5: Getting started
This section introduces you to key skills for using a systematic approach to writing and conducting a review that does not involve a meta-analysis. Rather, the focus will be performing narrative synthesis, which is typically used in all types of reviews.
Skills used in reviews are highly transferable to other common tasks in professional practice. Developing skills takes practice; it is not something that is simply switched on after you have done it once successfully – skills will develop with practice.
We start by exploring iterative processes to develop a research question (or research objectives) and the PICO and SPIDER methods.
Developing research questions
Before starting any review, you need to be clear about why a review of the research evidence is needed. The purpose of a review can be framed as a research question or as research objectives. These can be broad or specific, depending on the purpose of the review.
Research questions are often clearest for reviews asking a specific clinical question. For example, a review can ask about the best drug or right dose to use for particular conditions or for particular patient groups.
Further reading
Cross and colleagues[1] provide a good explanation on developing research questions, particularly for clinical questions.
When the purpose of a review is broader, such as when it is being used to identity different policy options or possible approaches in future primary research, the review research question will be correspondingly broader.
A specific question can be easier to answer, but only if there are sufficient studies available. The focus on the research question is important, as it determines the purpose of the review, which guides how the review is conducted and the results interpreted.
Without a well-developed research question, it is not possible to know if a review has met its purpose. Developing a research question, particularly in new areas of study, can be an iterative process in the early stages of a review. This means that questions may be refined after preliminary searches are conducted. However, retrofitting a research question after the review process has been completed raises issues of bias.
Further reading
Learn more about how to effectively formulate research questions by visiting this guide on research question development.
Research tools
Over time, researchers have developed tools in the form of mnemonics, which are words to help you remember what you need to include. Two commonly used tools are PICO and SPIDER.[2]
PICO
The PICO mnemonic and its variations PECO or PICOT are useful tools.
| PICO | PECO | PICOT |
|---|---|---|
| Population/People | Population/People | Population/People |
| Intervention | Exposure | Intervention |
| Comparison | Comparison | Comparison |
| Outcome | Outcome | Outcome Time |
PICO, in particular, is increasingly used in health-related studies to help craft research questions or develop research objectives. As a mnemonic, PICO acts to remind you of the different elements that need to be considered when thinking about the purpose of a review and subsequent questions or objectives.
Note that not all the elements are always present in research questions. For example, research questions usually include the study population, intervention/exposure and outcome. However, in broad research questions the comparison element may not be included, although it might be implied in terms of interpreting the research findings included in the review, in the context of comparison to the general population or usual practice.
A broad research question could ask what sort of interventions might work for a particular group, whereas a narrow research question would ask about a specific intervention for a specific group or setting.
SPIDER
The SPIDER mnemonic is sometimes used as an alternative when only qualitative studies are included in a review.
| SPIDER |
|---|
| Sample |
| Phenomenon of Interest |
| Design |
| Evaluation |
| Research type |
H5P activity: Framing review questions as PICO components
Table 1 shows how research questions from existing reports and reviews in the grey literature can be framed as PICO components. These examples use broad, exploratory research questions. Findings from these reviews can be used to frame more specific questions in subsequent studies.
Sometimes the intervention element can be better framed as an exposure (e.g. experience of mental health), and the comparison component is not necessarily included in the research question; rather, it is implied, particularly when the comparison group comprises other people without the experience or condition that the review intends to explore.
H5P activity: From PI/ECO to research question
Test your understanding of PICO elements by looking at the following research questions, framed as broad questions for a review.
- Cross, N. B., Craig, J. C., & Webster, A. C. (2010). Asking the right question and finding the right answers. Nephrology, 15(1), 8–11. https://doi.org/10.1111/j.1440-1797.2009.01264.x ↵
- Cooke, A., Smith, D., & Booth, A. Beyond PICO: The SPIDER tool for qualitative evidence synthesis. Qualitative Health Research, 22(10), 1435–1443. https://doi.org/10.1177/1049732312452938 ↵
Use of statistical methods to combine data from studies included in a systematic review. https://latrobe.libguides.com/systematicreviews
Literature produced by informed expert bodies but not published by an external publisher. https://latrobe.libguides.com/greyliteraturehealth
