The next step after you have defined your question is to develop a systematic review protocol. The purpose of the protocol is to outline the methods you will be using and to provide a clear and explicit plan for your work. This is an essential part of a systematic review as it minimizes the possibility of arbitrary decision making and bias. Check Planning a systematic review? Think protocols from PRISMA to find out more about why protocols are important. It's highly recommended to check PROSPERO (or other relevant database) to ensure someone else hasn't already done the exact same review - see below for more information on PROSPERO.
The content in a protocol includes:
One of the key features of systematic reviews that differentiates it from other types of reviews is the use of criteria to include or exclude particular studies. Your eligibility criteria is what you plan to include and exclude from your review and should be guided by your research question and objectives. It needs to:
Some areas for your inclusion or exclusion criteria are:
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Demographic factors |
Age, sex, ethnicity etc. |
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Study design and duration |
What types of studies do you need to answer your question? |
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Measure |
Are you looking at a particular type of outcome measure? For example, functional abilities or quality of life? |
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Date range |
Only apply a date range if you are updating a previously published systematic review |
| Setting | School, hospital, community-centre etc. |
Consult the following for a comprehensve list of common inclusion/exclusion criteria for systematic reviews.
PRISMA for systematic review protocol (PRISMA-P)
PRISMA-P is 'a guideline to help authors prepare protocols for planned systematic reviews and meta-analyses that provides them with a minimum set of items to be included in the protocol.' - PRISMA-P Statement, p. 2.
Publisher requirement
While PRISMA-P is the preferred reporting item for systematic reviews and meta-analysis, there may be other specific requirements from your review body or publisher, for example:
To view criteria descriptions, hover the cursor over the green arrow, or download the file below.
It is a good practice to register your protocol, as you do not want anyone else to do the exact same review you are doing.
A good place to register a health review is PROSPERO. Once you register, your review will:
Where other disciplines may register a protocol as identified by Pieper and Rombey (2022).
References
Booth, A., Clarke, M., Dooley, G., Ghersi, D., Moher, D., Petticrew, M., & Stewart, L. (2012). The nuts and bolts of PROSPERO: An international prospective register of systematic reviews. Systematic Reviews 1(2), 1-8. https://doi.org/10.1186/2046-4053-1-2
Pieper, D., Rombey, T. (2022). Where to prospectively register a systematic review. Systematic Reviews, 11(8), 1-8. https://doi.org/10.1186/s13643-021-01877-1
Publishing your protocol
You can publish your protocol in the following journals and databases:
Many tables have been developed to show you the different levels of evidence.
The image below represents the hierarchy of evidence adapted from the National Health and Medical Research Council (NHMRC)
'Hierarchy of Evidence Pyramid' adapted from EBP & the Medical Librarian training manual, Duke University 2019, and Online EBM Page Generator, Dartmouth College and Yale University 2019, under the license CC-BY-NC.
Graphic courtesy of: https://guides.library.unisa.edu.au/SystematicReviews/Protocols
'Provide registration information for the review, including register name and registration number, or state that the review was not registered.'
'Indicate where the review protocol can be accessed, or state that a protocol was not prepared.'
'Describe and explain any amendments to information provided at registration or in the protocol.'