A systematic review attempts to collate 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 defined question with inclusion & exclusion criteria; rigorous & systematic search of the literature; critical appraisal of included studies; data extraction and management; analysis & interpretation of results; and report for publication. Systematic reviews should be carried out according to a predefined protocol that sets out the scope of the systematic review and details of the methodology to be used throughout the review.
Key components of a systematic review include:
Systematic reviews can evaluate a range of evidence; qualitative, quantitative or both. Appropriate methods of synthesis should be used for different types of evidence.
The systematic review process has been developed to minimize bias and ensure transparency. Methods should be adequately documented so that they can be replicated.
When conducted well, systematic reviews should give us the best possible estimate of any true effect. An assessment of the methodological quality of reviews should highlight the limitations of a review.
Understanding and interpreting research evidence is an important part of practicing evidence-informed public health. This short video from the National Collaborating Centre for Methods and Tools explains the types of reviews and what kind are needed.
Time: On average, systematic reviews require 18 months of preparation.
…to find out about a healthcare intervention it is worth searching research literature thoroughly to see if the answer is already known. This may require considerable work over many months…” (Cochrane Collaboration)
The suggested timeline for a Cochrane review is:
A team: A systematic review can't be done alone! You need to work with subject experts to clarify issues related to the topic; librarians to develop comprehensive search strategies and identify appropriate databases; reviewers to screen abstracts and read the full text; a statistician who can assist with data analysis; and a project leader to coordinate and write the final report.
A clearly defined question: Clarify the key question(s) of you systematic review and the rationale for each question. Use the PICO framework to identify key concepts of the question. Determine inclusion/exclusion criteria. Build a good clinical question to facilitate searching for a precise answer.
Structure of a clinical question:
A written protocol: You need to write a protocol outlining the study methodology. The protocol should include the rationale for the systematic review, key questions broken into PICO components, inclusion/exclusion criteria, literature searches for published/unpublished literature, data abstraction/data management, assessment of methodological quality of individual studies, data synthesis, and grading the evidence for each key question.
Official Protocol Resources:
A registered protocol: After you write the protocol, you should register it with PROSPERO, an International Prospective Register of Systematic Reviews. Registration is free and open to anyone undertaking systematic reviews of the effects of interventions and strategies to prevent, diagnose, treat, and monitor health conditions, for which there is a health related outcome.
Comprehensive literature searches: First, identify systematic reviews that may address your key questions. Then, identify appropriate databases and conduct comprehensive and detailed literature searches that can be documented and duplicated. Your research strategy has to be reproducible.
Citation management: You should have working knowledge of EndNote to help manage citations retrieved from literature searches.
Follow reporting guidelines: Use appropriate guidelines for reporting your review for publication.
For detailed literature information about the process: See Handbooks for Doing Systematic Reviews
These are the steps of a Systematic Review adapted from Cochrane Canada 2011, Session three: A 'snapshot' of the steps of conducting a Cochrane Review (part 1).:
Steps of a review (PIECES)
Library Liaisons can partner with you and advise on how to start a systematic review.
Basic Service includes:
Students needing help with systematic reviews can contact liaison librarians to learn about the process.
Systematic review service will be available to faculty, residents, fellows, and post-docs.
Full Services includes:
Make sure you review and complete the Systematic Review and Assessment forms before meeting with the Librarian:
Here is a powerpoint presentation that provides a brief overview of Systematic Reviews presented at the UTHealth School of Public Health on by Amy Taylor, Liaison Librarian at the Texas Medical Center Library