Skip to Main Content

Systematic Review

Resources for conducting a systematic review research.

Steps of a Systematic Review

Walking fingers going up on a staircase made of books

Image by TraceyChandler

Steps to conducting a systematic review

Quick overview of the process:

Recommended readings:

Consult these manuals frequently at every step of your review:

Tools Steps

PICO template

1. Identify your research question. Formulate a clear, well-defined research question of appropriate scope. Define your terminology. Find existing reviews on your topic to inform the development of your research question, identify gaps, and confirm that you are not duplicating the efforts of previous reviews. Consider using a framework like PICO or SPIDER to define you question scope. Use Database Search Log Excel spreadsheet to record search terms under each concept. 

Optional: It is a good idea to register your protocol in a publicly accessible way. This will help avoid other people completing a review on your topic. Similarly, before you start doing a systematic review, it's worth checking the different registries that nobody else has already registered a protocol on the same topic.

  • Cochrane Collaboration - Systematic reviews of health care and clinical interventions
  • Campbell Collaboration - Systematic reviews of the effects of social interventions
  • COMRADES (Collaborative Approach to Meta-Analysis and Review of Animal Data from Experimental Studies)
  • F1000 Research - The protocol is published immediately and subjected to open peer review. When two reviewers approve it, the paper is sent to Medline, Embase and other databases for indexing.
  • Figshare - upload a protocol for your scoping review
  • JBI - Systematic reviews of healthcare practices to assist in the improvement of healthcare outcomes globally
  • Open Science Framework (OSF) Registries - Registry of a protocol on OSF creates a frozen, time-stamped record of the protocol, thus ensuring a level of transparency and accountability for the research. There are no limits to the types of protocols that can be hosted on OSF.
  • *** PROSPERO - International prospective register of systematic reviews. This is the primary database for registering systematic review protocols and searching for published protocols. Scoping reviews are not accepted. PROSPERO accepts protocols from all disciplines (e.g., psychology, nutrition) with the stipulation that they must include health-related outcomes. PROSPERO Protocol Template
  • Research Registry - Similar to PROSPERO. Based in the UK, fee-based service, quick turnaround time.
  • Research Square - Submit a pre-print, or a protocol for a scoping review. 
  • Zenodo - Share your search strategy and research protocol. No limit on the format, size, access restrictions or license.

Example outlining the details and documentation necessary for conducting a systematic review:

Hersi, M., Traversy, G., Thombs, B. D., Beck, A., Skidmore, B., Groulx, S., … Stevens, A. (2019). Effectiveness of stop smoking interventions among adults: protocol for an overview of systematic reviews and an updated systematic review. Systematic Reviews, 8(1), 28. https://doi.org/10.1186/s13643-018-0928-
Inclusion/exclusion criteria template  2. Define inclusion and exclusion criteria. Clearly state the criteria you will use to determine whether or not a study will be included in your search. Consider study populations, study design, intervention types, comparison groups, measured outcomes. Use some database-supplied limits such as language, dates, humans, female/male, age groups, and publication/study types (randomized controlled trials, etc.).
Database search log template 3. Search for studies. Run your searches in the databases that you've identified as relevant to your topic. Work with a librarian to help you design comprehensive search strategies across a variety of databases. Approach the grey literature methodically and purposefully. Collect ALL of the retrieved records from each search into a reference manager, such as Endnote, Zotero or Mendeley, and de-duplicate the library prior to screening. Report the searches using the PRISMA-S guidelines and CADTH Grey Matters.
Rayyan - export your Endnote results in this screening software 4. Select studies for inclusion based on pre-defined criteria. Start with a title/abstract screening to remove studies that are clearly not related to your topic. Use your inclusion/exclusion criteria to screen the full-text of studies. It is highly recommended that two independent reviewers screen all studies, resolving areas of disagreement by consensus.
Review matrix template 5. Extract data from included studies. Use a spreadsheet, or systematic review software (e.g. Rayyan, RevMan), to extract all relevant data from each included study. It is recommended that you pilot your data extraction tool, to determine if other fields should be included or existing fields clarified.
Risk of Bias (Quality) Assessment - Repository of tools (download the Excel spreadsheet to see all data) 6. Evaluate the risk of bias of included studies. Use a Risk of Bias tool (such as the Cochrane RoB Tool) to assess the potential biases of studies in regards to study design and other factors. Read the Cochrane training materials to learn about the topic of assessing risk of bias in included studies. You can adapt existing tools (PDF p.5) to best meet the needs of your review, depending on the types of studies included.

- PRISMA Flow Diagram

- PRISMA Checklist

Manuscript template

7. Present results and assess the quality of evidence. Clearly present your findings, including detailed methodology (such as search strategies used, selection criteria, etc.) such that your review can be easily updated in the future with new research findings. Perform a meta-analysis, if the studies allow. Provide recommendations for practice and policy-making if sufficient, high quality evidence exists, or future directions for research to fill existing gaps in knowledge or to strengthen the body of evidence.

For more information, see: 

  • Liumbruno, G. M., Velati, C., Pasqualetti, P., & Franchini, M. (2013). How to write a scientific manuscript for publication. Blood Transfusion, 11(2), 217–226. https://doi.org/10.2450/2012.0247-12 
  • Academic Phrasebank - Get some inspiration and find some terms and phrases for writing your manuscript
  • GradeProof - Automated high-quality spelling, grammar and rephrasing corrections using artificial intelligence (AI) to improve the flow of your writing. Free and subscription plans available.

Elsevier Journal Finder

Springer Journal Suggester

8. Find the best journal to publish your work. Identifying the best journal to submit your research to can be a difficult process. To help you make the choice of where to submit, simply insert your title and abstract in any of the journal finder tools listed under the Publishing your Systematic Review tab. 

Adapted from A Guide to Conducting Systematic Reviews: Steps in a Systematic Review by Cornell University Library

 

Diagram showing what authors do

This diagram illustrates in a visual way and in plain language what review authors actually do in the process of undertaking a systematic review.

Diagram showing the elements of a systematic review

This diagram illustrates what is actually in a published systematic review and gives examples from the relevant parts of a systematic review housed online on The Cochrane Library. It will help you to read or navigate a systematic review.

Source: Cochrane Consumers and Communications (infographics are free to use and licensed under Creative Commons)

Check the following visual resources titled "What Are Systematic Reviews?"

 

Image: https://pixabay.com 

Steps to conducting a systematic review: PIECES

P: Planning -  the methods of the systematic review are generally decided before conducting it.  
 
I: Identifying - searching for studies which match the preset criteria in a systematic manner
E: Evaluating - sort all retrieved articles (included or  excluded) and assess the risk of bias for each included study
C: Collecting/combining - each study is coded with preset form, either qualitatively or quantitatively synthesize data.
E: Explaining - place results of synthesis into context, strengths and weaknesses of the studies 
S: Summarizing - report provides description of methods and results in a clear and transparent manner

 

Source: Foster, M. (2018). Systematic reviews service: Introduction to systematic reviews. Retrieved September 18, 2018, from http://tamu.libguides.com/c.php?g=574702&p=4298724