OC logo

OC Libraries

Skip to main content

Nursing & Allied Health

Research guide for Allied Health, ADN, BSN, and Human Services programs

What is PICO?

PICO is a mnemonic helps you to identify the key elements that need to be included  in a clinical question. PICO provides a strategy for you to formulate specific, relevant clinical questions, and it will also help you formulate a database search strategy.


After we understand the background of a research topic we need to dig into more specifics. This is where PICO serves health researchers. PICO helps us look at how a specific intervention can influence an outcome for a specific patient. You are moving from a research question to a clinical question- something that will help you determine how to care for patients.

Use the keywords from your background research combined with your PICO elements to begin searching databases for the research articles you need.


Applying PICO

 When you create a PICO question, you are actually thinking about how discrete elements of your topic relate to each other.

Here are some examples—

 Clinical Question: In infants born prematurely, compared to those born at full term, what is the subsequent lifetime prevalence of sensory deafness?

Clinical Question: Does hand washing among healthcare workers, compared to not washing hands, reduce hospital-acquired infections?

Clinical Question: Is Crixivan effective when compared with placebo in slowing the rate of functional impairment in a 45 year old male patient with Lou Gehrig's Disease?

Clinical Question: In pediatric patients with Allergic Rhinitis, are Intranasal steroids more effective than antihistamines in the management of Allergic Rhinitis symptoms?

The University of Canberra Library has a guide to forming a PICO-format clinical question.

Single Study Recommendations By Domain

Different types of research studies are better suited to answering questions in various domains of inquiry. Well-done Meta-Analysis or Systematic Reviews offer our best evidence-based answers; however, sometimes we need to seek out individual studies. In those cases, here are suggestions for the best type of single study by domain.

Diagnostic— Prospective, blind comparison to gold standard

Therapy— Randomized Controlled Trials (RCTs)

Prevention— Randomized Controlled Trials (RCTs) > cohort > case control > case series

Prognosis— Cohort (follow-up) > case control > case series

Etiology/Harm— Cohort > case control > case series



Elements of PICO

P: Population, Problem or Patient

Who or what is the question about? How would you describe a group of patients similar to yours? What are the most important characteristics of the patient/population/problem? This may include the primary problem, disease, or co-existing conditions. Sometimes the sex, age or race of a patient might be relevant to the diagnosis or treatment of a disease.

I: Intervention

What main intervention/treatment are you considering? What do you want to do with this patient? Prescribe a drug? Order a test? Consider surgery? What factor may influence the prognosis of the patient? Age? Co-existing problems? Genetic conditions? What was the patient exposed to?

C: Comparison

What is the main alternative intervention/treatment to the above being considered, if any? Are you trying to decide between two drugs, a drug and no medication or placebo, surgical techniques, or two diagnostic tests? Your clinical question does not have to always have a specific comparison.

O: Outcome

What are you trying to accomplish, measure, improve or affect? What are you trying to do for the patient? Relieve or eliminate the symptoms? Reduce the number of adverse events? Improve function or test scores?

Types of Questions

Well-constructed clinical questions help in focusing research and determining the most appropriate type of clinical evidence. Here are broad categories of clinical questions and descriptions of what they mean. 

Diagnosis : How to select and interpret diagnostic tests

Therapy : How to select treatments to offer patients that do more good than harm and that are worth the efforts and costs of using them

Prevention : How to determine the effectiveness of an intervention or exposure in preventing morbidity and mortality

Prognosis : How to estimate the patient’s likely clinical course over time and anticipate likely complications of disease

Etiology : How to identify causes for disease, including genetics