A protocol is a document that serves as a work plan for your review that describes the rationale, hypothesis, and planned methods of the review. Your protocol should be prepared before you start your review, even if things change along the way. Following a protocol allows for transparency, reproducibility, and minimizes biases. Many journals now require submitted systematic reviews to have registered protocols.
For systematic reviews, the PRISMA website provides several sources of guidance on writing a protocol.
For scoping reviews, the Joanna Briggs Institute provides guidance for writing a protocol in section 11.2 of their chapter on scoping reviews. Resources for scoping reviews can be found through the JBI Scoping Review Network.
In general, your protocol should have the following elements:
(Adapted from: Booth, A., Sutton, A. and Papaioannou, D. (2016). Defining the scope. Systematic Approaches to a Successful Literature Review, 2nd edition.)
One of the most common mistakes researchers make when conducting a review is failure to develop a robust protocol in advance of beginning searches or abstract review
Checklist and explanation of what should be included in a systematic review protocol.
Can be used across review types (i.e., scoping review, review of qualitative studies, meta-analysis, or any other type of review)
Template for systematic review protocol (Durham University).pdf
Once you have written your protocol, consider registering it with an organization or publishing it in a journal. Listed below are a few example resources:
PROSPERO - Initiated in early 2011, this international database allows free registration of systematic reviews of interventions and strategies to prevent, diagnose, treat, and monitor health conditions in humans, for which there is a health-related outcome. At the present time, PROSPERO does not accept scoping review protocols.
More information and guidance on registering in PROSPERO can be found on their website.
Scoping reviews may not be registered with PROSPERO. Currently, they can be registered with the Open Science Framework or Figshare.
BioMed Central will consider protocols of any type of research for publication, following the standard peer review.
BMJ Open "will consider publishing without peer review protocols that have formal ethical approval and funding from a recognized, open access advocating research-funding body". Otherwise, protocols are peer reviewed.
Like systematic reviews, scoping review protocols can be published in some journals.
This open access title publishes protocols of systematic reviews broadly related to health sciences.