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Systematic and Other Reviews: Defining a question

This guide contains information about systematic reviews and links to resources to help you conduct one.

Defining a question

 

Defining a question is an important step because the question determines how the review will be conducted. This page contains tips for coming up with a suitable question.

Formulating your question

 

A review question can take one of three forms, depending on the evidence needed to answer the question.

Quantitative

This kind of question is usually about cause and effect relationships and is looking for a specific answer or outcome. Research methods generally involve sampling and statistics to come to a conclusion about the effect of an intervention and so a quantitative systematic review will usually include a meta-analysis. 

Qualitative

This kind of question is about seeking understanding or meaning. Research methods generally involve interviews, surveys, observation or analysis of documents or artefacts. Qualitative systematic reviews will often result in a meta-synthesis to analyse themes.

Mixed Methods

 This particular question tends to be broader and can be answered by 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 frameworks which can help you identify what elements need to be present in your question. 

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.

A great database to use for these kinds of scoping searches is PubMed if your research question is health related, 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 searching tips:

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Tips

  • Another place you can scope in is Google Scholar.
  • 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.

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?

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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.