Scoping Reviews

What is a protocol?

A protocol is a detailed plan of the process created prior to starting work on your review. Protocols are less often required for scoping reviews than they are for systematic reviews, and authors have more flexibility with altering aspects of the process from their protocol once they begin digging into the data. It provides direction, helps avoid scope creep, and provides a framework for a review team to follow. Some elements within your protocol may change in the course of the review, and that is more expected in a Scoping Review than a Systematic Review, and you can note them in your methods section.

At the very least, a scoping review protocol should include:

• Introduction
  • Rationale
  • Objectives
  • Definitions
  • Research Question(s)
• Methods
  • Eligibility criteria
  • Information sources
  • Search strategy
  • Study selection process
  • Data extraction/analysis
• Data charting/synthesis

Eligibility criteria

Eligibility criteria, also known as inclusion/exclusion criteria, should be established before beginning your review.  Often, your eligibility criteria are determined by the framework used to develop your research question. For scoping reviews, the JBI manual recommends a PCC (population, concept, context), but PEO (population, exposure, outcome) is also popular. See the page on Research Questions for more about these and other frameworks.

Be sure you have a clear, defensible reason for each criteria you include. While it may be tempting to limit by date, by peer review, and by English language, these limitations introduce bias into your methodology. It is especially important for scoping review methodology to capture materials that would be filtered out by these criteria because the point is to cast a wide net to see the breadth of the literature on your topic. If you must include one of these criteria, be prepared to defend your decision in your manuscript.

Sample eligibility criteria:

Team & author roles

As part of your protocol, consider if you have an appropriately sized team for conducting a scoping review. Disciplines vary on team size expectations, however, there are some general best practices you may want to consider.

• 3+ team members involved in study selection process
  • It will also be helpful at this stage to outline how you will resolve conflicts regarding which studies meet eligibility criteria
• 2+ team members involved in data extraction and analysis
• Librarian involvement, including peer review of search strategies using PRESS guidelines.

Establishing team member roles in advance is extremely beneficial for smoothly conducting and documenting the review process.

Registering, publishing, or sharing your protocol

There are many reasons to identify a target journal for publication prior to beginning the project. One of them is that you will know the protocol requirements for that journal prior to submission. Some journals may require an a priori protocol. Some may require the protocol be registered, whereas others will only want to see that it is shared and accessible. 

Below are three different ways of making your protocol available. 

1. Registering, which provides a date, a persistent identifier you can cite in your manuscript, and versioning functionality.
2. Publication of protocols is offered by very few journals and almost if not exclusively in the health sciences. Publication makes it available and provides a unique identifier, but does not provide the option for updating and versioning of your protocol as you go.
3. Sharing through a repository is most common for scoping review protocols. Some repositories will automatically assign a persistent identifier for your protocol, others won't, so it helps to do some research in advance. All will provide some functionality for versioning.

Register

Publish

Share