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Edward G. Miner Library

Evidence Based Dentistry: Using PICO(T)

Resources for use in class

The "Silent T" in PICO(T)

Two additional important elements of the well-built clinical question to consider are

  • the type of foreground question
  • the type of study (methodology)

This information can be helpful in focusing the question and determining the most appropriate type of evidence.

Foreground questions can be further divided into questions that relate to therapy, diagnosis, prognosis, etiology/harm.

  • Therapy: Questions of treatment in order to achieve some outcome. May include drugs, surgical intervention, change in diet, counseling, etc.
  • Diagnosis: Questions of identification of a disorder in a patient presenting with specific symptoms.
  • Prognosis: Questions of progression of a disease or likelihood of a disease occurring.
  • Etiology/Harm: Questions of negative impact from an intervention or other exposure.

Knowing the type of foreground question can help you select the best study design to answer your question. You always want to look for the study design that will yield the highest level of evidence. Consult the pyramid on the Study Designs tab (click the image to enlarge it) and the definitions below.

Formulating a Well Built Clinical Question

According to the Centre for Evidence Based Medicine (CEBM), "one of the fundamental skills required for practising EBM is the asking of well-built clinical questions. To benefit patients and clinicians, such questions need to be both directly relevant to patients' problems and phrased in ways that direct your search to relevant and precise answers."

A well-built clinical foreground question should have 4 - 5 components. The PICO(T) model is a helpful tool that assists you in organizing and focusing your foreground question into a searchable query. Dividing into the PICO elements helps identify search terms/concepts to use in your search of the literature.

P = Patient, Problem, Population (How would you describe a group of patients similar to yours? What are the most important characteristics of the patient?)

I = Intervention, Diagnostic Test, Prognostic Factor, Exposure (What main intervention are you considering? What do you want to do with this patient?)

C = Comparison (Can be no treatment or placebo.) (What is the main alternative to compare with the intervention? Are you trying to decide between two drugs, a drug and no medication or placebo, or two diagnostic tests?)

O= Outcome (What are you trying to accomplish, measure, improve or affect? Outcomes may be disease-oriented or patient-oriented.)

T= Type (What type of clinical question is this? See the adjacent box on the "Silent T" in PICO(T).