Finding answers to questions in evidence based medicine (EBM)

By Atle Klovning

1. Formulate a searchable question
2. Search
3. Critical appraisal

Finding answers to clinical questions is a great challenge, and  Scott Richardson's contribution to forming structured 4-part questions as described below, is a prerequisite.

1. Who?

2. What?

3. Alternatively?

4. Outcome?

In children
with acute otitis media
aged 2-4 years

 Antibiotics

No treatment except paracetamol
Once daily regimens
Nasal decongestants

No pain after two days?
Side-effects

In men with 
cancer of the prostate
younger than n 70 years

Staging with MRI

Gleason scoring

Predictive value?
Likelihood ratio?
 

2. Search
When "looking for answers", use the sources in the priority listed below, structured into a "7-step way for finding best evidence":

1 The Cochrane library - the ultimate choice, a multinational effort systematically organizing information
2 Secondary Journals - "let others critically appraise and present articles"
3 MEDLINE - one of many databases which are free and with different interfaces that might help you
4 Primary Journals on the web, often searchable, and often in flutist .pdf versions
5 Guidelines on the web, well aware of the varying quality
6 Internet - the distressingly, unsorted information megaworld where no quality filtering exists
7 Mailbases for posting questions I still have not found an answer to

3. Critical appraisal
 Basically, critical appraisal is based on 3 steps:
1. Internal validity (How well is this study performed?)
2. Results (What does it show?)
3. External validity (Can I use it?)

4. EBM for beginners 
Those who need a general introduction into EBM, I have organized general link sites which serve as educational starting points into the EBM world.

Many of us are disillusioned by the overwhelming information now available at our fingertips at the computer- and do not know where or how to start looking for answers to their questions. As a result of my own failures and struggling, I have tried to compile a ranking list of where to look.

Searching
 

1. The Cochrane library
Remember that if you are are looking quality assessed RCTs, you need to add "and CCTR" when looking for a publication type, unless you also want to search the full CCTR, called CENTRAL.  

2. Secondary journals
These are the journals where someone has read a paper, summarised and critically appraised it, giving you a bottom-line to share in the decision-making with your patient.

3. MEDLINE 

Other Medline interfaces

These are Norwegian sites for searching books, papers, the net etc.:

KnowledgeFinder Medline
Here is the wonderful spot where you can just write your 4-part question, like "In children, what is the best treatment of nocturnal enuresis?" and voila, by means of fuzzy logic it is turned into a search. The results are presented as a list where the assumed most relevant papers are listed first, instead of chronologically as in ordinary Medline. It requires subscription today

 

4. Primary journals

General journals 

Epidemiology

Laboratory journals 

Family medicine journals 

5. Guidelines  

6. Internet

7. Mailbases

Mailbases are useful for following debates on issues of interest toy ou,
and questions may be posted to the list members, but you are expected to have
done your homework and searched on your own before posting your question.
There are over 2000 lists at:
MailbaseElectronic Mailing List Service

Try joining the Evidence-based health list:
http://www.jiscmail.ac.uk/cgi-bin/wa.exe?SUBED1=evidence-based-health&A=1  

General link sites which are great educational starting points into the EBM world  

 

 

Author: Dr. Atle Klovning, MD
First published: 01 November, 1997
Last editorial revision: 02 Feb, 2004
Last technical revision: 19 March, 2001