All systematic reviews start with a strong, concise research question. This serves as the back-bone for a good search strategy, as it determines the structure and sequence for your literature searches.
Commonly preclinical SR research questions follow a PICO or PECO stucture:
- (P)opulation, (P)articipants, or (P)roblem: What are the characteristics of the population or participants (species, sex, developmental stage, risk factors, or for human participants demographics, pre-existing conditions, etc)? What is the condition or disease of interest?
- (I)ntervention or (E)xposure: What is the intervention or exposure under consideration for this population?
- (C)omparison: What is the alternative to the intervention (e.g. placebo, different drug, surgery)?
- (O)utcome: What are the relevant outcomes (e.g. quality of life, change in clinical status, morbidity, adverse effects, complications)?
There are other research question structures depending on your area or topic of interest, for example, diagnostic test reviews, and prognostic reviews. For more information, see this article on Formulating Review Questions.
It is important that you engage stakeholders early on in the review phase to ensure the research question and findings from the review are relevant. Consider the following: - Who will use the results of your systematic review? - From their perspective, what are the relevant questions to ask?
For reference, see examples of research questions for published reviews.
“What is the effect of antidepressants compared to vehicle or no treatment on infarct volume in animal models of ischaemic stroke?”
- P - Animal models of ischaemic stroke
- I - Antidepressants
- C - Vehicle or no treatment
- O - Infarct volume