The purpose of a systematic review is to answer a clear and focused clinical question. Translating a knowledge gap into an answerable and soundly constructed clinical question is an important skill.
The review question should be defined at the beginning your systematic review. A well formulated review question will help determine your inclusion and exclusion criteria, the creation of your search strategy, the collection of data and the presentation of your findings. A sound clinical question:
The clinical question should always be:
Review questions may be broad or narrow in focus.
It is important to formulate your research question with care so as to avoid missing relevant studies or collecting a potentially biased result set.
PICO are useful tools for defining clear, focused clinical questions and developing a review protocol. Before defining your question using PICO, you should check that your question has not already been the subject of a systematic review.
What if you want to change things later?
A protocol for a systematic review should only be modified if it becomes clear that there are alternative ways of defining your population, intervention, outcomes or study designs.
From: Murdock University Systematic Reviews Research Guide