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Systematic reviews and other evidence synthesis projects

To Do during this step

  • Write your protocol
  • Register your protocol

Pro tip: If you already have some relevant articles, review them to develop your data extraction strategy. What data will you need to extract to answer your question?

About protocols

What is a protocol?

A document that  "describes the rationale, hypothesis, and planned methods of the review. It should be prepared before a review is started and used as a guide to carry out the review." - PRISMA protocol guidelines

Why write a protocol?
  • Provides a foundation...
    • For the research:
      • Acts as a guard against arbitrary decision-making during review process
      • Addresses methodological issues at the beginning of the process
    • For the project:
      • Acts as road map for process
      • Identifies the project's scope, resources, team members, and timeline
  • Improves the quality and rigor of the review
    • Improves transparency of completed review
    • Enables readers to assess for selective reporting or deviation from planned methods.
  • May be a requirement for publication
  • Complies with guidelines & standards
Why register a protocol?
  • Establishes a public document stating that you are working on a topic
  • Reduces wasteful duplication of reviews
  • Creates opportunity for peer review to improve review methodology
  • Potentially increases visibility to potential researchers or editors
  • Establish credibility and accountability
  • An increasing number of journals require it

A 2018 study identified an association between registration of a protocol in PROSPERO and the overall review quality of its systematic review based on the AMSTAR tool. The authors speculated that the time spent planning and documenting all of the review procedures might indirectly result in more robust methods. But regardless of where you register, completing a protocol is time well invested.

When should I register?

Review the checklist for the PRISMA-P protocol guidelines or the PROSPERO registration form. Can you complete all the applicable items? If so, you may be ready to register. You will be expected to stick to your protocol just as if it were a lab protocol, so make sure you have documented the process you intend to follow.

Writing your Protocol

Prepare to answer the following:

  • Review title & research question
  • Anticipated start date & completion date
  • Team members & roles
  • Search strategy (not necessarily full search string)
  • Inclusion & exclusion criteria for studies
  • Data extraction strategy
  • Risk of bias assessment/approach to critical appraisal
  • Tools that will be used
  • Dissemination plans

Here are some of the standard protocol templates. If you are conducting a review according to a specific standard, you must use that standard's protocol guidelines. If you are not writing to a specific standard, you may still use a standard's guidelines if they are appropriate to your topic, or use PRISMA-P.

  • PRISMA for systematic review protocols (PRISMA-P)
    The Preferred Reporting Items for Systematic Review and Meta-Analysis Protocols (PRISMA-P) was developed to improve the quality of systematic review protocols and facilitate registration by providing authors with a minimum set of items to be included in the protocol. The 17 checklist items pertain to the administrative elements, rationale and objective, and methods of the review, including risk of bias assessment and data synthesis. The accompanying Explanation and Elaboration paper provides more detail about each of the items.
  • Cochrane: Standards for the Reporting of Protocols of new Cochrane Intervention Reviews
    Systematic reviews performed according to the Cochrane standards are required to have a protocol that follows the standards described in Methodological Expectations for Cochrane Intervention Reviews (MECIR).
  • JBI
    Protocols for different types of systematic reviews written according to JBI standards, and also for scoping reviews.
  • Campbell Collaboration
    Campbell reviews and their protocols are conducted using templates in RevMan review support software. See Chapter 5 in the Campbell policies and guidelines for a list and descriptions of the fields.

If any of the elements are confusing or you're not sure how to do them, you can schedule with a librarian to discuss it further.

Equity Considerations

From your research question development, your protocol can include detailed elements of intent. Being as specific as possible, this is another way to mention some of the strengths and weaknesses within current research and highlight aspects of the health and social gradient that need to be addressed. Examples of elements to include are the following:

  • Include areas where research has taken place (rural, urban, metropolitan, cities, etc.)
  • Include demographics of people included and those excluded (socioeconomics, race, ethnicity, etc.)
  • Include information about the surrounding environment that may provide context or relevance (food deserts, topography, climate, agriculture)

This may seem like a lot of work and very detailed, but even the mention of these elements is very crucial to addressing much larger issues within research and this is a way you can play a role in combatting inequities in medical and health research.

Registering your Protocol

Where you register your protocol depends partially on your type of review and your topic. Here are some of the options.

Should I use PROSPERO or PRISMA-P for a systematic review?

They serve different purposes: PROSPERO specifies its required fields for registering your review, but doesn't go into a lot of detail about the content. PRISMA-P provides more guidance on the content, but is not a place to register your review. You can use the information in PRISMA-P to help you write your PROSPERO entries.