One of the fundamental skills required for practising EBM is
the asking of well-built clinical questions. To benefit patients and clinicians,
such questions need to be both directly relevant to patients' problems and
phrased in ways that direct your search to relevant and precise answers. In
practice, well-built clinical questions usually contain four elements,
summarised below.
Patient or problem
Starting with your patient ask “How would I describe a
group of patients similar to mine?” Balance your precision with brevity
Eg in patients with heart failure from dilated cardiomyopathy
who are in sinus rhythm...
Intervention
Ask “Which main intervention am I considering?” Be
specific
Eg … would adding anticoagulation with warfarin to standard
heart failure therapy …
Comparison Intervention
Ask “What is the main alternative to compare with the
intervention?” Again, be specific.
Eg … when compared with standard therapy alone….
Outcome
Ask “What can I hope to accomplish?” or “What could
this therapy really effect?” Again be specific.
Eg. … lead to lower mortality or morbidity from
thromboembolism. Is this enough to be worth the increased risk of bleeding?
One of the benefits of careful and thoughtful
question-forming is that the search for evidence is easier. The well-formed
question makes it relatively straightforward to elicit and combine the
appropriate terms needed to represent your need for information in the query
language of whichever searching service is available to you.