How can we ask questions using PICO?

A 65-year-old man presents to his GP with vertigo. He has been experiencing dizziness and a spinning sensation for the past few weeks. The vertigo is usually triggered by changes in head position, such as when lying down or getting out of bed. He has also been experiencing nausea and vomiting.

The GP takes the patient's medical history and performs a physical examination. He learns that the patient has been diagnosed with benign paroxysmal positional vertigo (BPPV) and is currently taking betahistine. The GP uses PICO to frame the following question:

In 65-year-old man with benign paroxysmal positional vertigo (BPPV), does betahistine reduce the frequency and severity of vertigo episodes compared to placebo?

PICO stands for Patient, Intervention, Comparison, and Outcome. It is a framework for asking clinical questions in a way that is specific, measurable, achievable, relevant, and time-bound.

Patient/Population: Who is the group of people being studied? This could be a specific age group, gender, or medical condition.

Intervention: What is the treatment or intervention being investigated? This could be a new drug, surgery, or lifestyle change.

Comparison: What is the intervention being compared to? This could be a placebo, standard of care, or another intervention.

Outcome: What is the desired outcome of the intervention? This could be a clinical improvement, such as reduced pain or increased survival, or a patient-reported outcome, such as improved quality of life.

PICO questions are useful for clinicians, researchers, and patients alike. They can help to focus the search for evidence and to design research studies. For example, a clinician might use a PICO question to decide whether to prescribe a new drug to a patient. A researcher might use a PICO question to design a clinical trial to compare two different treatments. And a patient might use a PICO question to ask their clinician about the best way to manage their condition.

Here are some examples of PICO questions in medicine:

• Prevention: In adults with high blood pressure, does taking lisinopril reduce the risk of stroke compared to placebo?
• Diagnosis: Is the D-dimer test more accurate in diagnosing deep vein thrombosis than the Wells score?
• Prognosis: What is the long-term survival rate for patients with stage II lung cancer who are treated with surgery?
• Etiology: What are the risk factors for developing type 1 diabetes in children?
• Treatment: In adults with heart failure, is treatment with metoprolol more effective in reducing mortality than treatment with carvedilol?

Benefits

• Improved clarity and focus: PICO questions help to clarify and focus the question being asked. This is because they require the person asking the question to think about all of the relevant factors, such as the patient population, intervention, comparison, and outcome.
• More efficient search for evidence: PICO questions can help to make the search for evidence more efficient. This is because they provide a specific framework for searching for relevant studies and data.
• Better decision-making: PICO questions can help to lead to better decision-making. This is because they force the person asking the question to consider all of the relevant factors and to weigh the evidence carefully.

Risks and pitfalls

PICO questions are a valuable tool for asking clinical questions in a specific and focused way. However, there are some potential risks and pitfalls associated with PICO questions, including:

• Oversimplification: PICO questions can sometimes lead to an oversimplification of complex clinical problems. This is because they require the person asking the question to reduce the problem to a few key elements.
• Bias: PICO questions can sometimes be biased, depending on how they are framed. For example, a question that is framed in a way that favors a particular intervention is more likely to produce results that favor that intervention.
• Difficulty answering: PICO questions can sometimes be difficult to answer, especially if the evidence on the topic is limited or inconclusive.

A clinician might use a PICO question to decide whether to prescribe a new drug to a patient. However, if the PICO question is oversimplified, the clinician may not consider all of the relevant factors, such as the patient's other medical conditions or the potential side effects of the drug.

Examples

Treatment:

• In adults with hypertension, is treatment with lisinopril more effective in reducing the risk of stroke than treatment with amlodipine?

Prevention:

• In adults at high risk of cardiovascular disease, does a plant-based diet reduce the risk of heart attack compared to a standard Western diet?

Diagnosis:

• In adults with suspected pneumonia, is the C-reactive protein (CRP) test more accurate in diagnosing pneumonia than the white blood cell count (WBC)?

Prognosis:

• In adults with heart failure, is the 1-year mortality rate lower for patients who are treated with beta-blockers than for patients who are not treated with beta-blockers?

Reference

Eriksen, M.B., Frandsen, T.F., 2018. The impact of patient, intervention, comparison, outcome (PICO) as a search strategy tool on literature search quality: a systematic review. J Med Libr Assoc 106, 420–431. https://doi.org/10.5195/jmla.2018.345

Howard, C., n.d. Subject and Course Guides: Evidence Based Medicine: Asking Clinical Questions [WWW Document]. URL https://researchguides.uic.edu/ebm/pico (accessed 10.03.23).