I'm reprinting today's article on "Evidence-Based Medicine," from the Ralph Moss newsletter, Cancer Decisions:
One of our newsletter readers wrote to us
this week about the term 'evidence-based medicine.' "I am hearing this
phrase more and more often," he wrote, "and typically I'm seeing it
used as a means of putting down alternative medicine, as though only
conventional medicine has the right to a place at the table, and
anything else lacks legitimacy."
Certainly
'evidence-based medicine' (EBM) is an interesting and somewhat loaded
phrase, the unambiguous implication of which is that medicine comes in
two varieties - the kind that is based on a solid foundation of
objective evidence, and the kind that is not. Because of the apparently
stark good-versus-bad division it suggests, the phrase lends itself
well to being used as a pejorative by those who are outspokenly opposed
to complementary and alternative medicine (CAM). To such people,
anything other than standard conventional medicine is by definition
unproven, speculative, founded on dubious premises and inherently
inferior. As our perceptive reader pointed out, the term
'evidence-based medicine' is often used by such people as a rhetorical
weapon, a means of devaluing anything that cannot be clearly identified
as mainstream conventional medicine.
Yet this
was not at all the intended meaning of the term as it was originally
conceived. The Evidence-Based Medicine Working Group (EBMWG), a
research collaborative of clinicians and epidemiologists from Ontario's
McMaster University, who first coined the phrase in 1992, were not
attempting to draw a contrast between orthodox and unconventional
medicine; far from it. They were in fact trying to change the medical
profession's entrenched tendency to cling, mainly out of habit, to
procedures and treatments for which there was little if any solid
evidence of effectiveness (EBMWG 1992).
According
to David L. Sackett, MD, one of the original McMaster group, and author
of numerous subsequent papers on the concept of evidence-based
medicine, EBM is intended to be "the conscientious, explicit and
judicious use of current best evidence in making decisions about the
care of individual patients. The practice of evidence-based medicine
means integrating individual clinical experience with the best
available external clinical evidence from systematic research"
(Sackett, 1996).
These are laudable aims, to
be sure. We all want medical care that is based on the best available
evidence rather than on unyielding habit or diehard medical tradition.
But exactly how far has medicine come towards that goal in the decade
and a half since the McMaster University team first advocated the
adoption of EBM? Are most current medical treatments backed by solid
evidence of effectiveness?
Very Few Treatments Are Effective
The venerable British Medical Journal has an offshoot publication, BM Clinical Evidence,
whose mission is to provide physicians and patients with the best
available evidence, garnered wherever possible from randomized,
controlled clinical trials (RCTs), which are considered to be the most
reliable and rigorous standard for measuring treatment effectiveness.
The journal describes itself as "the international source of the best
available evidence for effective health care."
"What
proportion of commonly used treatments are supported by good evidence,
what proportion should not be used or used only with caution, and how
big are the gaps in our knowledge?" asks the publication's Web site
(BMJ 2007).
Of around 2500 treatments so far
reviewed by the journal's distinguished team of advisors, peer
reviewers, experts, information specialists and statisticians, only 13
percent have been found definitely beneficial. A further 23 percent are
rated as likely to be beneficial; 8 percent can be classified as a
trade off between benefits and harms; 6 percent as clearly unlikely to
be beneficial; 4 percent are likely to be ineffective or harmful, and a
whopping 46 percent - almost half of all treatments reviewed - are
rated as being of unknown effectiveness.
As
the journal acknowledges, these figures suggest that most treatment
decisions rest not on solid evidence obtained through properly
conducted clinical trials, but on the individual preferences of
clinicians, unsupported in the majority of cases by any concrete
evidence of benefit.
So, given that very few
of conventional medicine's standard treatments have been demonstrated
to have any clear benefit whatever - and conversely, that a substantial
proportion have been shown to be potentially harmful - it is somewhat
ironic to see the term 'evidence-based medicine' used as a war cry by
those who are virulently opposed to CAM.
Is EBM Compatible with Individualized Patient Care?
Another aspect of the EBM debate that bears close scrutiny is the
question of whether it is always in the patient's best interests to be
treated according to standardized EBM protocols. On the surface, it
seems obvious that patients will benefit when physicians prescribe only
those treatments that have been proven through clinical trials to be
effective. However, there are those, like Erich Loewy, MD, a
bioethicist and professor of medicine at the University of California,
Davis, who argue very persuasively that things are not nearly as black
and white as they seem, and that EBM, as it is currently practiced, may
actually not serve patients well.
In a thought-provoking article for the online medical forum Medscape,
Dr. Loewy cites the danger of using EBM as a standard protocol into
which any patient with a given disease can simply be plugged. He
writes: "To me, as a bioethicist and…a physician who has observed the
evolution of EBM, I am impressed with the danger to physicians,
patients, the educative process, and, ultimately, to the behavior it
encourages. Mindless reliance on EBM does exactly what we do not want
our students to do: convert what is a suffering human being, with a
unique personal life-history, into a specimen of pathophysiology or a
heart murmur" (Loewy, 2007).
Dr. Loewy lists a
number of ways in which EBM may ultimately result in decisions that are
not in the best interests of patients. For example, he writes, "EBM
protocols start out being considered as guideposts and end up being
considered as straightjackets - and straightjackets that are welcomed
by many physicians." One physician actually went so far as to tell Dr.
Loewy that he was enthusiastic about EBM guidelines precisely because
they saved time and did not require him to think.Dr.
Loewy points out that EBM, as practiced in large institutions, can have
the highly undesirable effect of stifling thought and constraining good
diagnostic and clinical judgment. Doctors who 'think outside the box'
and who feel that a particular patient is uniquely suited for a
treatment option that is currently not listed as standard EBM, risk
being disciplined by their institution. "EBM is basically
anti-intellectual," Loewy writes. Thinking, he reminds us, is among the
physician's most important tasks, and EBM protocols, which often
consist of nothing more than standard check sheets, actively discourage
thinking. Worse, because of the potential for EBM to result in
mechanistic treatment decisions that take no account of individual
variation, this method "threatens to separate the patient's uniqueness
further from the physician and would support looking at the disease
instead of at the patient who happens to have that disease."
The
essence of CAM is its focus on the individual and its insistence on the
rationality and centrality of individualized treatment. Of course it is
extremely important to establish treatment guidelines, and to conduct
rigorous research into the effectiveness of currently accepted
standards of treatment. Teaching physicians to evaluate available
treatment options according to whether or not such therapies actually
result in measurable benefit to patients might go a long way towards
improving care (and reducing costs). But when evidence-based medicine
becomes a means of strangling diagnostic skill and reducing patients to
algorithms or numbers on a checklist, medicine can no longer call
itself the art of healing.
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