How much of orthodox medicine is EBM?
Scientific heavyweights deplore the NHS money wasted on unproved and
disproved treatments used by CAM practitioners 1,2, but a CAM proponent
responds that “The BMJ reckons that 50% of the treatments we use in
general practice aren’t proven, and 5% are pretty harmful but we are still
using them.”3 Dr Lewith’s data were taken from the BMJ Clinical Evidence
website 4. A pie chart indicates that, of about 2500 treatments supported
by good evidence, only 15% of treatments were rated as beneficial, 22% as
likely to be beneficial, 7% part-beneficial and part harmful, 5% unlikely
to be beneficial, 4% likely to be ineffective or harmful, and in the
remaining 47% the effect of the treatment was “unknown”. The text says,
“The figures suggest that the research community has a large task ahead
and that most decisions about treatments still rest on the individual
judgements of clinicians and patients.” I have visited the site again to
see if the situation had changed. It has, but not for the better. On
09/10/07 treatments rated “beneficial” had decreased from 15% to 13%. The
associated text is unchanged.
I studied in detail the management of acute low back pain, which is
an extremely common and well-investigated condition. BMJ Best Treatments
reports that back pain affects 70-85% of all adults, and each year almost
half of us get back pain that lasts at least a day. There are 18
treatments for acute low back pain which have been tested by RCT, of which
two (11%) were graded “beneficial”, and 13 (72%) are labelled “unknown”.
The attached Table taken from BMJ Best Treatments shows all of the 18
treatments for acute low back pain and their rated effect. Here is a
curious situation. A condition that is extremely common, and for which
many treatments have been intensively researched, has an even higher-than-
average proportion of treatments that are labelled “unknown” efficacy, or
in other places “need further study”. There must be some mistake.
The solution to the mystery is that the label “unknown” does not
mean, “We have no knowledge of the effect of this treatment because it has
not been tested in an RCT”. Astonishingly, it means, “We have tested this
treatment in several RCTs, but on balance there is currently no convincing
evidence that it is effective for this condition.” So really the efficacy
of these 13 treatments for acute back pain is not “unknown” but “not
I conclude that Dr Lewith’s interpretation of the pie chart is highly
misleading. The research community has been commendably diligent, but of
course RCTs often fail to find that certain treatments are effective.
Euphemisms such as “unknown” or “needs more study” for the inefficacy of
such treatments may sooth the feelings of proponents of those treatments
that have so far failed to show efficacy, but it does an injustice to the
researchers who obtained these data, and misleads both practitioners and
patients about the extent to which orthodox medicine is evidence-based.
It is particularly ironic that CAM therapies are over-represented in the
not-shown-to-be-effective category, so if anyone should be concerned about
lack of evidence it should be CAM practitioners rather than conventional
Grading of the efficacy of treatments for acute low back pain
Treatments that work n=2 (11%)
Non-steroidal anti-inflammatory drugs (NSAID)
…that are likely to work n=2 (11%)
Multi-disciplinary treatment programmes (Drs, psychologists,
… that work, but harm may outweigh benefit n=1 (6%)
… that “need further study” (aka “unknown”) n=13 (72%)
Back schools Painkillers
Behaviour therapy Temperature treatments
Epidural steroid injections Transcutaneous electrical nerve
… that are unlikely to work n=1 (6%)
Exercise, including back exercises.
… that are likely to be ineffective or harmful n=1 (6%)
1. Kamerow D. Wham, bang, thank you CAM. BMJ 2007;335:647 (29 September)
2. Calquhoun D. What to do about CAM. BMJ 2007; 335:736 (13 October)
3. Lewith G. (cited by Cope J) Healthwriter. April 2007, p 2.
4. http://clinicalevidence.com/ceweb/about/ knowledge/jsp visited 06-05-
Competing interests: No competing interests