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The PICO Research Question

A strategy aimed at asking good clinical questions that will help in developing a research question

PICO Research Tips

  • The elements or components of your PICO question are what will assist you in your research. Your P, I, C, and O, (especially those nouns and adjectives) can all serve as search terms to help you find relevant literature. Use various combinations of your terms and connecting words (AND, OR, or NOT) to search for articles. Use quotation marks around phrases when searching.
  • There may or may not be research out there on the entirety of your PICO question. In other words, there may or may not be articles out there with a direct comparison of your research elements. If there are little to no articles with a direct comparison, the goal of PICO is for you to gather as much relevant literature about concepts within your question as possible. In doing so, you will eventually see patterns in the research that will allow you to do the comparison yourself, or lead you to an answer to your PICO question. 
  • When you have decided on a PICO question, do some initial or pre-research in databases and online. This allows you to see if there is enough research out there for you to answer your question before moving forward with the actual research. If not, you may need to go back to the drawing board and tweak some elements of your PICO. 
  • Develop synonyms or related terms to your PICO concepts. The MeSH database (Medical Subject Headings thesaurus) provides a great tool for this. In developing more keywords, this allows you to gather more relevant and quality literature. 
  • When gathering sources, make sure to compile more than the required number. As you evaluate articles, you will narrow down that pool to the articles that best fit your research.
  • When evaluating articles, begin with the title, the abstract (summary of an article), the introduction, and the conclusion. Skimming these can save you time and also clue you in on whether an article is relevant to your research. If you discover it is not, you can stop at any point in the process. If an article does seem relevant, then read the entirety of it. If you locate a high-quality article, check their references page. There you can potentially find more useful articles.
  • Go where the evidence leads you. Going into research, you may have a desired or expected answer to your PICO question. Don't let your bias inform your conclusions. 

PICO Keyword Chart

Example: In adults suffering from depression (P), how does St. John's Wort (I) compare to SSRIs (C) in improving depression symptoms (O)? 

Evidence Levels, Qualities, & Types

It is important to consider the types of evidence you are looking at when researching for a PICO question. If you are conducting a thorough literature review, you want to draw from as many levels and types of evidence as possible, including both quantitative and qualitative studies, unless otherwise indicated. The Hierarchy of Evidence Pyramid is a good visual tool indicating the different types of research and their intrinsic value. Another tool that is helpful in determining level or quality of evidence is the Johns Hopkins Evidence Based Practice for Nurses and Healthcare Professionals Model.

  • Qualitative - Textual data
  • Quantitative - Numerical data
  • Peer-Reviewed - Essentially an article screening process. If a nurse wants to submit an article to a particular journal, it is reviewed by experts within the nursing field, primarily for content. An article can be rejected, accepted, or revised before publication.
  • Systematic Reviews - A study that critically appraises and summarizes the evidence from the primary literature on a certain topic.
  • Meta-Analysis - A study that merges the findings of the relevant literature on a topic to arrive at a conclusion.
  • Randomized Controlled Trials (RCT) - Subjects are randomly assigned to one of two groups: the experimental group or the control/placebo group.