Evidence Based Medicine
Are Doctors Just Playing Hunches?
By Christine Gorman, Feb. 15, 2007
See
our full line of Nutritional supplements
Nobody pretends medicine is easy, but if there's one thing we ought to be able
to rely on, it's that the doctors looking out for us are doing more than playing
hunches. We take certain medicines because they work, right? We go into the
operating room for certain procedures because they'll make us well, don't we?
Well, maybe. More and more, however, doctors are making the unnerving case
that no matter how reliable a drug or other treatment appears to be, too often
there's simply little hard evidence that it would make a long-term difference
in a person's quality of life or prolonged survival. Obviously, drugs are tested
rigorously to show that they are safe and effective before they are approved
by the U.S. and other developed countries. But a clinical study is not the real
world, and just because a drug leads to a statistically significant improvement
in, say, cholesterol levels doesn't guarantee that the desired effect--a healthier
heart and a longer life--will follow. Often your doctor is left to make prescription
decisions based at least in part on faith, bias or even an educated guess. That
ought to be enough to spook even the least jumpy patient, but the fact is, recognizing
just what a roll of the dice medicine can be may be a good thing.
Increasingly, doctors seeking to provide their patients with the best possible
care are exploring what is known as evidence-based medicine--a hard, cold, empirical
look at what works, what doesn't and how to distinguish between the two. It's
not enough to prove that a particular blood test or CT scan really spots cancer,
for example. You also need to know whether early detection of that cancer would
make a difference in your ability to respond to treatment or it merely means
that you would die at the same point but learn about your illness earlier than
you would have without the test.
Evidence-based medicine, which uses volumes of studies and show-me skepticism
to answer such questions, is now being taught--with varying degrees of success--at
every medical school in North America. It has been extraordinarily successful
in shooting down some of the most cherished beliefs in health care, like the
idea that long-term hormone-replacement therapy would help prevent heart disease
in women. And it has clearly saved lives. Many doctors used to give anti-arrhythmia
drugs to everyone who experienced irregular heartbeats after a heart attack
because severely irregular beats could rapidly prove fatal. But then came the
results of a randomized trial showing that patients with only mildly irregular
heartbeats were more likely to die if given the anti-arrhythmia medication than
their untreated counterparts were. Doctors now prescribe more judiciously, though
treatment still saves lives in the case of severe arrhythmias.
Advocates believe that evidence-based medicine can go much further, reducing
the reliance on expert opinion and overturning the flawed assumptions and even
financial incentives that underlie many decisions. "This is a whole way
of looking at the world," says Dr. Gordon Guyatt of McMaster University
in Hamilton, Ont., who coined the term and is a pioneer of the evidence-based
movement.
But is such certainty possible--or even desirable? Medicine, after all, is
a personalized service, one built around the uniqueness of each patient and
the skilled physician's ability to design care accordingly. "I'm worried
about training a generation of physicians who don't have the other skills they
need for the optimal practice of medicine," says Dr. Mark Tonelli, a pulmonary-care
specialist at the University of Washington in Seattle. "They can read the
scientific literature, understand the statistics, but they don't understand
how that should influence their treatment of the individual in front of them."
What's more, some insurance companies have been very aggressive in using evidence-based
arguments to deny payment for untested treatments--a circular problem, because
how do you create the evidence the insurers demand unless you test the untested?
Whatever the merits of evidence-based medicine, it got off to a rocky start.
When Guyatt began championing it back in the 1990s, he called it "scientific
medicine," but he learned quickly that if you want to start a revolution,
it helps to pick the right slogan. Many of his colleagues were outraged by the
implied insult to their expertise. So he quickly went with "evidence-based,"
and tempers cooled.
Guyatt's ideas complemented the work of the Cochrane Collaboration, an international
network of researchers, physicians and others that was founded in 1993 to systematically
gather and evaluate the knowledge found in medical research. The organization
aggregates all published scientific studies on a particular treatment question
to get a sense of the field. Then reviewers carefully consider the design of
the research to determine just how strong the evidence is. One of their most
famous reports was a 2005 finding based on 139 studies showing that there was
"no credible evidence" that the vaccine against measles, mumps and
rubella was involved in the development of either autism or Crohn's disease.
