The first step in developing a well-built question is to identify the patient problem or population [P] by describing either the patient’s chief complaint or by generalising the patient’s condition to a larger population. The problem is further shaped or refined by the most important characteristics that might influence the results such as:
In Mr. Logan’s case, we know the chief complaint is discoloration of his front teeth and that coffee and tobacco are contributing factors. So, in addition to the chief complaint, age, and current habits, previous behaviors may influence the decision as to which treatment might be most appropriate.
Identifying the Intervention [I] is the second step in the PICO process. It is important to identify what you plan to do for that patient. This may include the use of a specific diagnostic test, treatment, adjunctive therapy, medication, or the recommendation to the patient to use a product or procedure. The intervention is the main consideration for that patient.4 In Mr. Logan’s case, the intervention being considered is the Crest Whitestrips™ since he has specifically asked about them. This also keeps the process patient-centred.
The third phase of the well-built question is the Comparison [C], which is the main alternative (intervention) you are considering.2 It should be specific and limited to one alternative choice, usually the gold standard, in order to facilitate an effective computerized search. The Comparison is the only optional component in the PICO question since there may not be an alternative, however when there is one, it should be used. In our case, we have selected the custom trays for at-home bleaching as the main alternative.
The final aspect of the PICO question is the outcome [O]. This specifies the result(s) of what you plan to accomplish, improve, or affect, and it should be measurable. Examples of outcomes are relieving or eliminating specific symptoms, improving or maintaining function, and enhancing aesthetics. In Mr. Logan’s case, you are seeking evidence to demonstrate the effectiveness of the whitening/bleaching treatment under a given set of conditions, i.e., effective in whitening his teeth within one week so they appear as white as they were when he was 25 years old. Outcomes yield better search results when defining them in specific terms. "More effective or just as effective" is not acceptable unless it describes how the intervention is more effective. For our example, just as effective in whitening teeth within one week is the desired outcome.