P I C O Questions

A clinical question is simply a question which you ask to help improve your clinical care. The need motivating a focused clinical question is, essentially, "How well does this treatment or diagnostic test work?" Clinical questions could arise in situations such as the following:

  • You become uncertain, during a patient encounter, about the desirability of a particular diagnostic or therapeutic choice.
  • You encounter a product advertisement in a journal in which you are encouraged to purchase and use a particular technology for your patients.
  • You receive a brochure promoting a continuing education course advocating a particular device or method to diagnose, prevent, or treat oral disease.
  • Your patient asks a question about a treatment they have read about in a consumer publication or an advertisement.

You should not be embarrassed about having frequent clinical questions or uncovering gaps in your clinical knowledge. Even the most experienced clinicians regularly raise such questions and uncover knowledge gaps.

A well-focused question has four elements. Use the acronym PICO to remember them.

P: The Patient or Problem

What problem or patient are you planning to treat or diagnose?

  • Briefly describe only the most pertinent features of your patient and/or their problem.
  • Examples:
    • Elderly type 2 diabetic;
    • Child with primary dentition and high caries risk;
    • Hypertensive middle age patient;
    • Healthy young adult with recent third molar extraction

I: The Intervention

What diagnostic test or treatment method are you most interested in using? State the diagnostic test or treatment you are considering using on behalf of the patient.

  • Diagnostic Examples:
    • Fiberoptic transillumination;
    • Brush biopsy
  • Therapeutic Examples:
    • Occlusal splint;
    • Class 2 amalgam restoration;
    • Scaling and root planning;
    • 800 mg ibuprofen

C: The Comparison Intervention

You can never know how well a treatment or diagnostic test (your Intervention, described above) works unless it has been systematically compared to another treatment or diagnostic test. This is your Comparison.

  • Diagnostic Examples (in comparison to the examples listed above):
    • Bitewing radiography;
    • Incisional surgical biopsy
  • Therapeutic Examples (in comparison to the examples listed above):
    • Class 2 composite restoration;
    • Personal oral hygeine;
    • 300 mg acetaminophen;
    • Behavioral therapy
  • Note that the Comparison could, in some cases, be "placebo," "no treatment," or "watchful waiting" or similar.

O: The Outcome

This is the result or endpoint that is most important to you and to your patient.


  • Reduced incidence of dental caries;
  • Reduced temporomandibular pain;
  • Early detection of squamous cell carcinoma;
  • Early detection of interproximal caries

Your question should include all four of the above (Patient/Problem, Intervention, Comparison, and Outcome) stated in one sentence. In sentence form, your question should read something like this:

For a patient with (Problem), how does (Intervention) compare to (Comparison) with regard to (Outcome)?

The four elements need not be stated in this order, but all the elements should be included. If you take the time to do this, the format will help you search the appropriate sources, such as journal databases, quickly and effectively for the evidence you need to answer your question.

Poor Examples: The Unfocused Question

A problem with questions that arise in clinical practice is that sometimes these questions occur to us in unfocused fashion. Finding answers to questions like these can be frustrating and unnecessarily time-consuming. Examples of UNFOCUSED questions include:

  1. How effective are occlusal splints?
  2. Does chlorhexidine cure gingivities?
  3. Does fiberoptic transillumination detect dental caries?
  4. Does flossing prevent periodontitis?
  5. How well does behavioral therapy treat temporamandibular disorder?
  6. What is the best treatment for pericoronitis?

The solution to this problem is to rephrase the question in a FOCUSED QUESTION format.

Why is This Important?

The structured format of the FOCUSED CLINICAL QUESTION promotes a more reliably efficient and effective search for evidence with which to answer your question. Failing to focus your question can waste your time during the search for evidence. Even if you have an information specialist, such as medical librarian, help you with your search, you will get better results if you first state your question in a FOCUSED QUESTION format. Furthermore, stating your question in PICO format will help you more readily recognize the most appropriate article citation(s) as they appear in your PubMed search results.

Good Examples of Focused Questions

Let's take the six unfocused questions above and edit them into focused (PICO format) questions.

  1. Are canine-guided occlusal splints more effective than nonoccluding splints in reducing temporamandibular pain in middle-aged females?
  2. Does twice-daily chlorhexidine rinse in young adults reduce the severity of gingivitis, compared to personal oral hygiene alone?
  3. How does fiberoptic transillumination compare to bitewing radiography in the detection of early interproximal dentin caries in adults?
  4. Does daily patient flossing reduce the incidence of periodontal bone loss in healthy adults compared to daily patient brushing only?
  5. Does behavioral therapy reduce temporomandibular pain more effectively than nonsteroidal anti-inflammatory medication?
  6. Which is more effective in relieving the symptoms of third molar pericoronitis: saline irrigation or systemic antibiotic

A table to help you write a PICO question

For links to other tutorials on PICO questions, see: The University of Washington or the ACP Journal Club.