Guyatt and another doctor, David Sackett, wanted to go a step further by making
sure doctors used the evidence that was collected and ranked. Many physicians
began doing just that, but there have been a few nasty surprises.
Consider the case of Dr. Daniel Merenstein, a family-medicine physician trained
in evidence-based practice. In 1999 Merenstein examined a healthy 53-year-old
man who showed no signs of prostate cancer. As he had been taught, Merenstein
explained to his patient that there are advantages and disadvantages to having
a blood test for prostate-specific antigen (PSA). The test can lead to early
detection of prostate cancer but also to unnecessary biopsies and even treatment--with
all its attendant risks of impotence and incontinence--for a cancer that might
have grown so slowly that it didn't need immediate attention. And for aggressive
prostate cancers, there is little evidence that early detection makes a difference
in whether treatment could save your life. As a result, the patient did not
get a PSA test.
Unfortunately, several years later, the patient was found to have a very aggressive
and incurable prostate cancer. He sued Merenstein for not ordering a PSA test,
and a jury agreed--despite the lack of evidence that it would have made a difference.
Most doctors in the plaintiff's state, the lawyers showed, would have ignored
the debate and simply ordered the test. Although Merenstein was found not liable,
the residency program that trained him in evidence-based practice was--to the
tune of $1 million.
Even champions of evidence-based practice acknowledge that the approach has
limits. "Some things can't be tested in randomized trials, and some things
are so obvious, they don't need it," says Dr. Paul Glasziou, director of
the Center for Evidence-Based Medicine in Oxford, England. There have never
been randomized trials to show that giving electrical shocks to a heart that
has stopped beating saves more lives than doing nothing, for example. Similarly,
giving antibiotics to treat pneumonia has never been rigorously tested from
a scientific point of view. It's clear to everyone, however, that if you want
to survive a bout of bacterial pneumonia, antibiotics are your best bet, and
nobody would want to go into cardiac arrest without a crash cart handy. "Where
randomized trials are most important is where you're trying to affect a long-term
condition, like stroke or cancer," Glasziou says.
Finally, the very definition of evidence-based medicine is something of a moving
target. Physicians who encouraged their female patients to take hormone-replacement
therapy to prevent heart problems later on were practicing a kind of evidence-based
medicine, since the best available evidence at the time--observational studies
and the like--suggested a benefit. Of course, when a randomized controlled trial
showed otherwise, the advice changed. Even at that, the case is not entirely
closed. Some researchers now believe there may be a window of opportunity right
around the years of menopause during which hormone-replacement therapy could
help the heart. Proving that would, naturally, require another study.
All the same, few people deny that the trend in medicine is increasingly to
be guided, if not governed, by the data--an idea that is spreading to other
fields as well. Evidence-based practice is now being taught in nursing, general
education and even philanthropy, thanks to the influence of the Bill and Melinda
Gates Foundation, a results-based group if ever there was one. You could see
even the political fights over global warming as the birth pangs of the new
practice of evidence-based policy.
But it is in medicine that the practice will have the most emotional impact.
All patients would probably benefit if their doctors were abreast of the latest
data, but none would benefit from being reduced to one of those statistical
points. "You have to be able to take a good history and do a physical examination,"
Guyatt says. "And you have to have an understanding of patients' values
and preferences." As much as some physicians might wish it otherwise, there
is still as much art to medicine as there is science.
Shame:
A Major Reason Why Most Medical Doctors
Don't Change Their Views
By Frank Davidoff, British Medical Journal 2002;324:623-624
March 16, 2002
In the 1960s the results of a large randomized controlled study by the University
Group Diabetes Program showed that tolbutamide, virtually the only blood sugar
lowering agent available at the time in pill form, was associated with a significant
increase in mortality in patients who developed myocardial infarction. The obvious
response from the medical profession should have been gratitude: here was an
important way to improve the safety of clinical practice. But in fact the response
was doubt, outrage, even legal proceedings against the investigators; the controversy
went on for years.
