Formulating a question

Translation of uncertainty into an answerable clinical question

Asking the right question is often the key to finding the research evidence needed to inform clinical practice. A carefully formulated question will increase the likelihood that a practitioner will find high quality evidence that can be incorporated into decision making about patient care.

Types of clinical questions (Bragge 2010; Cross 2010)

Intervention: relates to identifying or selecting treatment/s that are effective and worthwhile

Example scenario: You have a 53 y/o client who was recently diagnosed with type II diabetes and you were discussing with him the importance of changing his diet and lifestyle. He suddenly remembered a magazine article he read about Mediterranean diet and its potential benefits for people at risk of developing heart disease. He asked you if this type of diet will help with lowering his sugar level.

Aetiology: relates to the cause of a disease, or the relationship between a risk factor and the development of a disease/condition

Example scenario:  You have a patient who worked for more than five years in a silicon carbide industry. You would like to know if his work history has something to do with his diagnosis of lung cancer.

Diagnosis: seeks to find evidence that will determine the accuracy (e.g. precision, safety, etc.) of diagnostic tests or procedures in determining the presence or absence of a disease/condition

Example scenario: You have a patient who comes to you with fever, dyspnoea and severe cough.  On auscultation you heard crackles. You would like to know whether physical examination (i.e. auscultation) is as accurate as a chest x-ray in diagnosing pneumonia.

Prognosis: relates to the likely clinical course or potential complications of a disease/condition

Example scenario: You have a patient post-anterior cruciate ligament injury and he wants to know what factors will influence his return to football.

Exploration: seeks to answer the question ‘why’; concerned with the issue that often  impact the disease, treatment or health service, and is grounded in variations of human attitudes, opinions, feelings, thoughts or behaviours.

Example scenario:  You have a male patient who sustained traumatic brain injury following a motor vehicular accident.  You wondered what the impact of this condition might have on the patient and his family.

Further reading

Bragge P. Asking good clinical research questions and choosing the right study design. Injury 2010; 41(1):S3-S6.

Cross NB, Craig JC, Webster AC. Asking the right question and finding the right answers. Nephrology 2010; 15:8-11.


Elements of a well-built question

A good clinical question has four elements and PICO is a mnemonic or an abbreviation that is used to describe these components.

Population: Who are you interested in? (e.g. people with certain conditions, certain age groups, nationalities)

Intervention: What is the intervention or treatment you are interested in? (e.g. form of therapy, medication, surgery)

Comparison: What are you comparing it to? (e.g. comparing ‘treatment of interest’ against another treatment, no treatment?

Outcome: What are you measuring? (e.g. degree of symptoms, behavioural change, quality of life)

Example Question: What is the evidence for the effectiveness of Mediterranean diet in patients with type II diabetes?

P (population)

Middle aged man with type II diabetes

I (intervention)

Mediterranean diet

C (comparison)

Other types of diet

O (outcome)

Glycaemic level

Further reading

Geddes J. Asking structured and focused clinical questions: essential first step of evidence-based practice. Evid Based Mental Health 1999; 2:35-36.

There are formats other than PICO which may be used to structure a clinical question, and the appropriateness of these formats will depend on the type of question and type of studies suitable for addressing the question. 

Example question: How can the discharge procedure from the hospital to the community for people with head injuries be improved?


About improvement or innovation or information (e.g. improve the discharge procedure from the hospital to the community where rehabilitation will continue. What have other people done?)

Client groups

At who is the service aimed? (e.g. people with head injuries)


Where is the service sited? (e.g. community)


What is the change in the service which is being looked for? What would constitute success? How is this being measured? (e.g. continuity of care, patient satisfaction, communication between professionals)


Who delivered the service? (e.g. hospital nurses, community staff, social services)


Type of service being investigated (e.g. community rehabilitation service)


Wildridge V & Bell L. How CLIP became ECLIPSE: a mnemonic to assist in searching for health policy/management information. Health Info Libr J 2002; 19(2):113-5.


Example question: Are balance classes supervised by a physiotherapist effective at reducing falls in the elderly living in aged care facilities?


The demography of the population (age, gender, race); the problem of the population (condition or diagnosis or symptoms) [e.g. elderly]


What is the treatment under investigation? [e.g. balance classes]


Who delivered the intervention? [e.g. physiotherapist]


Change in symptoms of the population; reason for using the exposure [e.g. reducing falls]

Healthcare setting

Where the intervention was delivered (hospital, community centre) [e.g.  aged care facility]


Example Question: What is the impact of an increase in the level of cost-sharing on access to health services for the chronically ill in European countries?


What is the context of the question? [e.g. European countries]


Who are the users/potential users of the outcomes? [e.g. chronically ill]


What is being done to them? [e.g. increased cost-sharing]


What are the alternatives? [e.g. no increase]


How will you measure if the intervention is successful? [e.g. access to health services]


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