As a health librarian, one of the things which final year and postgraduate students ask me about most often is PICO. But what on earth is PICO? Not, sadly, a droid from the Star Wars universe, but a tool used by researchers. Read David’s blog post to find out more…

What is PICO?

Well, let’s cut straight to the chase. Here’s a short video which can answer that question:

Didn’t watch the video? The super-short version is this: PICO is a tool developed to help medical researchers ask good questions. And it can also come in handy when preparing a literature search for a literature review or similar piece of work.

PICO stands for:

• Patient/Population – who should the research be about? This might include age, race or gender, or people with a particular health condition.
  
• Intervention – what is the health or medical professional doing? This could be an intervention to diagnose, prevent or treat.
  
• Comparison – what is the intervention being compared to? This element isn’t always present.
  
• Outcome – how can we tell whether the intervention had any effect?
  

Researchers consider each of these things to make sure that their questions are specific and focused. And they can also be considered when planning a literature search, to make sure that the most relevant information is discovered.

For example, if you are researching a particular drug (an Intervention), you could focus the topic by looking at adverse effects (Outcome) compared to another drug (Comparison) in elderly patients (Population). And then, when looking for information, you would make sure that you search for and select sources which cover the relevant Population, Intervention, Comparison and Outcome.

Alternatives to PICO

This is a fantastic tool for developing questions and literature searches for topics about health and medical interventions including surgical techniques, therapies or diagnostic tools. But even in health and medicine, not all questions are about this sort of intervention. That’s where other tools come in handy. SPIDER and SPICE are the two that I share with students the most often, though there are loads of them out there.

What is SPICE?

SPICE is often used by researchers in social care and public health. It stands for:

• Setting – where? This could be a location, or a healthcare setting such as the operating department or a GP surgery.
  
• Perspective – who? This might be service users, or it could be a specific group of professionals such as school nurses or podiatrists.
  
• Intervention, just like in PICO, though the concept of Intervention could be broader here and include environmental factors.
  
• Comparison – again, just like PICO.
  
• Evaluation – how is the impact of the intervention being measured?
  

What is SPIDER?

SPIDER is particularly useful for qualitative or mixed methods research which investigates people’s experiences of something. It stands for:

• Sample – the participants in the research.
  
• Phenomenon of Interest – what is it that the research will look at? This should be something which people can experience or have opinions about.
  
• Design – which research methods are of interest? Sometimes, a researcher only wants to read interview-based research, for example.
  
• Evaluation – what is being measured or evaluated? With SPIDER, this may be something subjective such as beliefs or understanding.
  
• Research type – qualitative, quantitative or mixed methods.
  

What is CIMO?

There are other tools for questions in disciplines outside of health care. For instance, CIMO can be used in questions relating to management. It’s quite tricky to use, but stands for:

• Context – this could be a group of people or a system, for example.
  
• Intervention – this could include an activity or a change in policy.
  
• Mechanism – this covers how people or systems respond to the intervention and the circumstances which contribute to this.
  
• Outcomes – the effects of the intervention.

No tool is better than another – the important thing is to use the right tool for the job. Just as it isn’t very helpful to use a hammer to cut a piece of wood in half, it isn’t helpful to use PICO if you want to research the lived experience of people with chronic illness.  

Finding out more

If you are planning a literature search as part of a literature review, research proposal or other extended piece of work, you may find the Learning Skills Hub module on Developing a search strategy useful. PICO is mentioned as part of this process.

As your librarians, we are always happy to talk to you about planning a literature search. Get in touch with your librarian through the Faculty pages on the Learning Skills Hub.

Further reading

If you want to read more, here are some sample references (all available via LibrarySearch) to dig in to these four tools:

For PICO: Miller, S.A. and Forrest, J.L. (2001) ‘Enhancing your practice through evidence-based decision making: PICO, learning how to ask good questions’, The Journal of Evidence-Based Dental Practice, 1(2), pp.136-141. doi: 10.1016/S1532-3382(01)70024-3

For SPICE: Booth, A. (2006) ‘Clear and present questions: Formulating questions for evidence based practice’, Library Hi Tech, 24(3), pp.355-368. doi: 10.1108/07378830610692127

For SPIDER: Cooke, A., Smith, D. and Booth, A. (2012) ‘Beyond PICO: The SPIDER Tool for Qualitative Evidence Synthesis’, Qualitative Health Research, 22(10), pp.1435–1443. doi: 10.1177/1049732312452938.

For CIMO: Denyer, D., Tranfield, D. and Van Aken, J.E. (2008) ‘Developing design propositions through research synthesis’, Organization Studies, 29(3), pp.393–413. doi: 10.1177/0170840607088020.

You will also find that many of the research methods books, particularly those that focus on literature reviews, will cover PICO and other similar tools.

This blog post was written by David Bedford, Academic Support Librarian at the Medway campus.