Questions often spring to mind in a form that makes finding answers in the medical literature a challenge. Dissecting
the question into its component parts and restructuring it so that it is easy to find the answers is an essential first step
in Evidence Based Medicine (EBM). Many questions can be divided into 4 parts:
Many clinical or research questions can be divided into these four components, which we call ‘P I C O’. Try to use all
four parts of the question, if possible.
Different types of questions
The most common type of clinical question is about how to treat a disease or condition. In Evidence Based Medicine (EBM),
treatments and therapies are called ‘interventions’ and such questions are questions of INTERVENTION.
Not all research questions are about interventions. Other types of questions may arise:
What causes the problem? AETIOLOGY, RISK FACTORS
What is the frequency of the problem? FREQUENCY
Does this person have the problem? DIAGNOSIS
Who will get the problem? PROGNOSIS, PREDICTION
In each case the P I C O method can be used to formulate the question, as shown in the following examples. You can use the
same approach to research qualitative questions about health issues of a more general nature (i.e. PHENOMENA). In this case,
the question will consist of ‘P’ and ‘O’ only.
The studies that you will need to find in the course of your work will be different for each type of question and we will
discuss this further in the next section.