Dear Gareth (and List),
Thanks for your mail. A few preliminary thoughts:
* In the past, the medical profession (amongst others) has resisted
change unreasonably (e.g. maternal death rates and the link with being
examined by a doctor rather than a midwife)
* Even 'obvious' things may turn out to be incorrect (e.g. lying babies
on their front to sleep is a good idea)
Therefore, it seems that the alternative to EBM is "myths and legends,
old wives tales", and the fact that you dismiss these is perhaps a
marker of how well EBM has worked. The fact is that in a world where we
often lack a strong empirical basis for our actions, we tend to fall
back on what we were taught or what others do, e.g. Skipping digoxin on
a Sunday (which I was sometimes taught at medical school, not all that
long ago).
I think the real question is around how we go about EBM. What do we
choose as satisfying (the fairly difficult criteria of) "conscientious,
explicit and judicious use of current best evidence in making decisions
about the care of individual patients"? This is a non-trivial question:
In 1345, what would have been the evidence base on which we would have
drawn to decide how to treat plague ?
In light of this, I would suggest that one of the main elements of EBM
has been to put this definition of what counts as being "good evidence"
on a much firmer footing for most clinicians; that is, to provide us
with a method. Those that think this is all 'obvious' might like to read
some of the work by Robert Sharples at UCL
(http://www.ucl.ac.uk/GrandLat/people/sharples/sharples.html) who has
given an interesting talk on the simple absence of any notion of
probability in classical Greece. Once we are able to decide what is
"good" evidence, then half our battle is won.
For me, there are some interesting remaining questions. What should we
do when we have no good evidence? How do we handle evidence that can't
be captured naturally in a statistical or probabilistic form? How do we
integrate different types of evidence? and in order to do this, I think
we need to separate the aims of EBM from the methods used.
Hope that helps,
Matt
--
Dr. M. Williams MRCP(UK)
Clinical Research Fellow
Cancer Research UK
+44 (0)207 269 2953
+44 (0)7384 899570
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