Why?
An important clue surfaced at the annual meeting of the American Diabetes
Association soon after the study was published. During the discussion a
practitioner stood up and said he simply could not, and would not, accept
the findings, because admitting to his patients that he had been using an
unsafe treatment would shame him in their eyes. Other examples of such
reactions to improvement efforts are not hard to find.
Indeed, it is arguable that shame is the universal dark side of improvement.
After all, improvement means that, however good your performance has been,
it is not as good as it could be. As such, the experience of shame helps to
explain why improvement, which ought to be a "no brainer", is generally
such
a slow and difficult process.
What is it about shame that makes it so hard to deal with? Along with
embarrassment and guilt, shame is one of the emotions that motivate moral
behavior. Current thinking suggests that shame is so devastating because it
goes right to the core of a person's identity, making them feel exposed,
inferior, degraded; it leads to avoidance, to silence.
The enormous power of shame is apparent in the adoption of shaming by many
human rights organizations as their principal lever for social change; on
the flip side lies the obvious social corrosiveness of "shameless"
behavior.
Despite its potential importance in medical life, shame has received little
attention in the medical literature: a search on the term shame in Medline
in November 2001 yielded only 947 references out of the millions indexed. In
a sense, shame is the "elephant in the room": something so big and
disturbing that we don't even see it, despite the fact that we keep bumping
into it. An important exception to this blindness to medical shame is a
paper published in 1987 by the psychiatrist Aaron Lazare which reminded us
that patients commonly see their diseases as defects, inadequacies, or
shortcomings, and that visits to doctors' surgeries and hospitals involve
potentially humiliating physical and psychological exposure.
Patients respond by avoiding the healthcare system, withholding information,
complaining, and suing. Doctors too can feel shamed in medical encounters,
which Lazare suggests contributes to dissatisfaction with clinical practice.
Indeed, much of the extreme distress of doctors who are sued for malpractice
appears to be attributable to the shame rather than to the financial losses.
Also, who can doubt that a major concern underlying the controversy
currently raging over mandatory reporting of medical errors is the fear of
being shamed? Doctors may, in fact, be particularly vulnerable to shame,
since they are self-selected for perfectionism when they choose to enter the
profession. Moreover, the use of shaming as punishment for shortcomings and
"moral errors" committed by medical students and trainees such as
lack of
sufficient dedication, hard work, and a proper reverence for role
obligations probably contributes further to the extreme sensitivity of
doctors to shaming.
What are the lessons here for those working to improve the quality and
safety of medical care?
Firstly, we should recognize that shame is a powerful force in slowing or
preventing improvement and that unless it is confronted and dealt with
progress in improvement will be slow. Secondly, we should also recognize
that shame is a fundamental human emotion and not about to go away. Once
these ideas are understood, the work of mitigating and managing shame can
flourish.
This work has, of course, been under way for some time. The move away from
"cutting off the tail of the performance curve" that is, getting rid
of bad
apples towards "shifting the whole curve" as the basic strategy in
quality
improvement and the recognition that medical error results as much from
malfunctioning systems as from incompetent practitioners are important
developments in this regard.
They have helped to minimize challenges to the integrity of healthcare
workers and support the transformation of medicine from a culture of blame
to a culture of safety.
But quality improvement has another powerful tool for managing shame.
Bringing issues of quality and safety out of the shadows can, by itself,
remove some of the sting associated with improvement. After all, how
shameful can these issues be if they are being widely shared and openly
discussed?
Here is where reports by public bodies and journals like Quality and Safety
in Health Care come in. More specifically, such a journal supports three
major elements autonomy, mastery, and connectedness that motivate people to
learn and improve, bolstering their competence and their sense of self
worth, and thus serving as antidotes to shame.
|