About protocols
Protocols are part of the systematic review process. A protocol is a statement that establishes the research question for youra systematic review and provides a detailed plan for how it will be answered. This includes:
- rationale
- objectives
- methodology (including eligibility criteria)
- how data will be managed and analysed
- any ethical or safety concerns.
A protocol is essential to:
- ensure the entire team is aware of and in agreement with the review question, methods, timelines, and search strategy
- enable communication with external stakeholders when seeking their contribution
- keep a systematic review focused and on topic
- ensure that ethical and copyright guidelines are followed closely.
Eligibility criteria
Eligibility criteria determine what evidence will be included or excluded in the systematic review process. These criteria are defined at the start of the systematic review process and are an essential element of the systematic review methodology.
Eligibility criteria must not change in the process of conducting a review, and must be carefully defined in your protocol in a way that allows enough flexibility without introducing additional bias.
Eligibility criteria may include:
- population characteristics (population, problem, age range or gender)
- study characteristics (design, setting or time frame)
- report characteristics (years included, language and publication status).
You can choose whether you formulate these criteria as inclusions or exclusions. You do not need to match each criterion with its opposite (e.g. include papers in English and exclude papers in all other languages).
Each criterion introduces a potential bias into your research. It’s important to justify each one in the methodology section of your systematic review.
Protocol templates
There are many protocol reporting standards available that outline the information required. These requirements will change depending on where the protocol is published.
Some of these templates include:
Registration
You must have a protocol if you are conducting a systematic review. If you are planning to publish your review in a journal, you must register it online. If you are completing a systematic review as part of your thesis, you do not need to publish your protocol. . Registering a protocol:
- informs other researchers of the review you are conducting, helping avoid duplication of effort
- avoids publication bias by ensuring that your research is published even if it finds negative results
- helps readers assess the quality and potential bias of the review, through comparison of the protocol and the published systematic review.
Platforms
There are several platforms that register and publish systematic review protocols. Many will have specific conditions and limitations that you need to be aware of and must take into consideration when registering.
Alternative platforms
You can submit the review protocol as a preprint on one of the following platforms that will provide you with a timestamp indicating that the protocol was created prior to starting the review:
Amending a protocol
A protocol may need to be changed after a systematic review has commenced. You may need to amend your protocol if:
- your anticipated completion date has changed
- key elements of your topic have changed, such as novel interventions, research methods, or terminology (Bayliss et al., 2016)
Any changes made should be reported and explained in an amendment to the protocol, as well as in the systematic review itself (Gough, Oliver, & Thomas, 2017). All registers have procedures for submitting amendments.
Refer to the search strategies and using databases pages for more details.
Getting help
Preparing a protocol requires the effort of an entire systematic review team. Make sure that you have consulted additional subject experts (such as your supervisors) before starting for their advice.
Honours students, Higher Degree Research students and staff members can consult an Academic Liaison Librarian for assistance with search strategies.