Evidence Based Medicine (EBM) - NJMS

Converting the need for information (about prevention, diagnosis, prognosis, therapy, causation, etc.) into an answerable question. When you see your patients in a clinic or hospital setting, you may encounter two types of questions: background or foreground questions.

Background questions ask for general knowledge about a condition, test, or treatment.

Have two essential components:

1. A question root (who, what, where, when, how, why) and a verb.

2. A disorder, test, treatment, or other aspect of health care.

Resources for background question: textbooks or point of care tools (such as UpToDate).

Foreground questions ask for specific knowledge to inform clinical decisions or actions. They are clinical research questions.

Normally have four essential components:

P: Patient, population, predicament, or problem.

I: Intervention, exposure, test, or other agent.

C: Comparison intervention, exposure, test, and so on, if relevant.

O: Outcomes of clinical importance, including time, when relevant.

PICO is the acronym of the four essential components of a clinical research question. We can use it to breakdown a clinical question or problem into concepts that enables effective searching within a database. Each letter of the acronym represents a different component of the clinical question.

Table 1. PICO Elements

In other words, you can use PICO to formulate your clinical research questions.

Question: In POPULATION, does INTERVENTION as compared to COMPARISON/CONTROL GROUP result in OUTCOME?

To answer foreground research questions, we need evidence from published research studies to support our decisions.

Clinical research questions, or foreground questions, can be further divided into questions that relate to therapy, diagnosis, prognosis, etiology/harm.

• Therapy/Treatment: 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.

When forming your question using the PICO framework, think about what type of question you are asking. Is it a therapy, prevention, diagnosis, prognosis, or etiology question? You may not need/find all the four PICO elements depending on your clinical question type. You may find all four PICO elements for therapy and diagnosis questions, but not for prognosis and etiology questions. 

Adopted from OHSU University Library Nursing Guide.