Forming your question
Systematic reviews answer specific questions, using the most evidence-based, unbiased method possible.
Defining your systematic review question is an important step - it will impact what type of evidence you use.
A review question can take one of three forms, depending on the evidence type needed.
Quantitative
Cause and effect relationships with specific answers or outcomes. Research methods generally involve sampling, statistics and meta-analysis.
Qualitative
Seeking understanding or meaning. Research methods generally involve interviews, surveys, observation or analysis of documents or artefacts, and grouping information into themes (meta-synthesis).
Mixed Methods
Broader questions that require both qualitative and quantitative evidence. This type of review may include both a meta-analysis and a meta-synthesis.
A tool which can help you formulate either a quantitative, qualitative or a mixed-methods question is a mnemonic.
Mnemonics are question frameworks abbreviated into a catchy, easy-to-remember words. They are not essential, but can help you identify the key 'ingredients' needed to answer particular types of questions. For example, a quantitative systematic review will often require a Population, and an Intervention. The PICO mnemonic detailed below requires both of these to form a question.
PICO
PICO is the most commonly used mnemonic. It is suitable for quantitative questions where you are investigating cause and effect.
PICO example question
Is (I) hand washing or (C) hand sanitiser more effective in preventing the spread of the (O) common cold amongst (P) school children?
Tips
- A mnemonic is there as a guide only - don't worry if your question doesn't fit in neatly. The main thing is being able to divide your question into separate concepts.
- Not every concept needs to be present in your question - for example, it's common to not have a comparison.
Here are some more mnemonics you can use
Remember that you do not have to have a concept for every letter.
Quantitative
PICOT – Population, intervention, comparison, outcome, time factors
e.g. How effective are (I) nicotine patches compared to (C) support groups for (O) smoking cessation in (P) chronic smokers within the (T) first year of quitting?
Qualitative
PICo – Population, phenomenon of Interest, context
e.g. What are the experiences of (P) school children undertaking (I) online learning during (Co) lockdown in Australia?
PICOS – Population, intervention, comparison, outcome, study design
e.g. (P) Type 2 diabetes (I) Lifestyle changes (C) Metformin (O) Blood glucose management (S) Patient Interviews
SPIDER – Sample, phenomenon of interest, design, evaluation, research type
e.g. What are barriers to long-term carers utilising respite care programs?
(S) Carers (PI) Utilisation of respite care programs (D) Focus groups (E) Barriers (R) Qualitative
Mixed-methods
PICo – Population, phenomenon of Interest, context
e.g. What are barriers and facilitators for (P) caregivers accessing (I) respite care in (Co) Australia?
Hot tips
- A mnemonic is there as a guide only - don't worry if your question doesn't fit in neatly. The main thing is being able to divide your question into separate concepts.
- Not every concept needs to be present in your question - for example, it's common to not have a comparison.
Scoping searches
Scoping searches
Before formulating a research question, it's best to run some scoping searches to see what research exists. This will help give you an idea of what kind of question you might like to ask.
If your research question is health-related, a great database for these kinds of scoping searches is PubMed. Otherwise, you may want to consider using a database like Google Scholar for your scoping search.
Have a look at our quick PubMed tutorial below for some search tips:
- PubMed This is a key database used by health professionals around the world to find the latest research. Managed by the National Library of Medicine and is one of the largest health databases in the world. Contains the content in Medline.
Tips
- Investigate a topic which interests you!
- The titles and abstracts will tell you a lot about research themes and research directions - have a brief read through them for inspiration.
- A scoping search will also help you identify synonyms for your systematic search.
Know your topic
Check for existing reviews
If there is a systematic review already published or underway on your topic you may need to reconsider your question.
To check, search in multi-disciplinary databases. We suggest:
- Google Scholar
- Web of Science
- Scopus
To check if there is a systematic review that is in progress, check the main study registries:
Searching for existing reviews or protocols does not require a comprehensive search strategy. Use keywords in your search which represent your main concepts in your topic.
e.g. "green tea" AND cancer AND "systematic review"
Searching for systematic reviews
Chapter Summary
✅ Learnings
- Systematic Review questions come in three types: quantitative, qualitative and mixed methods.
- Most systematic reviews use a conceptual tool called a mnemonic to structure their questions. PICO is the most prevalent mnemonic in Health disciplines, but there are many others.
⚠️ I'm stuck!
Is my review quantitative, qualitative or both?
Systematic Reviews synthesise data from multiple studies. Focus on the data you are trying to combine and identify it.
It might be useful to read a mixed method review, which includes both kinds, to get a sense of each data type and how they can be used.
How do I structure my research question with PICO?
There's more detail and examples if the UTS Library Guide to Evidence-Based Practice, including templates
My question doesn't fit well into PICO!
There are many other mnemonics. Check the mnemonic section above. There's an extra tab with lots of other options. If none of these fit, then it's okay to simply identify the key concepts.
🛑 Stop and Review
My review is:
The mnemonic I am using is:
Click the next button to continue. ►