Dear Kev
You write
"The conclusion seems to be that at least most of the time,
a less than comprehensive search will give us the same outcome
as a comprehensive search. Unfortunately, there may be occasions that this is not so.
The trouble is, we cannot tell when those occasions will occur."
Please let me suggest that by letting perfect become the enemy of the good,
we may be doing more harm than good to the cause of EBM.
EBM began as a “bottom-up” paradigm that taught residents to ask answerable
and focused questions, search the literature in a transparent and reproducible way
to find the best evidence and to critically appraise it in an explicit and
structured manner, often using mathematical analyses to give a clear idea of the strength,
statistical significance and possible clinical significance of the results.
Unfortunately it is no longer an amateurs’ enterprise.
Journals now insist on numerous boxes being ticked before they
will even consider an review article for publication.
Multiple data bases have to be explored, the references in the papers
need to be hand-searched for new references,
clinical trials registers and conference proceedings scrutinised
and pharmaceutical companies and individual researchers must
have been contacted for unpublished data and ongoing trials.
Only organisations with very deep pockets can afford this anymore.
Vested interests and jumped into the void.
Now we have even Cochrane Meta analysis,
written up by persons with direct conflicts of interests declared.
Als-Nielsen and colleagues have shown that association
with for profit organisations had little impact on treatment effect
but the conclusions were more positive due to biased interpretation
of trial results (Als-Nielsen et al 2003). Lundh and colleagues have shown that
publication of industry-supported trials was associated with an increase
in journal impact factors and revenue (Lundh et al 2010).
Smith (2010), the former editor of the BMJ, has suggested that
publishing the RCT sponsored by one drug company could
yield a million dollars in the sales of reprints alone.
We can counteract this form of biased interpretation only if allow
less comprehensive searches done be independent
researchers to challenge these 'comprehensive' reports.
I must declare that most of this stuff I had researched for paper on EBM
published elsewhere (Evidence Based Medicine: Making It Better)
Jacob Puliyel MD MRCP M Phil
Head of Pediatrics
St Stephens Hospital
Delhi
|