Evidence-based Medicine Toolkit

Asking answerable questionsThe four elements of a well-formed clinical question are:1 Patient or Problem2 Intervention3 Comparison intervention (if appropriate)4 Outcome(s)The terms you identify from this process will form the basis of yoursearch for evidence and the question as your guide in assessing itsrelevance.Bear in mind that how specific you are will affect the outcomeof your search: general terms (such as ‘heart failure’) will give you abroad search, while more specific terms (for example, ‘congestiveheart failure’) will narrow the search.Also, you should think about alternative ways or aspects of describingyour question (for example, New York Heart AssociationClassification).Element Tips Specific examplePatient or problemInterventionComparisoninterventionOutcomeStarting with yourpatient ask ‘How wouldI describe a group ofpatients similar to mine?’Ask ‘Which mainintervention am Iconsidering?’Ask ‘What is the mainalternative to comparewith the intervention?’Ask ‘What can I hope toaccomplish?’ or ‘Whatcould this exposure reallyaffect?’‘In women over40 with heartfailure from dilatedcardiomyopathy …’‘… would addinganticoagulationwith warfarin tostandard heart failuretherapy…’‘… when comparedwith standard therapyalone …’‘… lead to lowermortality ormorbidity fromthromboembolism.’3