with dates
  • Keywords and subject headings used
  • Other methods used.

PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) statement:

Critical appraisal of systematic reviews

A range of checklists exist to help you in the process of assessing the quality and relevance of a systematic review (as well as other study designs).  These include:

Finding existing/proposed systematic reviews