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Systematic & Scoping Reviews : Methodology Behind the Search Strategies

This guide is primarily for students and other researchers conducting systematic reviews and scoping reviews for coursework, thesis/dissertation requirements, or for other research purposes.

What is a protocol?

A protocol is a plan for how your review will be conducted.  It sets out in advance:

  • The purpose or rationale behind conducting your study
  • The methodologies to be used (e.g. in finding reviews, in assessing the quality of reviews found, statistical methods, etc.)
  • Anticipated bias and how it will be addressed 
  • Determine in advance what outcomes you will be measuring (to avoid selective reporting of outcomes)
  • How will the data be synthesized
     

The registration of a protocol provides a means of ascertaining that the screening, selection and reporting in a completed review are based on the pre-defined eligibility criteria and the methodological approach outlined at the outset, rather than influenced by study findings.

Utilizing the PRISMA-P guideline and checklist in completing the protocol can optimize the quality of reporting. Making protocols publicly available increases transparency and can reduce duplication of effort. This is usually done in a registry (such as Prospero) or a dedicated journals (such as Systematic Reviews, Biomed Central, BMJ Open) during the planning stages of the review.

Check the following sources for protocols or published systematic reviews on your topic:

"The gold standard for identifying reporting biases is a comparison of the completed review with its paired protocol" (Moher, D., L. Stewart and P. Shekelle. 2016. Implementing PRISMA-P: recommendations for prospective authors. Systematic Reviews 5:15. doi: 10.1186/s13643-016-0191-y)

Protocols can be registered and/or published.  This allows for:

  • Peer review
  • Reducing duplication of effort
  • Increasing the transparency of research (e.g. reducing selective reporting of outcomes)

Example of a protocol for a systematic review
Cotic, Z., Rees, R., Wark, P. A., & Car, J. (2016). Factors influencing the implementation, adoption, use, sustainability and scalability of eLearning for family medicine specialty training: A systematic review protocol.  Systems Review,  5(1), 179.
Example of a protocol for a scoping review
Grudniewicz, A., Nelson, M., Kuluski, K., Lui, V., Cunningham, H. V., X Nie, J., . . . Upshur, R. E. (2016). Treatment goal setting for complex patients: Protocol for a scoping review. BMJ Open, 6(5), e011869.

Journals which publish protocols
BMJ Open
Systematic Reviews

Guidlelines and assistance for writing/creating a protocol

  1. Institute of Medicine describes what should be in a protocol in Sections 2.6 - 2.8 of the Finding What Works in Health Care:Standards for Systematic Reviews:  https://www.nap.edu/read/13059/chapter/4#48
     
  2. Cochrane Training provides an online presentation on how to prepare and write a protocol:
    http://training.cochrane.org/resource/writing-protocol
     
  3. Pages 29 - 33 in Doing a Systematic Review: A Student's Guide (http://go.utlib.ca/cat/9957699 ) provides basic guidance on writing a protocol
     
  4. PRISMA-P (Preferred Reporting Items for Systematic review and Meta-Analysis Protocols) provides a  checklist of items recommended for inclusion into reporting a protocol
    http://prisma-statement.org/Extensions/Protocols.aspx

 

Guidelines specific to a scoping review:

1. Chapter 2 "Development of a JBI Scoping Review Protocol" in the: Joanna Briggs Reviewers Manual for Scoping Reviews: http://joannabriggs.org/assets/docs/sumari/Reviewers-Manual_Methodology-for-JBI-Scoping-Reviews_2015_v2.pdf

 

Importance of registering a protocol

The journal Systematic Reviews has a series of articles and commentaries on the importance of PROSPERO, why registering systematic reviews makes sense, dispelling myths of protocol registration, knowledge synthesis and the CIHR, and more.

Collection of articles on importance of registering systematic reviews

 

Where can I register a protocol?

PROSPERO
International prospective register for systematic reviews  (some scoping reviews as well)

Cochrane Library;
International organization that produces and disseminates systematic reviews of intervention in health care (can filter search results to protocols)

Campbell Collaboration Library
Systematic reviews of the effects of social interventions