Getting started
Planning your review / knowledge synthesis project
Before you begin, ensure that you have the time and people to conduct a knowledge synthesis project.
- Time: Depending on the size of your review and the scope of your question, a systematic or scoping review may take a year or more to complete. If you need to complete a project within an academic semester, a scoping or systematic review may not be the best choice.
- Research team: At minimum, your research team should consist of two people to independently screen your results. Depending on the size of your review, it may be advisable to look for more team members to serve as additional screeners (and tiebreakers in the case of disagreement), subject matter experts, a statistician and a search specialist.
The research question
It is important to have a precise and well-defined question prior to starting your review. This will prevent bias by preventing you from re-framing your question based on the studies you find in your search. You will use your question to inform your search strategy and study selection criteria.
PICO — population, intervention, comparison, outcome — is a popular framework used to help construct your research questions.
For other frameworks, see:
- Using a framework to structure your question (from City, University of London)
- Framing a Research Question (from the University of Maryland)
- Booth A, et al. (2019). Formulating questions to explore complex interventions within qualitative evidence synthesis. BMJ Global Health, 4(S1): e001107. https://doi.org/10.1136/bmjgh-2018-001107
Inclusion and exclusion criteria
Your selection criteria place limits on your review and are determined before you begin searching. These criteria are informed by your Research Question and can be used to help shape your search. Inclusion and exclusion criteria can inadvertently introduce bias, so it is important to understand and be able to explain your rationale for your selection criteria.
Your criteria should be well defined so they can be applied consistently by all screeners. You are encouraged to pilot your criteria to ensure they are being applied as intended during screening. At this point, you should also develop a strategy for how screening disagreements will be resolved.
The University of Melbourne guide has a chart of common inclusion and exclusion criteria with brief descriptions, which may be helpful when determining criteria for your review.
Review protocol
The protocol is your research plan. It lays out your review rationale and question, methods (including search and study inclusion/exclusion criteria), and your plan for data analysis.
Protocols define your process to ensure a systematic approach and can help you stay on track with your review. As well, since systematic reviews and other knowledge synthesis projects can take a long time to complete, searching protocol registries before you begin and registering your protocol helps prevent duplication and wasted time.
Protocol databases
Some journals, like BMC Systematic Reviews, publish review protocols. However, there are also registries that allow you search protocols and upload your own.
- PROSPERO is a database and registry of protocols. They only accept protocols for systematic reviews, rapid reviews and umbrella reviews, in health topics or topics with a health-related outcome.
- OSF: Open Science Framework is an open-source collaboration software that allows you to publish your review protocols along with data files. If you are conducting a scoping review or a non-health related review, OSF is a good place for your protocol.
