Your question needs to identify the key problem, what treatments/tests are you preparing for the patient, what alternative treatments (if any) are being considered, and what is the desired outcome to promote or avoid.
P = Problem: How do you describe a group of patients similar to yours? What are the most important characteristics of the patient? This may include the primary problem, disease, or co-existing conditions. Sometimes the gender, age or race of a patient might be relevant to the diagnosis or treatment of a disease.
I = Intervention: Which main intervention, prognostic factor, or exposure are you considering? What do you want to do for the patient? Prescribe a drug? Order a test? Order surgery? Or what factor may influence the prognosis of the patient - age, co-existing problems, or previous exposure?
C = Comparison: What is the main alternative to compare with the intervention? Are you trying to decide between two drugs, a drug and no medication or placebo, or two diagnostic tests? Your clinical question may not always have a specific comparison.
O = Outcome: What do you hope to accomplish, measure, improve or affect? What are you doing for the patient? Relieve or eliminate the symptoms? Reduce the adverse events? Improve function or test scores?