| Evidence Direct: Formulating questions |
|
Searching the evidence base begins by formulating a question, which should be as specific as possible. The following may assist in this process.
1. What is the question about?
| What |
Type of study |
Source |
| Intervention/Therapy |
See RCTs or Systematic Review of RCTs |
Cochrane (including DARE) etc |
|
Diagnosis |
See cohort (cross-sectional) studies or RCTs |
Cochrane (including DARE), PubMed
Clinical Queries, etc |
|
Prognosis |
See observational (e.g. longitudinal)
Cohort Studies |
PubMed Clinical Queries, etc |
|
Aetiology/Harm |
See observational Cohort Studies
or Case-Control Studies |
Cochrane, DARE, PubMed
Clinical Queries, etc |
 Tip: Sometimes it is worth splitting up a question into a series of (PICO'd) questions.
2. Use PICO
| |
Patient or Problem |
Intervention |
Comparison Intervention |
Outcomes |
|
Tips for building |
Starting with your patient, ask "How would I describe a group of patients similar to mine?" Balance precision with brevity. |
Ask, "which main intervention am I considering?" Be specific. |
Ask "what is the main alternative to compare with the intervention?' Again, be specific. |
Ask "What can I hope to accomplish?" or "What could this exposure really affect?" Again, 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?" |
(from Oxford CEBM)
Tip: Outcomes are not always essential to a well-framed question.
3. Click here to see a pdf from Oxford CEBM on Asking Clinical Questions: formulatimng a search strategy. |
