PICO searches and systematic reviews

PICO searches and systematic literature reviews

What is a PICO search?

PICO is a framework that is used to break a problem down into searchable components.

The term PICO is a mnemonic to help you remember the different elements, and often used in evidence based medicine (EBM) or evidence based practice (EBP). A PICO search is a search conducted on a research question that you have developed out of these elements.

PICO stands for:

  • Patient/Population/Problem
  • Intervention (cause, factor, treatment etc.)
  • Comparison
  • Outcome(s)

Breaking down a scenario into the PICO framework is an exercise in identifying key terms and words.

How do I conduct a PICO search?

To conduct a PICO search, you use the key terms as discovered through your analysis of the scenario. You can then build a search using these different elements as search terms in a database. One great database for conducting a PICO search is Medline.

Medline allows you to search by keywords or MeSH (medical subject headings). You can search one or both depending on how broad you would like your search to be. Medical subject headings may be slightly different to your original search term (e.g. the MeSH for ‘lung cancer’ is ‘lung neoplasms’).

You can refine your search by applying limiters. There are several different kinds of limiters available in Medline including age of patient, publication date, source type and several others.

Watch the tutorial

For more detailed information, search tips, and a step by step example on PICO searching in Medline, see the video tutorial (32 minutes).


What is a systematic literature review?

A systematic literature review (SLR) is a detailed review and analysis of all key primary research in relation to a focused question, such as one developed using the PICO framework. It is a more detailed and critical review than literature review. For more information on the differences between a systematic review and a literature review, see the Medicine and Health Guide.

How do I conduct a systematic literature review?

To conduct an SLR, you must carry out numerous searches relating to your focus question. You will need to keep track of all your searches and the search strategies you have used.
You can use a SLR tracker to do this. You can also save your searches inside some databases such as Medline. See the above tutorial for information on how to do this. Saving your searches allows you to revisit them, review your search strategy and also to combine several different past searches.


Further resources