The review protocol is a critical document that outlines the methods and approach for conducting an evidence synthesis review, including eligibility criteria, data sources, and planned analysis. A registered or published protocol may be a requirement for publication, ensuring transparency, minimizing bias, and providing a guide for reproducibility.
Benefits of having a protocol for evidence synthesis:
A protocol generally includes the following information:
The resources below include general guidelines and/or templates for writing an evidence synthesis protocol. Some protocol registries (see box to the right) may have their own guidelines/templates.
What does it mean to have a "registered" protocol?
Registration or pre-registration simply means that you have saved your completed protocol to a database prior to starting your review.
When should I register my protocol?
Ideally, you should register your protocol before the literature searches have been executed. A protocol can be updated or changed if necessary. For example, you may need to update the search strategy to include new terminology or study filters, there may be new inclusion or exclusion criteria, or the roles of the team members may change. Most protocol registries will allow you to make updates and amendments. Be sure to keep track of these changes and provide a clear reason for making the change to maintain transparency.
IMPORTANT: Do not make changes to your protocol AFTER the data extraction phase, as this could be a source of bias.
How do I register my protocol?
Some registries, like PROSPERO, only accept systematic review protocols, while others may include additional functionality to track any research project from start to finish. Some registries are free, but others require a fee for registration. Many registries provide a unique identifier or persistent hyperlink (like a DOI) so that you can share your protocol with journals and stakeholders. The registry you choose will depend on the type of review you are doing.
List of Registries That Accept Evidence Synthesis Protocols
Some journals will also accept and publish evidence synthesis protocols. Check the author guidelines for the journal you are considering or see our library guide on Health and Life Science Research: Publishing for links to journal finder resources.
