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Nursing Research Guide

Guidance for Nurses and Allied Health Researchers

PICO— forming clinical questions

PICO (pee-co) 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 a specific, relevant clinical question, which is the foundation for formulating a database search strategy (and evidence-based care). Sometimes also seen as PICOT/PICOTT.

After we understand the background of a research topic we need to dig into more specifics. This is where PICO questions serve 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.

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 and often the comparison is implied.

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?

Sometimes includes—

T: Time or Timeframe

How long will it take to reach the desired outcome? 


TT: Type of Question and Type of Article

Sometimes determining the type of question (therapy, diagnosis, etc.) is included and then the type of article best suited.

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?

PICO Resources

University of Canberra Library  Guide to forming a PICO-format clinical question.

University of Minnesota Library Resources for Evidence Based Practice- The "Well-Built Clinical Question"

San Diego State University Library- Breaking Down PICO

Oregon Health & Science University-  Asking Your Question (PICO)

Northern Arizona University- Evidence Based Practice- Write a focused clinical question

Clinal Information Access Portal of NSW, Australia-  Clinical examples using PICO

New York University Libraries- Foreground (PICO) Questions

Type of Question & Type of Study

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

Under each you will find the types of clinical studies better suited to answering questions in each domain—

Diagnosis: How to select and interpret diagnostic tests

  • Prospective, blind comparison to gold standard

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

  • Randomized Controlled Trials (RCTs)

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

  • Randomized Controlled Trials (RCTs) > cohort > case control > case series

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

  • Cohort (follow-up) > case control > case series

Etiology: How to identify causes for disease, including genetics

  • Cohort > case control > case series