1. Patient or problem 2. Intervention (a cause, prognostic factor, treatment, etc.) 3. Comparison intervention (if necessary) 4. Outcome(s)
Tips for building Starting with your patient, ask "how would I describe a group of patients similar to mine?" Ask "which intervention am I considering?" Be specific. Ask "what is the main alternative to compare with the intervention?" Be specific. Ask "what can I hope to accomplish?" or "what could this exposure really affect?" Be specific.
Example "In patients with heart failure from dilated cardiomyopathy who are in sinus rhythm..." "...would adding anticoagulation with warfarin to standard heart failure therapy..." "...when compared with standard therapy alone..." "...lead to lower mortality or morbidity from thromboembolism. Is this enough to be worth the increased risk of bleeding?"
Reference: Evidence-based Medicine - Sackett, Richardson, Rosenberg and Haynes.